Post Opening Project Evaluation
M1 Junctions 6a to 10 Widening One Year
After Study
October 2010
M1 Junctions 6a to 10 Widening One Year After Study
Contents
Section
Executive Summary
1. Introduction
Background to the Scheme
Scheme Location
Scheme Description
The Need for the Scheme
Scheme Objectives
History of the Scheme
Post Opening Project Evaluation
2. Data Collection
Introduction
Traffic Counts
Journey Times
Accidents
Site Visit
Appraisal Documentation
Consultation
3. Traffic Analysis
Introduction
Traffic Volume Trends
Traffic Flow Changes on the M1
Traffic Flow Changes on Surrounding Network
Changes in Journey Times
Comparison of Forecast and Observed Traffic Impacts
4. The Safety Objective
Introduction
Personal Injury Accidents
Accident Rates on M1 compared to National Average
Accident Significance Testing
Predicted vs. Observed Accidents
Personal Security
5. The Economy Objective
Introduction
Predicted Benefits
Outturn Benefits
Scheme Costs
Benefit Cost Ratio (BCR)
Journey Time Reliability
Wider Economic Impacts
6. The Environment Objective
Introduction
Data Collection
Traffic Forecasts Evaluation
Noise
Air Quality
Greenhouse Gases
Landscape
Page
4 7 7 7 8 9 9 9 10 11 11 11 13 13 14 14 14 15 15 15 16 17 18 20 24 24 24 28 29 29 30 32 32 32 33 37 37 38 39 41 41 41 43 44 46 47 49 2
M1 Junctions 6a to 10 Widening One Year After Study
Biodiversity
Heritage of Historic Resources
Water Environment
Physical Fitness
Journey Ambience
7. The Accessibility and Integration Objectives
Introduction
Accessibility
Integration
8. Appraisal and Evaluation Summary Tables
Appraisal Summary Table (August 2007)
Evaluation Summary Table
9. Conclusions
56 60 64 66 67 71 71 71 73 75 75 75 79 Appendices
Appendix A - Glossary of Terms
Appendix B – Environmental Information Requested
Appendix C – Visual Impact of Scheme
81 84 86 The maps in this document are reproduced from Ordnance Survey material with the permission of
Ordnance Survey on behalf of the Controller of Her Majesty's Stationery Office © Crown
copyright. Unauthorised reproduction infringes Crown copyright and may lead to prosecution or
civil proceedings. Highways Agency Licence No. 100018928. Published 2010.
3
M1 Junctions 6a to 10 Widening One Year After Study
Executive Summary
Scheme Description
The M1 Junction 6a to 10 widening scheme in Hertfordshire opened in December 2008 and brought
this section of the M1 to a full standard four lane motorway with continuous hard shoulders. This was
achieved by widening the following sections from 3 to 4 lanes:

Junctions 6a to 7 southbound;

Junctions 8 to 9 northbound and southbound;

Junctions 9 to 10 southbound; and

Also new parallel (‘Collector-Distributor’) roads were constructed between Junctions 7 and 8 to
cater for local traffic travelling between Hemel Hempstead and St Albans.
It was originally envisaged that the additional capacity provided by this scheme would be used as an
opportunity to trial a High Occupancy Vehicle (HOV) lane. This was proposal was subsequently
dropped during scheme construction. However, implementation of Controlled Motorway (CM) has
occurred and is currently operational with variable advisory speed limits. It should be noted that the
scheme appraisal did not consider the impacts of a HOV lane or the Controlled Motorway.
Scheme Objectives
Objectives (from AST, August 2007)
Objective Achieved?
Reduce Congestion
Yes
Improve Journey Time Reliability
Yes
Reduce Accidents
Yes
Key Findings
 The objectives of this scheme to reduce congestion, improve reliability and reduce accidents have
all been met based on the evidence available at this one year after opening stage.
 There is evidence of limited traffic re-assignment onto the M1 motorway from nearby parallel roads
in the local area.
 The observed journey times and safety benefits almost match those forecast to occur.
 Observed northbound traffic volumes correlate well with the forecasts, whilst the southbound traffic
flows are generally higher than forecast
 The investment cost of the scheme was less than forecast – despite the additional costs incurred
implementing the controlled motorway.
 The environment mitigation measures, including extensive planting, have largely been put in place.
Summary of Scheme Impacts
Traffic
Traffic Volume Changes


Traffic flows on the improved section of the M1 have increased slightly since scheme opening.
There has been a general decrease in traffic flows on the majority of the local roads in the vicinity of
the scheme since opening. This indicates that the slight increase in traffic observed on the M1 could
be a result of re-assignment from these routes.
4
M1 Junctions 6a to 10 Widening One Year After Study
Journey Times



Post opening journey times are consistently lower in both directions. The average journey time is
now approximately 15 minutes whereas previously the journey time ranged from 18 minutes to 25
minutes during peak periods.
There is less variability in journey times since the scheme opened with peak journey times similar to
those recorded in the off peak.
The scheme has therefore achieved its objective of reducing congestion.
Forecasting Accuracy

Observed northbound traffic volumes are very close to predicted indicating a high degree of
forecasting accuracy.
 Observed southbound traffic flows are higher than predicted. The reasons for these forecasting
inaccuracies are unclear following a review of the appraisal documentation.
 Traffic flows on the A414 (former M10) are considerably lower than forecast, potentially due to the
traffic modelling not taking account of the downgrading of this route following scheme opening.
 The observed journey time saving of three minutes along the extent of the scheme is almost the
same as forecast.
Safety
Accident and Casualty Savings





An annual saving of 222 accidents (and 153 casualties) across the COBA modelled network
compared to five years before opening indicates that the scheme has been successful in meeting its
objective to reduce accidents.
There is no evidence of any accident clusters since the scheme opened.
The observed accident saving is almost the same as predicted which shows that the forecasting
approach was robust in this instance.
Statistical tests show that the change in accident rate is not a result of chance alone, so therefore
can be attributed to the scheme.
The accident rate on the M1 is now lower than the national average for this type of road, compared
to an accident rate five times the national average before the scheme opened.
Personal Security

The impact on personal security is slight beneficial as expected due to improved journey time
reliability and increased CCTV provision.
Environment



The environmental mitigation measures have largely been implemented in line with proposals.
Consultation with Parish Councils has identified local areas of concern such as tunnel lighting.
Based on the information available environmental sub-objectives at the one year after stage are
considered to be as expected.
Accessibility

It is considered that the AST forecast for option values is valid and that no more detailed evaluation
would reveal any changes connected to the scheme.
 This scheme has had no direct impact on public transport provision, therefore the AST (Appraisal
Summary Table) assessment of neutral impact is considered to be valid in this instance.
 The scheme has maintained the existing crossing facilities facilitating movement across the M1. The
severance impact is therefore neutral as expected.
Integration
 The scheme has not had an impact on the provision of public transport interchange as expected.
 The scheme integrates well with the objectives set out in local, regional and national policies as
expected.
5
M1 Junctions 6a to 10 Widening One Year After Study
Summary of Scheme Economic Performance
All figures in 2002 Prices discounted to 2002 at 3.5%
Journey Time Benefit
Safety Benefits
Other Benefits (Vehicle
operating costs,
Construction delay,
Maintenance delay)
Total 60 Year Benefits
(PVB)
Present Value Costs
Benefit Cost Ratio
(BCR)
Pre Scheme forecast
Post-scheme re-forecast
£1,235.7m
£1,118.7m
£773.4m
£763.1m
-£4.8m
-£4.8m*
£2,004.3m
£1,877.0m
£290.0m
£275.4m
6.9
6.8
* Same as forecast assumed due to low magnitude of benefits


The re-forecast safety benefits are almost exactly the same as predicted (although evaluation was
undertaken using only one year’s worth of observed data).
The outturn scheme costs are lower than forecast. This is despite the outturn figures including
elements of controlled motorway which were not considered in the forecast.

The outturn BCR is slightly lower than forecast due lower than predicted journey times (although it
is recognised this is a conservative estimate) and fewer accident savings. However, the scheme
still represents good value for money.

An analysis of the standard deviation of before and after journey times indicates that journey time
reliability has improved as a result of the increased capacity provided by the scheme.

The scheme has contributed to the growth aspirations of the MKSM (Milton Keynes South
Midlands) area by providing additional capacity and improved journey times on the main strategic
highway through the area.
6
M1 Junctions 6a to 10 Widening One Year After Study
1.
Introduction
Background to the Scheme
1.1
The M1 Junction 6a to 10 widening scheme is a major Highways Agency project to increase
the number of lanes on the M1 from three to four in Hertfordshire. The additional capacity
provided by the scheme was initially earmarked as suitable to implement a HOV (High
Occupancy Vehicle Lane). However, this was subsequently dropped in favour of a ‘Controlled
Motorway’ which although now operational, was not part of the appraised scheme.
1.2
In addition to the widening, the infrastructure required for operating a Controlled Motorway
was also installed at the same time. The appraisal for the widening scheme (both costs
and benefits) did not include provision for the Controlled Motorway which is currently
operational between Junctions 6a to 10 with variable advisory speed limits. The implications
this has on the evaluation are considered at the relevant stages of this report.
1.3
Opened in December 2008, this study evaluates the impact of the scheme one year after
(OYA) opening.
Scheme Location
1.4
The M1 motorway from London to Leeds is one of the busiest and most important roads in
the country, providing a key link between London, the Midlands, and the North. The section
between Junctions 6a to 10 is approximately 17km (10 miles) long stretching from the M25 to
Luton. Figure 1.1 shows the location of the scheme in a regional context.
Figure 1.1 - Location of the M1 Junction 6a to 10 Improvements
7
M1 Junctions 6a to 10 Widening One Year After Study
Scheme Description
1.5
The scheme aimed to bring the M1 between Junctions 6a to 10 up to a full standard four lane
motorway with continuous hard shoulders. This was achieved by widening the following
sections from 3 to 4 lanes:

Junctions 6a to 7 southbound;

Junctions 8 to 9 northbound and southbound;

Junctions 9 to 10 southbound; and

New parallel ‘Collector-Distributor’ roads were constructed between Junctions 7 and 8 to
cater for local traffic travelling between Hemel Hempstead and St Albans.
The facilitating works to allow the above improvements to take place included the following:




Junction 7 – Carriageway realignment of the north and southbound carriageway to the
north of the junction and the southbound carriageway south of the junction including
realigning the adjacent slip roads;
Junction 8 – Repositioning the slip roads to the west of the junction and alteration of the
slip road arrangement to the east of the junction;
Junction 9 – Realigning the slip roads on all approaches and exits from the M1;
Junction 10 – Realigning the slip roads on all approaches and exits from the M1
increasing the overall width of the junction;

1.6
Widening or replacement of 11 underbridges; and

Replacement of 7 overbridges.
Figure 1.2 shows a more detailed plan of the scheme, with the junctions highlighted.
Figure 1.2 - M1 Junction 6a to 10 Scheme Detail
8
M1 Junctions 6a to 10 Widening One Year After Study
The Need for the Scheme
1.7
Since its construction in the late 1950’s and early 1960’s the M1 has become a very heavily
used strategic link between London, the Midlands, and the North, and the section between
Junctions 6a to 10 through Hertfordshire is one of the busiest stretches of the M1. At peak
times extensive queues occurred between the M25 and Luton especially at junctions and on
the steeper gradients.
1.8
Near junction 8 (Hemel Hempstead) traffic travelling between the former M10 and A414 had
to use a short section of the M1 between Junctions 7 and 8. This resulted in a mixing of long
distance and local traffic resulting in a reduction in the effective capacity of this section (due
to weaving traffic) and congestion resulted.
Scheme Objectives
1.9
The objectives for the scheme has been derived from the problems identified in the Appraisal
Summary Table (AST) for the scheme and are listed below as follows:


Reduce congestion;
Improve journey time reliability; and

Reduce accidents.
History of the Scheme
1.10
A summary of the key dates in relation to this scheme is shown in Table 1.1.
Table 1.1 - Chronology of the M1 J6a to 10 Widening Scheme
Date
Event
May 1989
First entered road programme.
Aug 1992
Public consultation.
Sept 1994
Publication of Draft Orders.
Autumn 1995
Public Inquiry.
October 1996
Secretary of State’s Decision following Public Inquiry.
July 2003
Entered Programme of Improvements.
December 2003
Orders Confirmed.
December 2004
Secretary of State announcement that this scheme would trial the
1st use of HOV (High Occupancy Vehicle) lanes in England.
March 2006
Construction starts
March 2008
HOV trial dropped in favour of a ‘Controlled Motorway’.
December 2008
Scheme opened to traffic
July 2009
Controlled motorway with Variable Advisory Speed Limits
Introduced.
December 2009
to March 2010
Consultation for proposed Controlled Motorway with Variable
Mandatory Speed Limits.
9
M1 Junctions 6a to 10 Widening One Year After Study
Post Opening Project Evaluation
Purpose of this Report
1.11
The Highways Agency (HA) is responsible for improving the strategic highway network
(motorways and trunk roads) by delivering the Major Schemes programme (formerly
Targeted Programme of Improvements or TPI). At each key decision stage through the
planning process, schemes are subject to a rigorous appraisal process to provide a
justification for the project’s continued development. When submitting a proposal for a major
transport scheme, the Department for Transport (DfT) specifies that an Appraisal Summary
Table (AST) is produced which records the degree to which the five Central Government
NATA objectives for Transport (Environment, Safety, Economy, Accessibility and Integration)
have been achieved. The contents of the AST allow judgements to be made about the
overall value for money of the scheme. The AST for the M1 Junctions 6a to 10 Widening
scheme is presented in Section 8, Table 8.1 of this report.
Overview of POPE
1.12
POPE is undertaken for all Major Schemes. During the planning process, scheme effects are
based on well-informed predictions. However, it is vital to identify the strengths and
weaknesses in the techniques used for appraising schemes so that improvements can be
made in the future. For POPE, this is achieved by comparing information collected before
and after a scheme opens to traffic, with predictions made during the planning process.
Outturn impacts are summarised in an Evaluation Summary Table (EST). The EST
summarises the extent to which the scheme objectives have been achieved and the EST for
the M1 Junction 6a to 10 Widening scheme is included in Section 8, Table 8.2 of this report.
Content of This Report
1.13
The remainder of this report is structured as follows:

Section 2 – Data Collection. The data collected to assist with the scheme evaluation is
presented in this section.

Section 3 – Traffic Analysis. This section examines the impacts of the scheme on
traffic volumes, journey times, and also compares these to the predictions.

Section 4 – The Safety Objective. This section discusses the emerging changes in
accident patterns as a result of the scheme.

Section 5 – The Economy Objective. This section presents a re-evaluation of the
economic costs and benefits attributable to the scheme.

Section 6 – The Environment Objective. A review of the environmental impacts of the
M1 J6a to 10 improvements is undertaken, followed by an evaluation of the mitigation
measures described within the Environmental Statement for the scheme.

Section 7 – The Accessibility and Integration Objectives. A review of how the M1
scheme has affected accessibility for pedestrians and cyclists is presented. Including an
assessment of how well the scheme links with local and regional policy objectives.

Section 8 – Appraisal and Evaluation Summary Tables. This section contains an
overview of the actual scheme impacts compared to those predicted in the original
Appraisal Summary Table (AST).

Section 9 – Conclusions.

Appendix A – Glossary of Terms.

Appendix B – Environmental Information Requested.
10
M1 Junctions 6a to 10 Widening One Year After Study
2.
Data Collection
Introduction
2.1
This section provides a summary of the data sources used to assist this evaluation including:






Traffic Counts;
Journey Times;
Accidents;
Site Visit;
Appraisal Documentation; and
Consultation.
Traffic Counts
2.2
Traffic count data was collected in the area around the location of the scheme in two periods:

Before Construction: 2005; and

2.3
After Opening: 2009
The after opening traffic counts were undertaken in a relatively small ‘window of opportunity’
before construction was due to start on the M1 Junction 10 to 13 Hard Shoulder Running
(HSR) scheme. Construction was originally due to start in November 2009, however, the
timescales have since slipped on this scheme and it’s understood that only offline preparation
works were being undertaken in October 2009. The construction programme of nearby Major
Schemes is shown in Figure 2.1 with the location of these projects in relation to M1 Junction
6a to 10 shown in Figure 2.2.
Figure 2.1 - Timeline of Construction for projects near to M1 J6a to 10 Scheme
11
M1 Junctions 6a to 10 Widening One Year After Study
Figure 2.2 – Construction Status of Schemes in Vicinity of M1 J6a-10 (October 2009)
2.4
The three schemes under construction during the post opening traffic data collection phase
are not considered to have had a notable impact on traffic volumes and patterns on the M1
between Junctions 6a to 10.
2.5
The traffic flow data for this study was derived from a number of sources which are listed
below:



Highways Agency TRADS database;
Hertfordshire County Council (HCC) sites; and
Atkins commissioned surveys.
The locations of the traffic surveys used in this study are shown in Figure 2.3.
Unfortunately, the HA’s TRADS database does not contain traffic data for the following road
links:



Collector Distributor Roads between Junctions 7 and 8;
M1 N/B between junctions 6a and 7; and
M1 N/B between junctions 7 and 8.
The high traffic flows on these routes meant that supplementary surveys were not
commissioned for the purposes of this study. This is because difficult to accurately collect
temporary traffic data on heavily trafficked routes, and also the available traffic data is also
12
M1 Junctions 6a to 10 Widening One Year After Study
considered adequate to provide a sufficient indication of the observed traffic impacts of the
scheme.
Figure 2.3 – Location of Traffic Count Sites
Journey Times
2.6
The HA’s Journey Time Database (JTDB) contains average journey times and speeds for
each 15 minute period throughout the year for each junction to junction link on the HA’s
network. The JTDB has been interrogated to provide before and after data journey times on
the M1 between Junctions 6 and 11 with only the highest quality data selected. The following
time periods were selected to ensure adequate coverage whilst avoiding the construction
period when traffic management and speed reductions would have been in place:

2.7
Before Construction: May 2005 to February 2006; and

After Opening: January 2009 to June 2009 (i.e. immediately prior to controlled
motorway with variable advisory speed limits becoming operational).
It is noted that the post opening period covers less time than the before construction period.
However, this was considered more preferable than including data that may have been
influenced by the operation of the controlled motorway which was not included in the
appraisal of the widening scheme and hence would not be a true ‘like with like’ comparison.
Accidents
2.8
Personal Injury Accident (PIA) data has been provided by Hertfordshire County Council for
the years 2001 to 2010. This data is based on records of PIA’s recorded in the STATS19
13
M1 Junctions 6a to 10 Widening One Year After Study
data collected by the police when attending accidents. Damage only accidents are therefore
not included. It should be noted that the accident data obtained for this study has not yet
been validated by the Department for Transport (DfT). The requirement for up to date
information and site specific data was a consideration in the decision to use unvalidated data
and, as it’s sourced from the local authority, it is considered sufficiently robust for use in this
context.
Site Visit
A site visit was undertaken by a transport planner and environment specialist in July 2010.
Appraisal Documentation
2.9
The following documents produced in relation to the scheme appraisal were obtained for this
study:






2.10
M1 Junctions 6a to 10 Widening – Development & Validation of the Traffic Model
(October 2005);
M1 Junctions 6a to 10 Widening – Design Traffic Flows (March 2006);
M1 Junctions 6a to 10 Widening – Economic Appraisal (March 2006);
M1 Junctions 6a to 10 Widening – Non-Motorised User Context Report (July 2006); and
M1 Junctions 6a to 10 Widening – Detailed Scheme Review (2004)
Appraisal Summary Table (August 2007).
A full list of the information requested and obtained to assist the evaluation of environmental
impacts is shown in Table B.1 on Page 84 at the end of this report.
Consultation
2.11
The following organisations and local authorities have been consulted for the purposes of this
study:

















Environment Agency;
English Heritage;
Natural England;
Hertfordshire County Council;
Central Bedfordshire Council;
St Albans District Council;
Luton Borough Council;
Three Rivers District Council;
Dacorum District Council;
Harpenden Town Council;
Flamstead Parish Council;
Redbourn Parish Council;
St Stephen Parish Council;
Caddington Parsh Council;
Hyde Parish Council;
Slip End Parish Council; and
Markyate Parish Council;
14
M1 Junctions 6a to 10 Widening One Year After Study
3.
Traffic Analysis
Introduction
3.1
In order to assess the traffic impact of the scheme, the following section reports on:





Long term traffic volume trends;
Flow changes on the M1;
Flow changes on the surrounding highway network;
- Local network;
- Wider network;
Changes in journey times;
Comparison of forecast and observed traffic impacts:
- Traffic volumes; and
- Journey times.
Traffic Volume Trends
Historical Traffic Flow Trends on the M1
3.2
Figure 3.1 shows a comparison of the before and after opening traffic flows on the M1
between Junctions 9 and 10. This section was selected because it has the most
comprehensive long term data coverage. Data does not exist for the construction period and
traffic would have been affected by the traffic management anyhow.
Pre Scheme Traffic Flows
Post Scheme Traffic Flows
170000
Construction
Period
165000
Traffic Flow
160000
155000
150000
145000
140000
135000
Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May
2004
2005
2009
2010
Figure 3.1 – Flow Trend on M1 between Junctions 9 and 10 (AWT)
3.3
The key points to note from Figure 3.1 are as follows:


Traffic flows on the M1 are seasonal, with higher traffic flows in the summer months
compared to the winter months; and
The graph shows a visible increase in traffic flows since the scheme opened. However,
this should be considered in the context of potential background traffic growth between
2005 and 2009 which would have occurred regardless of the scheme. This is considered
in more detail in the next section.
15
M1 Junctions 6a to 10 Widening One Year After Study
Background Traffic Changes
3.4
Department for Transport statistics1 indicate that there has been a 1% decrease in vehicle
miles driven in Hertfordshire between 2005 and 2009 (the latest date figures from this source
are available). This figure matches the 1% reduction in England as a whole, resulting from
the economic downturn and resulting recession. However, the statistics show a 0% change
for the South East region.
3.5
Based on the information presented in this section, the traffic flows presented in this report
are as observed, and have not been adjusted to take into account of traffic flow changes
between the before and after opening situation, primarily due to the low percentage change
anticipated based on a review of the statistics.
Traffic Flow Changes on the M1
3.6
Figure 3.2 shows a summary of the before construction (2005) and after opening (2009)
traffic volumes on the M1.
Figure 3.2 – Before and After Opening Traffic Volumes on the M1 (AWT)
1
Road Traffic Statistics for Local Authorities: 1993 to 2009 (Department for Transport).
16
M1 Junctions 6a to 10 Widening One Year After Study
3.7
Figure 3.2 shows that in general traffic flows on the M1 have increased slightly since the
scheme opened. However, this does not show if this increase is a result of completely new
trips, or re-assignment from alternative routes. The causes of the change in traffic flows are
investigated in more detail in the following section.
Traffic Flow Changes on Surrounding Network
Local Network
3.8
Figure 3.3 shows a summary of the before and after traffic volumes on the highway network
in the vicinity of the M1 J6a to 10 scheme.
Figure 3.3 – Before and After Opening Traffic Volumes on the Surrounding Highway Network
3.9
Figure 3.3 shows the following:

There has been a slight decrease in traffic flows on the majority of local roads in the
vicinity of the scheme, suggesting that traffic has re-assigned to the M1 following the
improvement;

In particular, traffic flows has decreased on the A5183 and A1081, the parallel routes to
the east of the M1 between St Albans and Luton. A similar decrease is also observed on
the A5 which suggests that vehicles travelling between the Milton Keynes and St Albans
areas now see the M1 as a more attractive route option.

Traffic flows on the A414 (former M10) have decreased since opening. This could be a
result of the status of the road being downgraded as part of the scheme. Trips travelling
to and from the eastern areas of London may now be more likely to join/leave the M1 at
the M25 junction.
17
M1 Junctions 6a to 10 Widening One Year After Study
3.10
In summary, the observed traffic data from the local highway network shows that the slight
increase in traffic on the M1 (as shown in Figure 3.2 previously) is likely to be a result of reassignment from the local road network.
Wider Network
3.11
The M1 is clearly a major strategic route which carries considerable proportions of long
distance traffic. Therefore a review of the long term traffic trends on the obvious competing
strategic routes has been undertaken to examine if there has been a noticeable impact on
traffic flows on these routes. The most obvious routing alternatives exist on the London to
Birmingham (M40) and London to Doncaster/Sheffield (A1/A1(M)) routes.
3.12
It would be anticipated that a small proportion of traffic may re-route to the M1 following the
improvement. However, a review of the traffic trends on the M40 and A1(M) provides no clear
evidence of changes in traffic flows since the M1 scheme opened. This is more likely to be a
result of two factors:


The level of re-assignment is likely to be very small; and
Other highway network changes (including roadworks and improvements) and
development changes are likely to have had a greater impact on traffic flows.
Changes in Journey Times
Scheme Objective: Reduce Congestion
3.13
Before and after opening weekday journey times have been examined on M1 between
Junctions 6 and 11. The section of motorway immediately north and south of the scheme has
been included in the analysis to determine if the scheme has moved congestion elsewhere.
Figure 3.4 and Figure 3.5 on Page 19 shows a comparison of the northbound and
southbound directions respectively. The following conclusions can be derived from this
analysis:



Post opening journey times are consistently lower in both directions. The average
journey time is now approximately 15 minutes whereas previously the journey time
ranged from 18 minutes to 25 minutes during peak periods;
There is less variability in journey times through the day since the scheme opened
with peak journey times similar to those recorded in the off peak; and
These results provide sufficient evidence to conclude that the scheme has achieved its
objective of reducing congestion.
18
M1 Junctions 6a to 10 Widening One Year After Study
25:00
24:00
23:00
Journey Time (Mins)
22:00
21:00
20:00
19:00
18:00
17:00
16:00
15:00
14:00
Before
13:00
After
12:00
07:00 08:00
08:00 09:00
09:00 10:00
10:00 11:00
11:00 12:00
12:00 13:00
13:00 14:00
14:00 15:00
15:00 16:00
16:00 17:00
17:00 18:00
18:00 19:00
Time
Figure 3.4 - M1 J6 to 11 Northbound Pre and Post Opening Journey Times
25:00
24:00
23:00
Journey Time (Mins)
22:00
21:00
20:00
19:00
18:00
17:00
16:00
15:00
14:00
Before
13:00
After
12:00
07:00 08:00
08:00 09:00
09:00 10:00
10:00 11:00
11:00 12:00
12:00 13:00
13:00 14:00
14:00 15:00
15:00 16:00
16:00 17:00
17:00 18:00
18:00 19:00
Time
Figure 3.5 – M1 J11 to 6 Southbound Pre and Post Opening Journey Times
19
M1 Junctions 6a to 10 Widening One Year After Study
Comparison of Forecast and Observed Traffic
Impacts
3.14
This section contains the following:



A summary of the traffic modelling approach and forecast assumptions;
Forecast vs. observed traffic volumes; and
Forecast vs. observed journey times.
Traffic Modelling Approach and Forecast Assumptions
3.15
Before undertaking an evaluation of the forecast traffic impacts compared to those which
have actually occurred, it is firstly necessary to develop an understanding of how the scheme
has been appraised and the key assumptions used. This may then assist in explaining any
differences between the traffic forecasts and the observed impacts.
Study Area
3.16
The area covered by the traffic model extends from M1 Junction 14 in the north to M1
Junction 6 in the south, and from the A5 in the west to the A6 in the east. It encompasses all
trunk roads and primary routes through the area, as well as other roads that carry significant
volumes of traffic. The urban areas of Milton Keynes, Leighton Buzzard, Luton/Dunstable,
Hemel Hempstead and St Albans are also modelled.
Modelling Approach
3.17
The traffic model which was previously developed for the M1 Junctions 10 to 13 study was
updated and refined to make suitable for assessing the J6a to 10 scheme. The model was
developed using the SATURN software and is fully simulated within the M1 corridor.
3.18
The fourth lane of the widened motorway originally was due to be designated for high
occupancy vehicles (HOV’s) in order to encourage car sharing and thereby reduce traffic
demand in M1 corridor. This proposal was subsequently dropped when the scheme was
being constructed. However, as it was only planned to be a HOV lane on a trial basis, the
potential impacts of the HOV lane have not been considered in the traffic modelling for this
scheme.
Traffic Forecasting
3.19
The following years were modelled:

2008 – Opening Year; and

3.20
3.21
2023 – Design Year (15 years after opening).
Based on HA guidance at the time of the appraisal, the forecast flows for design assessment
purposes were predicted assuming most likely (central) traffic growth to future years. No
allowance was made for any uncertainty or variability in these forecasts (e.g. low or high
traffic growth estimates).
It is not possible to validate the traffic growth assumptions because they were developed
from sector level growth forecasts determined from forecast year cordon matrices extracted
from the LSM (London to South Midlands) model.
20
M1 Junctions 6a to 10 Widening One Year After Study
Forecast vs. Observed Traffic Volumes
3.22
3.23
A number of traffic forecasts were prepared for this scheme and were used for different
elements of the appraisal. A summary of the traffic forecasts and how they are used is
provided below:

Traffic forecasting, economic and safety assessment: M1 Junction 6a to 10
Widening – Design Traffic Flows Report (March 2006);

Noise appraisal: Road Traffic Noise Review (January 2006); and

Air Quality Appraisal: Detailed Scheme Review (May 2004).
Each of the documents presents slightly different traffic forecasts. To maintain consistency, the
actual traffic volumes are compared against those contained in the reports listed above for the
relevant scheme impact (traffic, noise, air quality). Therefore different traffic forecasts are
presented and compared at various stages of this report.
Evaluation of forecast traffic volumes used for traffic, economic and safety
assessment vs. observed traffic volumes
3.24
Forecast traffic volumes (broken down by all vehicles and HGV numbers) for the M1 and
A414 (former M10) are contained are contained in the M1 Junctions 6a to 10 Widening –
Design Traffic Flows Report (March 2006). The appraisal documentation did not contain
without scheme (do nothing) forecasts therefore a comparison with the observed before
opening traffic flows has been possible. Table 3.1 shows a comparison of the forecast and
outturn with scheme (do something) traffic flows on links where observed data is available.
As there is only one year between the forecast (2008) and observed (2009) data, no factoring
has been undertaken to take account of background traffic.
Table 3.1 – Comparison of Forecast and Outturn ‘Do Something’ Traffic Flows
Forecast
Observed
(2008 ADT)
(2009 ADT)
J6a to J7 Southbound
72,200
J8 to J9 Northbound
Difference
%
Difference
81,000
+8,800
+12%
80,800
77,400
-3,300
-4%
J8 to J9 Southbound
68,700
77,900
+9,200
+13%
J9 to J10 Northbound
78,400
78,900
+500
+1%
J9 to J10 Southbound
65,500
78,600
+13,100
+20%
J7 (M1) to J1 (M10) Eastbound
14,700
10,800
-3,900
-36%
J7 (M1) to J1 (M10) Westbound
17,500
11,900
-5,600
-47%
Site
M1
A414
(M10)
3.25
The following points can be noted from the comparison of predicted vs. observed traffic flows
presented in Table 3.1:


Observed northbound traffic volumes are very close to predicted (within 5%); and
Observed southbound traffic flows are considerably higher than predicted on all of
the sections of the M1 where data was available to compare. The Design Traffic Flows
Report does not provide any reasons why the predicted southbound flows are
considerably lower than the northbound flows. A review of the Development and
Validation of the Traffic Model Report shows similar traffic flows in both directions and a
good level of model validation. This shows that it is highly unlikely that the differences
shown in Table 3.1 stem from the base year traffic model.
21
M1 Junctions 6a to 10 Widening One Year After Study


Traffic flows on the A414 are considerably lower than predicted in both directions.
The modelling assumptions used for A414 are not presented in the documentation.
Therefore it is uncertain if the appraisal considered the traffic impacts (if any) of the
downgrading of this route from motorway classification. This could therefore account for
the overestimation of traffic flows on this route.
It is unclear why the appraisal predicted considerable differences in northbound
and southbound flows when the observed data (both recent and historical)
suggests that traffic flows are actually very similar in both directions.
HGV Forecasting
3.26
This section contains a brief analysis of the forecast vs. observed traffic flows with the
scheme in place. This assessment is shown in Table 3.2 for the sites where sufficient data is
available. It should be the noted that the classification of a HGV for the observed results is
any vehicle over 6.6metres in length.
Table 3.2 – Comparison of Forecast and Outturn ‘Do Something’ HGV Traffic Flows
Forecast
Observed
Site
M1
3.27
Difference
%
Difference
(2008 ADT)
(2009 ADT)
Junction 6a to 7 Southbound
10,600
11,200
600
+6%
Junction 8 to 9 Northbound
12,300
10,800
-1,500
-12%
Junction 8 to 9 Southbound
10,600
12,800
2,200
+21%
Junction 9 to 10 Northbound
11,800
12,200
400
+3%
Junction 9 to 10 Southbound
9,900
11,700
1,800
+18%
Table 3.2 shows that the broad patterns evident when comparing predicted vs. observed total
traffic volumes are also evident when comparing HGV numbers.
Forecast vs. Observed Journey Times
3.28
Predicted journey times have not been presented in the appraisal documentation. However,
the Air Quality chapter of the Detailed Scheme Review (DSR) contains forecast speeds for
each of the junction to junction sections with and without the scheme for the year 2007. In the
absence of more comprehensive information, this speed data has been used to provide
indicative predicted journey times. It should however, be noted that the forecast journey
speeds are an average over the day (i.e. 24 hours). Therefore in order to an element of
consistency, average observed journey times over 24 hours in both directions have also been
presented (see Table 3.3).
22
M1 Junctions 6a to 10 Widening One Year After Study
Table 3.3 – Forecast vs. Observed Journey Times
Forecast 2007 (mm:ss)
3.29
M1
Section
Dist
(km)
J6a to J7
Observed (mm:ss)
Do
Minimum
Do
Something
Diff
Before
(2005)
After
(2009)
Diff
4
02:38
02:12
00:26
02:58
02:10
00:49
J7 to J8
1.1
00:54
00:36
00:18
01:00
00:41
00:19
J8 to J9
7.1
05:04
03:54
01:10
05:08
03:53
01:17
J9 to J10
3.7
03:00
02:02
00:58
02:43
02:06
00:38
TOTAL
15.9
11.36
08:44
02:52
11:50
08:50
03:00
Table 3.3 shows that the predicted journey time savings just under three minutes, which
is almost exactly the same as the observed journey time saving. A comparison of the
predicted vs. observed journey times on each junction to junction section also shows a close
match with little difference between the two sets of data.
Key Points from Traffic Analysis Evaluation
Traffic Volume Changes


Traffic flows on the improved section of the M1 have increased slightly since scheme
opening.
There has been a general decrease in traffic flows on the majority of the local roads in
the vicinity of the scheme since opening. This indicates that the slight increase in traffic
observed on the M1 could be a result of re-assignment from these routes.
Journey Times



Post opening journey times are consistently lower in both directions. The average
journey time is now approximately 15 minutes whereas previously the journey time
ranged from 18 minutes up to 25 minutes during peak periods.
There is less variability in journey times since the scheme opened with peak journey
times similar to those recorded in the off peak.
The scheme has therefore achieved its objective of reducing congestion.
Forecasting Accuracy




Observed northbound traffic volumes are very close to predicted indicating a high
degree of forecasting accuracy.
Observed southbound traffic flows are higher than predicted. The reasons for these
forecasting inaccuracies are unclear following a review of the appraisal documentation.
Traffic flows on the A414 (former M10) are considerably lower than forecast, potentially
due to the traffic modelling not taking account of the downgrading of this route following
scheme opening.
The observed journey time saving of three minutes along the extent of the scheme is
almost the same as that forecast.
23
M1 Junctions 6a to 10 Widening One Year After Study
4.
The Safety Objective
Scheme Objective: Improve Safety
Introduction
4.1
This section of the report examines how successful the scheme has been in achieving the
sub-objectives of reducing accidents and improving personal security. This is assessed by
analysing the changes in Personal Injury Accidents (PIA’s) occurring in the five years before
construction and the 14 months after opening of the scheme.
4.2
Analysis of the scheme’s impact on personal security has also been undertaken through use
of observations made during a visit to the site.
Personal Injury Accidents
Study Area
4.3
The forecast benefits for the M1 J6a – 10 widening scheme have been derived from a COBA
(COst Benefit Analysis) model, which gives predicted PIA savings for the opening year and
over the 60 year appraisal period. In order to ensure a like-for-like comparison between the
predicted and observed accidents, the area of analysis used for this study is the same area
covered by the COBA model and is shown in Figure 4.1. This shows that the study area
consisted of the M1 between Junctions 6a to 10 and the associated slip roads only. Therefore
any links which have not been changed by the scheme were not considered in the appraisal.
4.4
Changes in accident over a wider area (that covered by the London to South Midlands (LSM)
model) were also considered in the appraisal but yielded only a small saving compared to the
local area (See Section 5 for more details). As there are likely to be many other factors
influencing the accident rate on surrounding highway network, and the relatively low
predicted saving, the wider area has been excluded from this analysis.
24
M1 Junctions 6a to 10 Widening One Year After Study
Figure 4.1 – Accident Analysis Study Area
25
M1 Junctions 6a to 10 Widening One Year After Study
Evaluation of Accident Numbers and Severity
4.5
An evaluation of before and after opening accident numbers by year for the whole of the
COBA modelled area is shown in Table 4.1.
Table 4.1 – Number of PIA’s by Severity
Accident Severity
Time Period
5 Years Before
(60 months)
14 months After
Average
4.6
4.7
Total
Fatal
Serious
Slight
March 2001 to February 2002
2
24
238
264
March 2002 to February 2003
1
38
268
307
March 2003 to February 2004
2
25
252
279
March 2004 to February 2005
2
32
303
337
March 2005 to February 2006
4
16
287
307
January 2009 to February 2010
1
11
78
90
Annual Saving 1 year after
Annual
Average
299
77
222
The following conclusions can be drawn from Table 4.1:

The number of accidents occurring per year has reduced from an annual average of 299
over the five years before construction, compared to an annual average of 77 after
opening. This represents an annual average saving of 222 accidents, a reduction of
74%.

The number of serious and fatal accidents has also reduced from an average of 29 per
year in the five years before construction, to an average of 10 per year since scheme
opening.
It should be noted however, that the reduction in accident numbers may not be solely
attributable to the scheme, as controlled motorway conditions with variable advisory speed
limits became operational in July 2009. A study on the M25 controlled motorway between
Junctions 15 and 16 indicated that a 10% reduction in accidents had been achieved.2
Assuming that 10% of the accident reduction presented in Table 4.1 is related to the
controlled motorway, this still leaves a considerable reduction which can be attributed to the
widening scheme alone. Therefore the impacts of the controlled motorway on this scheme
should not be overstated until a larger post opening data set becomes available (i.e. at the
Five Years After Opening Stage).
Locations of Accidents
4.8
2
Figure 4.2 shows the before and after accident locations by severity. It should be noted that
‘before’ time period is considerably longer than the ‘after’ time period. However, the diagram
shows that accidents tend to occur along the whole length of scheme with no accident
clusters evident in both the before and after opening situations.
M25 Controlled Motorways Summary Report – Issue 1 (November 2004).
26
M1 Junctions 6a to 10 Widening One Year After Study
Figure 4.2 – Before (60 months) and After (14 months) Opening Accident Locations
27
M1 Junctions 6a to 10 Widening One Year After Study
Evaluation of Casualty Numbers and Severity
The severity level of accidents is determined by the severity of the most badly injured
casualty resulting from the accident. Reducing the number of people killed or seriously
injured (KSI) in road accidents is a Government objective (2010 KSI Casualty Reduction
Target). Table 4.2 therefore presents the casualty statistics corresponding to the accidents
presented earlier.
4.9
Table 4.2 – Number of Casualties by Severity
Accident Severity
Time Period
5 Years Before
(60 months)
14 months After
Average
4.10
Annual
Average
Total
Fatal
Serious
Slight
March 2001 to February 2002
9
61
438
508
March 2002 to February 2003
1
94
470
565
March 2003 to February 2004
9
70
459
538
March 2004 to February 2005
2
71
583
656
March 2005 to February 2006
12
42
531
585
January 2009 to February 2010
2
31
146
179
570
153
417
Annual Saving 1 year after
In the five years before period, there was an annual average of 570 casualties across the
COBA modelled area. In the 16 months after scheme opening, there was an annual average
of 153 casualties representing a decrease of 73% closely matching the decrease in accidents
which shows that the number of casualties per accident has not changed.
Accident Rates on M1 compared to National
Average
4.11
The number of accidents along a length of road together with its AADT can be used to
calculate an accident rate, known as PIA/mvkm. This allows comparisons which take into
account traffic growth and allows comparison with a national average. Table 4.3 shows the
accident rate calculated for the M1 compared to the national average. It should be noted that
the national accident rate for motorways with three and four lanes is the same.
Table 4.3 – Accident Rate on the M1 compared to National Average1
1
4.12
Accidents
Accident
Rate
(PIA/mvkm)
National
Average
PIA/mvkm
17
299 (average of 5
0.309
0.090
17
77
0.080
0.090
Time
Period
Road Type
Route Length
(km)
Before
D3/D4M
After
D4M
Annual
years)
Based on DMRB Vol 13, Section 1, Part 2, Chapter 4, Table 4/1 ‘link only’
Table 4.3 shows that the accident rate before the scheme opened was considerably higher
than the national average. This has now reduced to a quarter of the pre widening accident
rate and is now lower than the national average for this type of road.
28
M1 Junctions 6a to 10 Widening One Year After Study
Accident Significance Testing
4.13
In order to ascertain whether the changes in accident rates observed before and after the
scheme was opened were statistically significant, a statistical test known as a Chi squared
analysis was undertaken which uses the before and after accidents and AADT’s. The
purpose of the Chi squared test is to compare the observed number of accidents with an
expected value if there was no change in the numbers. The test result then establishes
whether the change is significant or likely to have occurred by chance. A summary of the
results of the test are given in Table 4.4.
Table 4.4 – Statistical Significance Test
4.14
Test
Chi ()
square
result
Conclusion
Change in the number of Personal Injury
Accidents
158.9
Reduction is
statistically significant
Table 4.4 shows that the result of the Chi squared test exceeds the critical value of 6.6 for
the 99% confidence level. Therefore it is reasonable to conclude that the change in
accident rate is not a result of chance alone, and that the scheme has had a direct
impact on accident rates.
Predicted vs. Observed Accidents
4.15
This section compares the number of observed accidents discussed earlier with those
predicted to occur. The predictions have been obtained from the COBA model for this
scheme and cover the whole of the COBA modelled area (the AST figures also match the
COBA). For the observed accidents, the Do Minimum figures are based on the annual
average of five years data before the scheme construction started, whilst the Do Something
figures are based on the annual average of 14 months of post widening data.
Table 4.5 – Comparison of Predicted and Observed Accidents
Annual Accidents
Predicted PIA’s
(Opening Year – from
COBA)
Do Minimum (without scheme)
327
Do Something (with scheme)
102
Saving
225
% Change
Observed PIA’s
(Average of 1st 14 months
since opening)
Before Widening
299
After Widening
77
Saving
222
% Change
4.16
-31%
-26%
Table 4.5 shows that the observed change in accidents is very similar to predicted. The
actual difference in accidents is almost exactly the same which indicates that the approach
used to appraise the accident impacts was sufficiently robust. The appraisal used observed
accident data to represent the Do Minimum situation and national average (COBA defaults)
to represent the Do Something scenario.
29
M1 Junctions 6a to 10 Widening One Year After Study
Personal Security
4.17
The aim of this sub-objective is to reflect both changes in security and the likely number of
users affected. In terms of roads, security includes the perception of risk from personal injury,
damage to or theft of vehicles, and theft of property from individuals or from vehicles.
Forecast
4.18
For the Personal Security sub-objective, the AST states:
‘Not really applicable although security will be slightly enhanced by the improved flow for
vehicles thus reducing the frequency of stationary traffic and the opportunity for incidents’
Score: Slight Beneficial.
Evaluation
4.19
The points listed below provide evidence that the forecast personal security impact has been
slight beneficial as expected.



Section 3 of this report has previously shown that traffic flow has improved on the M1,
demonstrated by quicker and more reliable journey times;
Monitoring of the scheme section has improved through the increased provision of CCTV
cameras mostly located on the Controlled Motorway gantries and adjacent to the hard
shoulder. (see Figure 4.3 ); and
Lighting has been improved along the extent of the scheme.
Figure 4.3 – Example of CCTV Cameras and Lighting
4.20
Taking all of these points into account, the impact of the scheme on personal security can
be considered slight beneficial as expected.
30
M1 Junctions 6a to 10 Widening One Year After Study
Key Points from Safety Evaluation
Accident and Casualty Savings
 An annual saving of 77 accidents (and 153 casualties) across the COBA modelled
network compared to the five years before widening indicates that the scheme has been
successful in meeting its objective to reduce accidents.
 There is no evidence of any accident clusters since the scheme opened.
 The observed accident saving is almost exactly the same as predicted which shows that
the forecasting approach was robust in this instance.
 Statistical tests show that the change in accident rate is not a result of chance alone, so
therefore can be attributed to the scheme.
 The accident rate on the M1 is now lower than the national average for this type of road,
compared to an accident rate five times the national average before the scheme
opened.
Personal Security

The impact on personal security is slight beneficial as expected due to improved journey
time reliability and increased CCTV provision.
31
M1 Junctions 6a to 10 Widening One Year After Study
4.21
5.
The Economy Objective
Introduction
5.1
This section provides an indication of the monetary benefits of the scheme, based on
information collected before and one year after widening, and compares these to the forecast
economic impacts over the 60 year appraisal period. Outturn costs of the scheme (to date)
have also been compared with those predicted in the appraisal period. The remainder of this
section is structured as follows:






Predicted Benefits;
Outturn Benefits
Scheme Costs;
Benefit Cost Ratio;
Journey Time Reliability; and
Wider Economic Impacts.
Predicted Benefits
5.2
A summary of the predicted scheme impacts from the Economic Assessment Report is
shown in Table 5.1. This shows that over the 60 year appraisal period the scheme was
predicted to generate in excess of £2billion benefits with the vast majority arising from
reduced journey times and accidents – as would be expected from this type of project. Table
5.1 also provides a summary of the benefits which will be considered in this evaluation, and
those which have been excluded (i.e. assumed same as forecast).
Table 5.1 – Summary of the Predicted Benefits and Reasons for Evaluation/Non Evaluation
Benefit
Stream
Predicted
Benefit
Evaluation
£m
%
£1,235.7m
62%
Safety
£773.4m
39%
Vehicle
Operating
Costs (VOC’s)
£53.8m
3%
Construction
Delay
-£137.8m
-7%
Maintenance
Delay
£78.6m
4%
£2.004.4m
100%
Journey Times
Total
/
Reasons


Represents a considerable proportion of the overall
scheme benefits; and
Relatively straightforward to measure outturn impacts.
Represents a considerable proportion of the overall
scheme benefits; and
Relatively straightforward to measure outturn impacts.
Small proportion of overall scheme benefits; and
POPE approaches to calculating outturn VOC impacts
not sufficient to accurately re-estimate benefits of this
low magnitude.
Not within the remit of POPE;
Small proportion of the overall scheme impacts;
Almost impossible to measure outturn impacts.
Not within the remit of POPE;
Small proportion of the overall scheme impacts;
Almost impossible to measure outturn impacts.



32
M1 Junctions 6a to 10 Widening One Year After Study
Outturn Benefits
5.3
This section considers the two main impacts predicted to arise from the scheme (journey
times and accident reductions), and uses observed data to re-forecast the monetary benefits.
Journey Time Savings
Forecast
5.4
By relieving congestion on the existing motorway and adjacent roads, the scheme was
predicted to generate considerable time savings, estimated to be in excess of £1billion over
the 60 year appraisal period. This prediction is based on weekday flows only and therefore
ignores any benefits that may occur at weekends.
Evaluation Methodology
5.5
The basis of the POPE methodology (in terms of vehicle hour savings) is a comparison of
changes in predicted vehicle hours (using journey times and traffic flows) and relating this to
the equivalent before and after widening using observed journey times and traffic flows. As
such this method is most commonly applied to schemes that have been appraised using the
COBA software. However, the vehicle hour savings for the M1 Junction 6a to 10 scheme
were appraised using TUBA software which is currently recommended by the DfT. TUBA is
matrix based (unlike COBA which is link based) so the TUBA model cannot be used as the
basis on a post opening evaluation; hence the POPE methodology is not suitable for the OYA
evaluation of these schemes.
5.6
As an alternative approach, the journey time benefits for these schemes have been evaluated
using a Project Appraisal Report (PAR) approach, typically adopted by the HA for the
appraisal of smaller schemes3. This evaluation is therefore subject to a number of caveats
and assumptions as listed below:



The evaluation only includes journey time savings on the M1, and not the wider network.
However, for a widening scheme with limited traffic reassignment (as shown earlier in
Section 5) it is anticipated that the vast majority of the benefits will occur on the M1.
However, the outturn journey time benefits presented later in this section are likely to
represent a slight underestimate due to the local roads being omitted.
The PAR method provides capitalisation factors which depend only on the road type and
forecast growth rate whereas modelling tools used for the appraisal consider the
complexity of how traffic growth would affect future traffic behaviour in detail. For this
scheme, future forecasts will be influenced by timing and severity of forecast congestion
with or without the scheme.
The impact of the Controlled Motorway on M1 is omitted (which therefore represents a
like with like comparison with the appraisal).
Evaluation
5.7
3
The PAR method of calculating the TEE journey time benefits is based on the vehicle hours
saved in the first year, monetised by using a Value of Time (VOT) then converted to a
forecast for the whole appraisal period using capitalisation. Values for the VOT for an
average vehicle per hour and capitalisation factors are specified in the PAR guidance.
PAR Guidance Project Appraisal Report Guidance Notes Version 5.0
33
M1 Junctions 6a to 10 Widening One Year After Study
5.8
It is not possible to use TUBA outputs to create a comparable forecast based on the impacts
on the same corridor, as TUBA is matrix based and its output does not give any breakdown
of the impacts by link or area. Therefore, for the evaluation of the selected links, vehicle
hours saved in the opening year were calculated using the observed traffic flows and journey
times described in the traffic section extrapolated to a full year based on the AM, IP and PM
weekday time periods as used in the appraisal. The vehicle hour calculation was carried out
on the M1 between Junctions 6a and 10 (i.e. scheme section only).
5.9
The calculation of the vehicle-time saving is shown below in Table 5.2 and includes the
results for 0% traffic growth over 60 years (low case), and NRTF97 traffic growth (high case)
scenarios.
Table 5.2 - Journey Time Saving and Monetary Benefit (2002 prices)
Scenario
Parameter
0% Traffic
Growth
NRTF Traffic
Growth
(Low Case)
(High Case)
Vehicle Hours Saved in Opening Year
1.8million
Value Of Time per hour at 2002 market prices
£12.66
Annual Time Saving at 2002 prices
£22.8m
60-Year Capitalisation Factor
60-Year Time Saving
39.6
49.9
£901.3m
£1,136.8m
Discount factor
5.11
60-Year Time Saving discounted to 2002
£733.7m
£925.3m
60-Year Time Saving discounted to 2002 (in market
prices)
£887.0m
£1,118.7m
Journey Time Benefits
Benefit
Table 5.2 shows that the re-evaluated 60-year time
benefit in market prices, based on observed traffic
conditions one year after opening is between £887m
and £1,118m, compared to a forecast benefit of
£1,235. An illustration of the how the predicted and
observed journey time benefits compare is also shown
opposite (not to scale).
Forecast
Wide Area
The main points to note are as follows:


The outturn journey time benefit is a conservative
estimate based on the M1 only, whilst the
appraisal covered a number of other roads in the
wider area. This is likely to be the main reason for
the lower than forecast results.
The effects of the recession would not have been
considered in the forecast, hence the inclusion of
a range of results with the NRTF growth
representing a high case and no traffic growth
representing a low case.
Outturn (NRTF
Growth)
Local Area
Outturn (No
Growth)
Increasing
5.10
0.814
34
M1 Junctions 6a to 10 Widening One Year After Study


The evaluation shows that the scheme still generates considerable monetary journey
time benefits despite the limited study area and assumption of no traffic growth
throughout the appraisal period.
Given that the appraisal period lasts for 60 years and effects of the recession are likely to
reduce over time (leading to increases in traffic), the results associated with the NRTF
growth have been taken forward to recalculate the BCR later in this section.
Accident Savings
5.12
When appraising trunk road schemes, the economic impact of changes in safety are
calculated by assigning monetary benefits to the reduction in the number and severity of
personal injury accidents over the appraisal period.
Forecast
5.13
The forecast accident savings for this scheme were derived using a two tier methodology
described below as follows:


Local Area - The DfT’s COBA program has been used to estimate the number of
accidents and casualties by severity that would be saved by the scheme over the 60
year appraisal period (2008-2067). These savings have then been converted by the
program to 2002 monetary values (discounted to 2002). The COBA model covered the
M1 between Junctions 6a and 10 including the slip roads (and the Collector-Distributor
Roads in the do something scenario).
The results of the COBA accident analysis showed that the M1 widening scheme would
reduce the number of accidents between M1 Junctions 6a and 10 by 16,600 during the
60 year appraisal period, including a reduction in fatalities of 253. This equates to
accident cost savings of £722.9m.
Wider Area - Accident cost savings outside of the immediate vicinity of the scheme were
calculated based on traffic forecasts from the London to South Midlands (LSM) traffic
model and resulted in further accident cost savings of £50.5m. The forecast accident
reduction which equates to this monetary value has not been presented in the Economic
Assessment Report.
5.14
Overall, the total accident savings resulting from the scheme were therefore forecast to be
£773.4m.
5.15
The forecast accident benefits are so high because the observed accident rate on the M1
from 2001 to 2004 was used to represent the Do Minimum situation. These figures are
significantly higher than the national average accident rates assumed in the do something
scenario with the scheme in place. This approach is considered robust as it is in line with the
guidance available at the time of the appraisal and yielded results which were very similar to
the outturn evaluation.
Evaluation Methodology
5.16
The POPE method of evaluating the economic value of benefits arising from safety
improvements is based upon comparing the observed and forecast accident saving in the
opening year combined with the assumption that the observed safety impact in the opening
year can be taken to be indicative of the trend for the whole appraisal period. Based on this
assumption, comparing the forecast opening year accident saving with the observed saving
in the opening year enables the calculation of a 60 year monetised benefit. In order for this
analysis to be undertaken, it was necessary to use the COBA results for the predicted
accidents and not those presented in the Economic Assessment Report. This was because
the forecast opening year accident numbers are required which were not reported in the
latter.
35
M1 Junctions 6a to 10 Widening One Year After Study
5.17
The accidents occurring in the wider area have been assumed to be the same as predicted
for the following reasons:



The vast majority of the predicted accident savings are derived from improvements to the
M1 itself – as would be expected;
Section 3 of this report identified slight traffic reductions on surrounding roads, which
generally results in a corresponding reduction in accidents. This serves to verify the
modest accident savings predicted over the wider area; and
The size of the model of the LSM modelled area has not been described in the
documents, however, it is likely to cover a considerable geographical area. If observed
accidents were collected over the same area then it’s likely that other external factors
may have influenced the frequency of accidents (e.g. other highway schemes).
Evaluation
5.18
The evaluation of the safety benefits is shown in Table 5.3. This calculation is based on the
presumption that the forecast ratio of the number of accidents saved in the opening year to
the forecast 60 year benefit (shown in (c) in the table) can be used to generate a re-forecast
economic benefit (e) based on the observed saving of accidents (d).
Table 5.3 – Predicted vs. Outturn Safety Benefits
Calculation
Approach
Local
Area
Wider Area
Forecast number of accidents
saved in opening year
(a)
225
Not Available
Forecast benefit over 60
years
(b)
£722.9m
£50.5m
Approximate 60 year benefit
per opening year accident
saved
(c) = (b) /
(a)
£3.21m
Not Available
Observed
Outturn number of accidents
saved in opening year
(d)
222
Not considered due to
reasons stated in
Paragraph 5.17
POPE ReForecast
Re-forecast 60 year accident
benefit
(e) = (d) x
(c)
£712.6m
£50.5m
COBA
Forecast
5.19
This POPE evaluation of the re-forecast 60 year benefits indicates an outturn safety benefit of
£763.1m based on the following assumptions:



5.20
The accident pattern observed in the opening year is typical of the impact in the longer
term;
The original modelled assumptions hold true; and
The impact of the Controlled Motorway with mandatory speed limits, which is expected to
be in operation later this year and hence for the majority of the 360 years covered in this
outturn calculation, is not included in this evaluation, but nor was it considered at the
appraisal.
The POPE re-forecast shows that the accident benefits are similar to predicted (within 2%).
However, the analysis has only utilised one year of post widening data. An analysis of the
accident impacts should be possible in greater detail when undertaking the Five Years After
Study.
36
M1 Junctions 6a to 10 Widening One Year After Study
Scheme Costs
5.21
This section compares the forecast cost of the scheme with the outturn cost as of 2010 as
shown in Table 5.4. The last published predicted costs are contained in the Economic
Appraisal (April 2006). The outturn spend profile for this scheme has been obtained for the
purpose of this study from the HA Regional Finance Manager (in March 2010). The as-spent
figures for the period 2000 – 2009 have been converted to 2002 prices. This figure can then
be compared with the forecast cost on a comparable basis. It should also be noted that the
outturn costs at this stage may not include all of the Part 1 Land Compensation Claims which
can take many years to process. A more valid comparison of the scheme costs is therefore
possible at the Five Years After Opening stage.
Table 5.4 – Forecast vs. Outturn Scheme Costs
Cost Element
Costs in £million 2002 prices
Forecast
Outturn
Construction
Supervision
£212.4m
£268.6m
Preparation
Land
£10.5m
Controlled Motorway
£5.2m
Renewal of Roads
E & C OFT* Provision: Main works
Not specified in
Economic
Assessment Report.
E & C OFT* Provision: Controlled
Motorway
TOTAL
£5m
£15.5m
£2.6m
£268.6m
£251.2m
* E & C OFT = Engineering and Construction Open for Traffic. I.e. costs incurred after opening to finalise scheme
elements.
5.22
The main points to be noted from Table 5.4 are as follows:

Outturn scheme costs are lower than forecast despite the additional controlled motorway
elements that were not considered at the time of the forecast investment cost estimate;
and

It should be noted, however, that claims under Part 1 of the Land Compensation Act take
time to materialise so a more accurate reflection of the outturn scheme costs will be
available when the Five Years After Study is undertaken.
Benefit Cost Ratio (BCR)
5.23
The BCR is used as an indicator of the overall value for money of the scheme. For the
purpose of evaluating the BCR the forecast and outturn costs have been discounted to 2002
using the now standard discount rate of 3.5% and converted to market prices. The BCR is
used as a summary of the overall value for money of a scheme. Using the predicted
economic benefits (PVB) and costs (PVC) from the Economic Appraisal, and the outturn reforecast PVB and PVC detailed earlier in this chapter, the BCR’s can be compared as shown
in Table 5.5.
37
M1 Junctions 6a to 10 Widening One Year After Study
Table 5.5 - Forecast vs. Outturn Re-forecast Benefit Cost Ratio
Forecast
Outturn
£1,235.7m
£1,118.7m
£773.4m
£763.1m
-£4.8m
-£4.8m*4
£2,004.3m
£1,877.0m
Present Value of Costs (PVC)5
£290.0m
£275.4
BCR (including safety benefits)
6.9
6.8
BCR (excluding safety benefits)
4.2
4.0
Journey Times
Present
Value of
Benefits
(PVB)
Safety
Other Benefits (VOC’s, Construction
delay, Maintenance delay)
Total PVB
* Same as forecast assumed due to low magnitude of benefits.
5.24
Table 5.5 shows that the outturn BCR is slightly lower than forecast mainly due to lower than
forecast journey time savings (although this is a conservative estimate) and slightly lower
than accident savings. However, the re-calculated BCR’s (both with and without accident
benefits included) still show that at this stage the scheme is delivering value for money.
5.25
It should be noted that the BCR presented in this section does not consider non-monetised
impacts. In NATA assessments, the impact on environmental, accessibility, and integration
objectives must be assessed but these are not monetised. The evaluation of these objectives
is covered in later sections of this report.
Journey Time Reliability
Scheme Objective: Improve Journey Time Reliability
Forecast
5.26
The 2007 AST states:
‘Based on preliminary INCA results, additional benefits in excess of £500m may be accrued
to the scheme due to improved travel time reliability and the reduction in incidents.’
Evaluation
5.27
The INCA (Incident Cost Benefit Assessment) model for this scheme was not available to the
evaluation team, and commentary relating to journey time reliability is absent from both the
TFR and the EAR. The evaluation therefore focuses on two alternative approaches:


Standard deviation of journey times; and
Analysis of observed incident data.
4
Same as forecast due to low magnitude of benefits
The forecast PVC presented here includes the forecast indirect tax revenues during construction, maintenance and operation which
represents approximately 5% of the PVC. The outturn PVC has included the same indirect tax impact.
5
38
M1 Junctions 6a to 10 Widening One Year After Study
Standard Deviation of Journey Times
5.28
Reliability is concerned with variability in journey times. Therefore a proxy for reliability can be
obtained by examining the variation of journey times using the data in the JTDB (used in
Section 3 of this study). The metric used is standard deviation of journey times from the mean
time for each time period in the before and after widening periods. The larger the deviation
from the mean journey time, the greater the unreliability. The difference in the standard
deviation in the before and after periods is shown graphically in Figure 5.1 and Figure 5.2 for
journey times on scheme section of the M1 in the northbound and southbound directions
respectively.
200
Before
180
After
Seconds
160
140
120
100
80
60
07:00 - 08:00 - 09:00 - 10:00 - 11:00 - 12:00 - 13:00 - 14:00 - 15:00 - 16:00 - 17:00 - 18:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00
Time
Figure 5.1 – Standard Deviation of M1 Northbound Journey Times (J6a to 10)
200
Before
180
After
Seconds
160
140
120
100
80
60
07:00 - 08:00 - 09:00 - 10:00 - 11:00 - 12:00 - 13:00 - 14:00 - 15:00 - 16:00 - 17:00 - 18:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00
Time
Figure 5.2 – Standard Deviation of M1 Southbound Journey Times (J6a to 10)
5.29
Figure 5.1 and Figure 5.2 show that journey times are now more consistent throughout day
and the standard deviation of journey times on the improved section of the M1 has reduced
since the scheme opened. This provides an indication that journey time reliability has
improved as a result of the scheme.
Wider Economic Impacts
Forecast
5.30
The AST states:
39
M1 Junctions 6a to 10 Widening One Year After Study
‘No issues relating to designated regeneration areas’.
Evaluation
5.31
Wider economic impacts were not considered as part of the appraisal, however, it’s clear that
the scheme has had a considerable impact on both the surrounding local and regional
economy.
5.32
The M1 motorway has a key function in providing strategic connectivity between London and
the Midlands and the North for passengers and freight. This report has already shown that
the scheme has increased capacity, improved journey times and reliability, and improved
safety. Although the impacts cannot be quantified, it can therefore be inferred that the
scheme has facilitated wider economic benefits.
5.33
The Milton Keynes South Midlands (MKSM) is one of the largest growth areas established in
2004 as part of the Government’s Sustainable Communities Plan. A key facilitator in
delivering increased numbers of housing and jobs in the area is a transport infrastructure that
can cope with these growth plans. The M1 Junction 6a to 10 widening scheme (along with
adjacent improvements to on the stretch between J10 and 13 – currently under construction)
will provide increased capacity to enable the growth plans to be realised whilst maintaining
and improving the performance levels of the M1.
Key Points from Economy Evaluation
Outturn Costs and Benefits


The re-forecast safety benefits are almost exactly the same as predicted (although
evaluation was undertaken using only one year’s worth of observed data).
The outturn scheme costs are lower than forecast. This is despite the outturn figures
including elements of controlled motorway which were not considered in the forecast.
Benefit Cost Ratio

The outturn BCR is slightly lower than forecast due lower than predicted journey times
(although it is recognised this is a conservative estimate) and fewer accident savings.
However, the scheme still represents good value for money.
Journey Time Reliability

An analysis of the standard deviation of before and after journey times indicates that
journey time reliability has improved as a result of the increased capacity provided by
the scheme.
Wider Economic Impacts

The scheme has contributed to the growth aspirations of the MKSM area by providing
additional capacity and improved journey times on the main strategic highway through
the area.
40
M1 Junctions 6a to 10 Widening: One Year After study
6.
The Environment Objective
Introduction
6.1
In relation to environment, the Environmental Statement Non-Technical Summary (NTS)
stated that:
“…Mitigation measures form an integral part of the proposals. The main measures include
extensive environmental screening, either in the form of earth mounding, screen fencing or
noise barriers. This would help protect sensitive locations from the scheme effects
particularly visual and/or noise intrusion. Planting both beside and away from the motorway
would be used to give relief to areas exposed to the more intrusive sections of the road.”
Data Collection
6.2
As explained earlier in this report, the widening scheme was originally proposed in the early
1990s and a Public Inquiry held in 1995, however the scheme was then put on hold until
2004. Although a full copy of the 1994 Environmental Statement has not been available for
this evaluation, the Non-Technical Summary was available and has been used. The scheme
was updated in 2004 including environmental information, as reported in the Design Scheme
Review which has also been used in this evaluation.
6.3
The following documents have been used in the compilation of this section of the report:

Appraisal Summary Table (AST), August 2007;

M1 Junction 6A (M25 Interface) to Junction 10 (South of Luton) Explanation of NonTechnical Summary – September 1994;

Detailed Scheme Review (DSR), June 2004;

Public Inquiry Commitments, November 1996;

Environmental Status Report, November 1995;

Ecology Design Phase 1b, November 2005;

Landscape Management Plan (Five Year Aftercare Period Post Construction 2009 –
2013), April 2009;

Ecological Management Plan (Five Year Aftercare Period Post Construction 2009 –
2013), March 2009;

Ecological Monitoring Post Construction Interim Summary Results, October 2009;

Ecological Monitoring Report 2009, June 2010;

Road Traffic Noise Review (RTNR), January 2006;

Archaeological Design Part 2: Mitigation Strategy, Atkins September 2006;

Archaeological Post-excavation Assessment Report, Oxford Archaeology, January 2008
(draft unpublished);

Maintenance and Repair Strategy Statement, September 2008;

Non-Motorised User Context Report (July 2006);

Scheme newsletters and publicity information from HA web page;

As Built drawings for Landscape and Ecology Design; and

M1 6a-10 Widening Lighting Design, Junction 9 Friars Wash Underpass Lighting Study
Report, November 2005.
A full list of the background information requested and received to help with the
compilation of this report is included in Appendix B.
41
M1 Junctions 6a to 10 Widening: One Year After study
Site Inspection
6.4
A site visit was undertaken in August 2010.
Consultations
6.5
Table 6.1 lists the organisations contacted regarding their views on the impacts they perceive
the road scheme has had on the environment, and whether they feel that the mitigation
measures implemented have been effective.
Table 6.1 - Summary of Environmental Consultation Responses
Organisation
Field of Interest
Comments
Natural England
Biodiversity & Landscape
No comments
English Heritage
Heritage
As expected
Environment Agency
Water
Surface water drainage systems
and balancing ponds carried out
to high standard.
Water / air quality / noise
No response
Heritage
Some concerns
Public Rights of Way
No response
Heritage
Several concerns
Biodiversity
No response
Landscape
No comments
Public Rights of Way
Some concerns
Heritage
No comments
Biodiversity
No comments
Landscape
Implemented as expected
Biodiversity
Implemented as expected
Water / air quality / noise
No comments
Landscape
No response
Water / air quality / noise
No comments
Landscape/noise
Loss of green landscape noted.
Comments from residents that
new road surface appears to
generate less noise.
Water / air quality / noise
No comments on water issues.
No
noise
assessments
undertaken
and
no
noise
complaints.
No air quality
monitoring undertaken in the
vicinity.
General
Excessive lighting at Junction 9
tunnel. Rubbish at Junction 9
roundabout. Size of signage at
Junction 9 too large for rural
location.
St Albans District Council
Hertfordshire County Council
Central Bedfordshire Council
Luton Borough Council
Three Rivers District Council
Dacorum District Council
Flamstead Parish Council
42
M1 Junctions 6a to 10 Widening: One Year After study
Organisation
Field of Interest
Comments
Redbourn Parish Council
General
No response
St Stephen Parish Council
General
No response
Caddington Parish Council
General
No response
Hyde Parish Council
General
No response
General
Insufficient acoustic fencing at
Pepperstock Bridge. Increase in
noise following removal of mature
trees.
Drainage structure on
Church Road has industrial
appearance.
View from M1
impaired by long stretches of
acoustic barriers. Lighting under
Church
Road
bridge
poor
compared to lighting at Junction
9. Concerns that any increase in
traffic will affect air quality.
Markyate Parish Council
General
Major impact on landscape
character, more planting needed.
Lighting at Junction 9 tunnel overengineered. Concern at further
marginalisation of River Ver due
to widened structure.
Water
bodies at Junctions 9 and 10 not
camouflaged. PROWs retained
as expected. No increases in
noise or pollution noticed.
Harpenden
General
No comments on environmental
topics
Wildlife Trust
Biodiversity
No comments
Slip End Parish Council
6.6
The Highways Agency Part 1 Team has been contacted regarding Part 1 claims and it is
understood that it is too early in the claims period to say how many will be successful and
therefore suggested that this information should be made available for the FYA report.
6.7
Animal mortality figures have been provided by the MAC, and these are included in the
biodiversity section.
Traffic Forecasts Evaluation
6.8
Three of the environmental sub-objectives (noise, local air quality and greenhouse gases) are
directly related to traffic flows. No new noise or air quality surveys are undertaken for POPE
and an assumption is made that if traffic is as expected then it is likely that local noise and air
quality are as expected.
6.9
The NTS (1994) stated that the M1, at the time, carried on average more than 120,000 vpd
with up to 20% of this traffic consisting of HGVs. The motorway was very heavily used and
subject to congestion, which it was said, would be relieved by the proposed improvements.
6.10
By January 2004 a pre-scheme newsletter noted that traffic had increased to 160,00 vpd with
long delays at peak times.
6.11
As noted in the Traffic section of this report, a number of traffic forecasts were prepared for
this scheme and were used for different elements of the appraisal.
43
M1 Junctions 6a to 10 Widening: One Year After study
Each of the documents presents slightly different traffic forecasts. For this environment section,
the actual traffic volumes after opening are compared against those forecast in the Road Traffic
Noise Review (January 2006) for the noise evaluation and for air quality the Detailed Scheme
Review (May 2004). )..
Noise
Forecast Impacts AST and ES
6.12
The AST stated that increases in noise levels of up to 3dB would be experienced at 10
properties and that 408 properties would benefit by decreases of up to 15dB. On the basis of
the assessment, no additional means of mitigation were considered necessary other than
those that had already been incorporated into the scheme proposals. Overall the assessment
forecast that 34 more people would benefit from the scheme.
6.13
The Non-Technical Summary (NTS) noted that noise reduction proposals would comprise a
combination of earth mounding where sufficient land was available and / or noise fencing to
provide a 3m high barrier alongside the motorway. It was estimated that noise 15 years after
scheme completion would generally be no greater than existing although a few properties
would have a small increase. Specific noise mitigation would be;

Junctions 6a to 7 – none mentioned;

Junctions 7 to 8 – earth mounding and screen fencing, including to the east of the new
carriageway where fencing at Westwick Hall was expected to lower noise levels in the
opening year by around 3dB compared to if no environmental barriers were used;

Junction 8 to The Aubreys – none mentioned;

The Aubreys to Junction 9 – a combination of 3m high earth mounding and noise fencing
(where it was necessary to restrict land take) would be expected to reduce noise levels for
properties closer to the motorway so that at 15 years after scheme completion noise would
be no greater than existing levels;

Junctions 9 to 10 – none mentioned.
Updates since the ES
6.14
The DSR stated that the majority of properties within 300m of the relevant sections of the M1
would benefit from a reduction in noise levels with the improvements in place. Whilst noise
levels might increase at a small number of properties, such increases would be imperceptible.
The same would also be true for vibration. Overall, the DSR stated that the proposed
improvements would result in a neutral to moderate beneficial impact on the surrounding
countryside, such that no further mitigation measures, beyond those already proposed, were
considered necessary.
6.15
The RTNR stated that the proposed scheme included the provision of environmental noise
barriers and earth bunds to mitigate noise, and that the location and dimensions of these
were as stated at the 1995 Public Inquiry (PI). The RTNR also noted that it was expected
that no houses would qualify for noise insulation compared to about 19 indicated at the 1995
PI. However, it was noted that this would need to be reviewed if there were found to be
increases in forecast traffic flows or speeds up to the end of the appeals period prescribed in
the Noise Insulation Regulations. The overall effect of noise from the proposed scheme,
taking into account the mitigation measures, was expected to be an improvement upon the
impacts shown at the 1995 PI and in the figures given in the DSR.
44
M1 Junctions 6a to 10 Widening: One Year After study
Consultation on Noise
6.16
Dacorum District Council commented that some residents had said that the new road surface
had been beneficial in terms of generating less noise. No noise assessments have been
carried out and no complaints of noise nuisance received.
6.17
Slip End Parish Council commented that the wooden noise barriers had not been extended to
their satisfaction southwards beyond Pepperstock Bridge. The properties in Pepsal End Lane
are subject to extra noise and visual detraction because the original mature tree cover has
been removed. POPE notes that the original mature tree screening has been removed in this
location, but that acoustic barriers have been erected as stated in the RTNR.
6.18
Markyate Parish Council commented that they had not noticed any increase in noise.
Evaluation of Noise
6.19
It should be noted that the findings of the RTNR were based on forecast traffic flow figures
produced in October 2005, before the final traffic flow forecast figures used elsewhere in this
report were available. ..
Table 6.2 – Road Traffic Noise Review Traffic Flows Forecast vs. Observed Traffic Flows
RTNR Forecast
ADT
Observed ADT
2008
2009
Junction 6a to
7 Southbound
75,800
Junction 8 to 9
Northbound
Site
Difference
% Difference
81,000
+5,200
+9%
84,000
77,400
-6,600
-9%
Junction 8 to 9
Southbound
71,300
77,900
+6,600
+9%
Junction 9 to
10 Northbound
81,400
78,900
-2,500
-10%
Junction 9 to
10 Southbound
68,000
78,600
+10,600
+9%
6.20
Table 6.2 shows a comparison of the forecast and outturn with scheme (do something) traffic
flows on links where observed data is available. As there are only two years between the
forecast (2007) and observed (2009) data, no factoring has been undertaken. The data
indicates that traffic flows on the M1 are within the POPE methodology parameters of +25%
or -20% of predictions, and it is likely that, based on traffic flows, the local noise climate due
to traffic is as expected. No noise data was included in the RTNR for the A414 or distributor
roads to allow comparisons to be made. However the Traffic section of this report indicates
that there has been a general decrease in traffic on the majority of local roads in the vicinity of
the scheme since opening.
6.21
It was stated at the PI that a porous asphalt road surface would be used that is designed to
reduce noise by up to 3.5dB compared to a conventional hot rolled asphalt road. Since that
time, it is understood that instead of porous asphalt an alternative low noise road surface
product has been used. The RSI value of the road surface has not been advised to POPE
and its effectiveness cannot be confirmed. It is understood that no post opening noise
surveys have been undertaken. Based on observations undertaken during the site visit,
mounding and acoustic barriers to a height of 3m have been constructed as stated in the
RTNR. The performance specification of the barriers has not been confirmed to POPE.
45
M1 Junctions 6a to 10 Widening: One Year After study
6.22
The feedback from Slip End Parish Council regarding increased noise due to the loss of mature
trees cannot be confirmed as no post opening monitoring has been undertaken, and noise barriers
have been erected as expected.
6.23
A summary of the evaluation is shown in Table 6.33.
Table 6.3 - Summary of Noise Impact
Origin of
Assessment
AST
(Forecast)
Summary of Effects
Assessment
Increases in noise levels of up to 3dB would be experienced
at 10 properties. The assessment has also found that 408
properties would gain decreases of up to 15dB On the basis
of the assessment, no additional means of mitigation are
considered necessary other than those that have already
been incorporated into the scheme proposals.
Population
Annoyed Do
Something
minus Do
Minimum -34.
Estimated Population Annoyed Do Minimum:191
Estimated Population Annoyed Do something:157
EST
(OYA
evaluation)
Mitigation measures appear to have been implemented as
expected. Based on traffic flows, which are within +25%` / 20% of predictions, it is likely that the local noise climate
based on traffic is as expected.
Likely to be
as expected.
Air Quality
Forecast Impacts AST and ES
6.24
The AST stated that a negligible deterioration in local air quality was expected with the
scheme in place. Changes in concentrations at properties within 200 metres of the scheme
would be well below the significance criteria for nitrogen dioxide (NO2) and particulate matter
(PM10) and were unlikely to be measurable. Changes in air quality were expected due to the
increase in traffic volume and speed. .
6.25
The NTS noted that air pollution levels were elevated along the M1 carriageway but
decreased rapidly with increasing distances from the motorway. NO2 might exceed EC
Directive limits at or above the M1 centreline but not beyond the motorway boundary. The
decrease in congestion as a result of the scheme and improvements in vehicle technology
were expected to lead to a decrease in emissions. Levels of NO2 in 15 years time were
expected to be broadly similar to existing levels despite the expected increase in traffic flows.
The overall effect of the scheme would be low to moderately beneficial in the short to medium
term. The long term effect would be adverse but of low to negligible significance.
Updates since the ES
6.26
The DSR stated that the proposed widening would lead to an increase in the number of
properties that would fall within 200m of the road, and that there would be moderate adverse
increases in annual average NO2 concentrations at a number of locations in the vicinity of the
motorway. No baseline figures for HGVs was included in the DSR.
Consultation on Air Quality
6.27
Dacorum District Council commented that no air quality monitoring is undertaken in the
immediate vicinity as there are no sensitive receptors nearby.
6.28
Slip End Parish Council commented that it considered that any increase in traffic will affect air
quality.
46
M1 Junctions 6a to 10 Widening: One Year After study
6.29
Markyate Parish Council commented that it had not noticed any increase in pollution.
Evaluation of Air Quality
Table 6.4 – Detailed Scheme Review Air Quality Traffic Flows Forecast vs. Observed Traffic Flows
Forecast (2
way) DSR
Site
2007 ADT
Observed (2
way) 2009 ADT
Difference
% Difference
Junction 8 to 9
82,500
77,650
-4,850
-9%
Junction 9 to 10
78,200
78,750
+550
+1%
6.30
Table 6.4 shows a comparison of the forecast and outturn with scheme (do something) 2 way
traffic flows on links on the M1 where observed data is available. As there are only two years
between the forecast (2007) and observed (2009) data, no factoring has been undertaken.
No data was available for local roads or for speed. The data available indicates that traffic
flows on the M1 are within +/-10% of predictions, and based on POPE methodology it is likely
that the local air quality due to traffic is as expected.
6.31
A summary of the evaluation is shown in Table 6.55.
Table 6.5 - Summary of Air Quality impacts
Origin of
Assessment
AST
(Forecast)
Summary of Effects
A negligible deterioration in local air quality
is expected with the scheme in place.
Changes in concentrations at properties
within 200 metres of the scheme are well
below the significance criteria for NO2 &
PM10 (2 & 1 micrograms per cubic metre
respectively, as an annual mean) & are
unlikely to be measurable.
Assessment
Overall PM10 score: 7.
Overall NO2 score: 17.
Number of properties with an improvement:
1. Number of properties with no change: 0.
Number of properties with a deterioration:
20.
EST (OYA
Evaluation)
Based on traffic flows, which are within +/10% of predictions, it is likely that the local
air quality due to traffic is as expected.
Likely to be as expected.
Greenhouse Gases
6.32
According to the DfT’s WebTAG guidance, (CO2) is considered to be the most important
greenhouse gas and, therefore, has been used as the key indicator for the purposes of
assessing the impacts of transport options on climate change. Although the focus is on CO2
emissions, the current guidelines are to express the change in terms of the change in the
equivalent tonnes of carbon released as a result of implementing a transport scheme.
Therefore the original forecasts figures have been converted to tonnes carbon for the
purpose of this evaluation.
47
M1 Junctions 6a to 10 Widening: One Year After study
Forecast Impacts - AST and ES
6.33
The greenhouse gas impact of the scheme was assessed using the guidance for regional air
quality modelling from the DMRB. This models fuel consumption related carbon emission
rates and requires the following basic inputs:




6.34
Annual average daily traffic flow to include heavy good vehicles (HGVs) and light duty
vehicles (LDVs);
Percentage of HGVs on each road;
Average speed of vehicles; and
Assessment year.
The AST stated that there would be a 9% (16,000 tonnes) increase in CO2 in the opening
year due to an increase in overall length of the route and an increase in traffic with the
scheme in place. This is equivalent to 4,364 tonnes of carbon.
Consultation on Greenhouse Gases
6.35
No consultation was carried out.
Evaluation of Greenhouse Gases
6.36
A summary of the evaluation compared to the forecast is shown in Table 6.6.
48
M1 Junctions 6a to 10 Widening: One Year After study
Table 6.6 - Summary of Greenhouse Gas Impacts
Origin of
Assessment
Summary of Greenhouse Gases Impacts
Emissions of CO2 are estimated to increase with the
scheme in place by around 9% in the opening year
(2008).
AST
(Forecast)
EST
(OYA
evaluation)
6.37
Increases are due to the increase in the increase in
the overall length of the route from Junction 6 to 10
with the scheme in place. The number of vehicles
on this part of the road network is expected to
increase with the scheme in place.
Increased emissions due to increased speeds and
traffic volumes.
Assessment
Total change in
CO2 emissions due
to
proposed
scheme
in
the
opening year is an
increase of 16,000
tonnes of CO2 per
year equivalent to
4,364 tonnes of
carbon (9%).
Increase of 16%
(14,500 tonnes of
carbon)
It can be seen that the increase in carbon emissions is greater than predicted. As the traffic
flows and speeds are broadly in line with forecast, the differences are likely to be due to the
following reasons:


The forecast was prepared in 2003 therefore a different version of the air quality
spreadsheet is likely to have been used; and
It is unclear from the documentation which links were included in the appraisal.
Landscape
Forecast Impacts - AST and ES
6.38
The AST stated that the M1 was already a prominent feature, cutting across the largely
agricultural landscape; the improvements will initially result in a loss of existing vegetation,
landtake of largely agricultural land and increased visibility of the motorway and associated
engineering elements. Proposed mitigation measures including mounding and planting would
reduce impacts, including offering improvements when compared to the existing situation.
Mitigation measures would also help to integrate the motorway, including the associated
engineering structures, within the wider landscape character and improve views from
adjacent visual amenity receptors including Redbourn. The overall assessment, taking into
account mitigation measures, would be slight beneficial at 15 years after scheme opening.
6.39
The NTS noted that the main effect of the widening proposals on landscape would result from
the loss of the existing vegetation along the motorway verges, changes to the earthworks and
provision of new sign gantries. New screening would be provided by earth mounding,
environmental barriers or new planting and these measures were expected to reduce the
impact of exposed sections of the works. Planting was expected to provide a screening
function from about the third year after the scheme opened, improving as the landscape grew
and matured.
6.40
The NTS also stated that there would be an adverse impact from the new sign gantries,
although existing landform, earthworks and planting would be used to maximise visual
mitigation.
6.41
Specific area of landscape mitigation were noted as;
49
M1 Junctions 6a to 10 Widening: One Year After study

Junctions 6a to 7 – Initially a low adverse impact on the eastern landscape through removal
of scrub and individual trees, but as new dense screen planting matured it would provide a
beneficial impact. Mounding and planting in the Bedmond Lane area would help reduce
visual impact. No changes to the western verge;

Junctions 7 to 8 – Extensive earth mounding and planting proposed on the west side to
provide immediate visual screening for properties in Leverstock Green and Westwick Row
area. Mounds would be carefully shaped to integrate into the local landscape. Westwick Hall
Farm and cottages experienced high adverse impact from the existing motorway and
proposals would result in motorway being nearer. Space on eastern side limited and screen
fencing would provide a visual barrier to views from Westwick Hall Farm area. Extensive
planting would help soften the appearance of the barrier. At Junction 8 the Grade II listed
property ‘Breakspears’ would experience a high adverse visual impact as a result of the
proposals;

Junction 8 to The Aubreys – the existing motorway was not highly visible over much of this
section and the impact was said to be relatively minor. Removal of some verge vegetation
would open up driver views to the wider landscape. Generally there would be no significant
increase in visual impact until Redbourn where most properties on the western fringe of the
village would experience moderate adverse visual impact. The combined mitigation of earth
mounding and fencing would provide immediate relief, and improving as the proposed
planting matured. The property ‘The Beeches’ would experience a moderate adverse impact
in the short term mitigated by dense planting either side of a solid barrier. The existing 12m
high lighting columns would need to be replaced with 15m high columns. The use of ‘high
cut-off’ lanterns was expected to reduce sky-glow and light spill beyond the motorway
improving the existing situation;

Junctions 9 to 10 – Little existing vegetation and long views out from the motorway to the
east would be retained with specific screen planting for isolated farms. At Junction 10 new
planting to the outside of the new roundabout and thickening up of existing hedges to
improve screening value would soften visual impact for nearby communities of Pepperstock
and Slip End. Mounding and noise fencing on the western edge of the new interchange
would provide some visual benefit as well as reducing noise. Approximately 0.46ha of Slip
End playing fields would be required.
Updates since the ES
6.42
The DSR stated that initially the widening would result in substantial or moderate impact to
the majority of key receptors. Early on, some key viewpoints would benefit from increased
screening of traffic, through new mounding, and environmental fencing, but until tree and
shrub planting matured, these elements would be intrusive in their own right. The visual
envelope would not change substantially, primarily because of the existing wide visibility of
the lighting columns, but traffic would be screened from a much wider area within the visual
envelope. The DSR summary stated that as planting establishes, the scheme would have a
neutral to slightly beneficial impact on the majority of viewpoints, but the vicinity of Westwick
Hall, Aubrey’s Fort and Breakspears would suffer slight adverse impact at Year 15. [It should
be noted that the summary tables in the DSR stated that at Beechtree Cottage and
Breakspears the impacts would be substantial adverse, and that at Aubrey’s Fort and
Westwick Hall the impacts would be moderate adverse. POPE has concluded that these
anomalies are a result of oversights in the report, rather than an underplaying of effects]
6.43
The DSR also stated that increased screening of traffic would reduce the adverse aspect of
the motorway as a defining feature of many of the landscape character areas, while the
substantial areas of tree planting would lead to a positive change in landscape character.
The scheme would reduce views over the wider countryside to travellers, but key long
distance views would be preserved. The overall effect on landscape character areas would
be slight beneficial. Offsite planting areas were identified at Potters Crouch, Green Lane at
Slip End, Redbourn and at Hemel Hempstead Road. Overall the long term impact on
50
M1 Junctions 6a to 10 Widening: One Year After study
landscape and visual aspects was considered to be slight beneficial, when mitigation
becomes fully effective.
6.44
The DSR also stated that the replacement of the existing lighting with a new system
conforming to current best practice would reduce light spill, and reduce the visibility of the
road lighting from surrounding locations, with a minor beneficial impact on sky glow and
residential receptors.
6.45
The DSR included photographic views from selected receptor viewpoints at pre-construction.
Where the visual effect of the scheme was considered to be slight adverse or worse, and
where possible, similar photographic views were taken during the POPE site visit to compare
the baseline views with the one year after views, and these are included in Appendix C:
6.46
6.47

EQ Waste Management, Appspond Lane;

Beechtree Cottage;

Hill End Cottage;

Dwelling at the Breakspears;

The Aubreys Fort SM;

PROW 20, Flamstead;

Church Road, Slip End;

Playing Field at Slip End; and

Dwellings east of Pepsal End Lane, Pepperstock.
The DSR also included receptors where the visual effect was considered to be slight adverse
or worse, but where a photographic record was not included. In these cases, a photograph
has been taken for this OYA report to enable a comparison to be made in the FYA report, and
these are included in Appendix C:

Dwellings in the vicinity of The Beeches;

Nicholls Farm;

Norringtonend Farm; and

PROW 23, Flamstead.
In line with POPE methodology where the original photographs were taken from private
property (Whitehouse Farm, dwelling at Sergehill, Westwick Hall, Benet Cottages and
Chequers Hill, Flamstead) comparison photographs at OYA have not been taken.
Consultation on Landscape
6.48
Natural England commented that it did not respond to post opening surveys.
6.49
Slip End Parish Council commented that there was considerable removal of mature trees
along the M1, and although these have been replaced to some extent with saplings, it will
take several years to obtain the status quo. In addition, the Parish Council negotiated with
the Contractor to build a bund at Pepperstock Bridge and to plant trees on the old road
surface area. Properties at Pepsal End Lane are subject to visual detraction because the
original tree cover has been removed. The lighting under the Church Road Bridge is
considered poor, although the actual M1 roadway lighting has not caused noticeable
additional light pollution. The lighting under the bridge at Junction 9 is considered excessive.
6.50
Flamstead Parish Council commented that it takes extreme exception to the day and night
lighting of the tunnel at Junction 9, and considers it to be a shockingly irresponsible waste of
energy.
6.51
Luton Borough Council commented that effects were as expected.
6.52
Dacorum District Council commented that there had been some loss of green landscape due
to the increased scale of the highway, that planting was not as extensive as before, but that it
51
M1 Junctions 6a to 10 Widening: One Year After study
will improve as it matures. The earthworks around Junction 8 appear satisfactory. The
landscaping at the Phoenix roundabout (A414 and Green Lane) is very poor. Rubbish at
Junction 9 roundabout is not cleared frequently enough. The size of the signage at Junction 9 is
too large and inappropriate for a rural location.
6.53
Markyate Parish Council commented that there has been a major impact on the local
landscape, and the efforts to alleviate it are not adequate. The M1 is a wider scar now, which
must be lessened along its length by more screening and trees. It is particularly wide open at
J8, which is an eyesore. Markyate Parish Council also commented that although some
planting had been undertaken, much more was required, that there was no evidence of
wildflower planting and that the scheme still looks bare a year on.
Evaluation of Landscape
6.54
Based on the As Built Landscape and Ecology Design drawings and site visit it was
confirmed that landscape mitigation measures have been implemented in line with the
proposals. The Official Completion Ceremony publicity leaflet notes that 190,000 trees and
shrubs including 4,150 oak trees have been planted.
6.55
The planting was generally found to be establishing satisfactorily, with grass cut in all plots
and along hedgelines, and weed-free circles clearly visible. A few semi-mature trees have
died. It is understood that planting was undertaken in stages, commencing in winter 20072008 from J10 to Gaddesden Lane, and from Gaddesden Lane to J6a in winter 2008 – 2009.
As may be expected, the later planting was found to be less well developed, but adequate
maintenance had clearly been carried out, including grass cutting and establishment of weed
free circles. No large areas of noxious weeds were observed, although there were
occasional docks in planted areas. It is understood that a five year aftercare programme is
included within the contract, and that a Landscape Management Plan (Five Year Aftercare
Period Post Construction 2009 – 2013) has been produced.
A HEMP (Handover
Environmental Management Plan) is to be produced at the end of the five year aftercare
programme, and should be obtained for the FYA report.
Figure 6.1 – Well maintained planting near Norringtonend Farm overbridge
6.56
Offsite planting at Bedmond Lane/Appspond Lane and at Nicholls Farm was establishing
well. It was not possible to check the offsite planting on private land at Breakspears. The
offsite planting on Hempstead Road (Nicky Line/Redbourn Bypass) was undertaken in winter
2009-2010 and was found to be in poor condition, with some sections missing. It is
52
M1 Junctions 6a to 10 Widening: One Year After study
understood that vandalism and theft have been a problem in this area, and that the matter is
being addressed as part of the ongoing landscape maintenance programme (See Figure
6.2).
Figure 6.2 – Vandalised offsite planting on Hempstead Road
6.57
As built drawings indicate that the wildflower plots and areas planted with spring bulbs have
been provided (HA publicity indicates that 2,000 native English bluebells have been planted),
although due to the time of year of the POPE visit, it was not possible to evaluate how well
the areas have established during the site visit. However, the calcareous grassland areas
and scrapes were discernible, and the scheme monitoring results for these are summarised
in the biodiversity section (See Figure 6.3.). It is suggested that for the FYA evaluation the
site visit could be programmed to coincide with wildflower flowering. The wildflower areas
appear to have been maintained, with the arisings raked off after cutting.
Figure 6.3 – Calcareous grassland near Watery Lane overbridge
53
M1 Junctions 6a to 10 Widening: One Year After study
6.58
Five of the readily accessible balancing ponds were visited: all contained marginal vegetation,
with some wildflowers and scattered noxious weeds on the banks. (See Figure 6.4). The
scheme monitoring results for the ecological ponds are summarised in the biodiversity
section.
Figure 6.4 – Well vegetated balancing pond close to Hempstead Road
6.59
The moderate adverse initial effect on local landscape character areas is largely as a result of
loss of some existing vegetation as expected within the motorway boundary. The parallel
distributor roads between junctions 7 and 8 have created a short stretch of very wide
motorway corridor, particularly when viewed from an overbridge. The new and widened
bridges and reconstructed junctions have fitted well into the landscape. Vegetation identified
for retention has been retained as expected. The slight beneficial effect on landscape
character predicted at Design Year will depend on the effective establishment of planting to
reduce the influence of the M1 on the wider landscape, and this should be reviewed as part of
the FYA report.
6.60
The visual effect of the scheme on selected receptors is illustrated in Appendix C. In all
cases, the proposed mitigation planting, mounding and environmental barriers were in place,
but it was too soon to determine the screening effect of the planting, and this should be
reviewed as part of the FYA report.
6.61
Dacorum District Council commented that the signage at Junction 9 was too large for a rural
location. Following the site visit, POPE concludes that in general the signage and provision
of lighting columns was as expected for a motorway in a rural/semi-rural location. POPE did
not undertake an assessment if the night time lighting effects.
6.62
The feedback from Slip End Parish Council regarding construction of a bund and additional
planting at Pepperstock Bridge did not form part of the DSR (Detailed Scheme Review)
proposals and was not evaluated during the site visit. The visual detraction relating to loss of
tree cover at Pepsal End Lane was as expected.
6.63
The effect of underbridge lighting at Junction 9 was not considered in the DSR, possibly
because of changes in the requirements for tunnel lighting occurring at the same time,
however it has resulted in strong comments from consultees. The requirements for tunnel
lighting changed with the revision of BS 5489 Code of practice for the design of road lighting
– Part 2: Lighting of Tunnels, introduced at the end of 2003. The M1 6a-10 Widening
Lighting Design, Junction 9 Friars Wash Underpass Lighting Study Report, November 2005,
54
M1 Junctions 6a to 10 Widening: One Year After study
concluded that daytime lighting of the tunnel would be required to meet the current standards.
It is recommended that the requirement for underbridge lighting could be subject to more
local consultation in future scheme design, to ensure that the public are aware of the
necessary criteria.
6.64
Table 6.7 provides a summary of the landscape evaluation, whilst
6.65
6.66
6.67
Table 6.8 at the end of the section compares the predicted effects, mitigation and evaluates
the impacts.
Table 6.7 - Summary of Landscape Impacts
Origin of
Assessment
Summary of Effects
Assessment
The overall assessment, taking
into account mitigation measures,
would be slight beneficial at 15
years after scheme opening.
AST
(Forecast)
The M1 is currently a prominent feature, cutting
across the largely agricultural landscape; the
improvements will initially result in a loss of existing
vegetation, landtake of largely agricultural land &
increased visibility of the motorway & associated
engineering
elements.
Proposed
mitigation
measures including mounding & planting will reduce
impacts, including offering improvements when
compared to the existing situation. Mitigation
measures will also help to integrate the motorway,
including the associated engineering structures, with
the wider landscape character & improve views from
adjacent visual amenity receptors.
Generally as expected at this
OYA stage.
EST (OYA
evaluation)
Mitigation measures generally provided in line with
proposals. One area of offsite planting subject to
vandalism.
Underbridge lighting at Junction 9
resulted in strong negative comments from
consultees. Too soon to evaluate screening value
or establishment of new planting and seeding, and
55
M1 Junctions 6a to 10 Widening: One Year After study
should be reviewed as part of the Five Year After
report.
Table 6.8 - Summary of predicted landscape effects, proposed mitigation and evaluation of impacts
Effects on Landscape
Proposed Mitigation
Evaluation
Adverse initial effect on
some local character
areas: beneficial effect
by Design Year
Mounding and screen fencing
constructed where appropriate.
Predominantly locally occurring
native tree and shrub replacement
planting.
Considerable mounding and screen
fencing as expected and planting
undertaken within M1 corridor and
offsite, but too soon to evaluate
screening effects of planting and benefit
to landscape character.
Planting of standard trees in
selected locations, along with
transplants and feathered trees, to
give more immediate screening.
Some standard trees have failed and
should be replaced during next planting
season. Transplant and feathered
trees in good condition and likely to
establish more effectively. Screen
fences, mounding and hedges in place
as expected. Evergreen species used
as expected to improve winter
screening.
Replacement planting, new
screening planting and infill
planting where required and land
take allows. Screening fencing
where insufficient space for
planting. Some off site planting
under licence. Inclusion of
evergreen species in tree/shrub
mix.
Considerable planting undertaken
within M1 corridor and offsite, but too
soon to evaluate screening and benefit
to visual receptors. Screen fences,
mounding and hedges in place as
expected. Evergreen species used as
expected to improve winter screening.
Significant loss of
existing mature
vegetation.
Widened road,
realigned slip roads and
gantries visible to close
visual receptors.
56
M1 Junctions 6a to 10 Widening: One Year After study
Biodiversity
6.68
The AST stated that the impacts of the widening scheme were judged on the basis that many
of the habitats adjacent to the motorway had already been bisected and degraded in quality
and that further damage would be limited. The majority of the impacts were assessed as
being slight adverse on this basis. Impacts on protected species were envisaged to be
negligible. Proposed mitigation such as replacement of bat roosts, re-planting of native
species-rich hedges, creation of species-rich grassland and the creation of wildlife ponds
near Junction 8 would go some way to addressing the impacts of the scheme. The overall
impact was assessed as slight adverse.
6.69
The NTS noted that there were no designated sites directly affected by the scheme. Some
22 sites of varying nature conservation interest were identified where proposals were likely to
have some impacts, in most cases of negligible importance and any losses would be
adequately restored over the medium term (5 – 7 years) by planting to set ecological policies.
The loss of verge vegetation would not be important ecologically as most of it was not of
significant nature conservation value. Replacement hedgerows would reflect local species in
order to extend habitats for the benefit of wildlife.
6.70
Specific biodiversity impacts and mitigation were noted as;

Junctions 6a to 7 – none mentioned;

Junctions 7 to 8 – alteration of the existing balancing ponds would be required but the mature
oak and ash trees would be retained where possible, natural regeneration of the existing
scrub vegetation would be encouraged and replacement planting where appropriate.
Remodelling of Junction 8 would make the redundant slip road loop area available for either
dense woodland or large scale grassland habitat creation;

Junction 8 to the Aubreys – the widening of the motorway would give the opportunity to
extend habitats for locally native flowering species. Where appropriate thin sowings of native
grasses would be used to allow natural colonisation from local seed sources, elsewhere
species-rich seed mixes would be used;

The Aubreys to Junction 9 – Retaining walls would be used to reduce the landtake in the
vicinity of the ancient woodland site Bury Wood. The wood would not be directly affected but
some trees and scrub on the highway verge would be removed which provided woodland
edge protection. Earthworks might cause changes in groundwater patterns. New planting
would be re-established;

Junction 9 to 10 – none mentioned.
Updates since the ES
6.71
The DSR noted that the main direct impacts of the scheme would be the realignment of the
M1, which would bring the road closer to several areas of high ecological habitats and
protected species, loss and severance of habitats, particularly linear habitats, mature trees
and woodland areas. Further survey work was recommended for bats, badgers, great
crested newts and reptiles, and as mitigation measures could not therefore be formulated at
that stage, no overall effect was stated. The additional survey work was undertaken and
suggested mitigation measures were set out in ‘Ecology Design Phase 1b’, January 2006.
6.72
The EDP stated that approximately 25 mature trees would be lost, one badger sett could be
disturbed as the motorway would be closer to the sett, there would be a total loss of 2080m of
hedgerows, one pond would be lost, a total of 10,996m2 of land would be lost from County
Wildlife Sites and loss of hedges and bridges used as foraging areas and flight paths could
impact on bats. Ten ponds were surveyed for great crested newts. No great crested newts
were found in water bodies within 500m of the site, except in one pond, from which it was
57
M1 Junctions 6a to 10 Widening: One Year After study
considered that the newts were very unlikely to roam as far as the motorway verge, and that
no great crested newt mitigation was necessary. No reptiles were found at any of the survey
sites, possibly because the populations were isolated when the original motorway was built.
Consultation on Biodiversity
6.73
Natural England commented that it did not respond to post opening surveys.
6.74
Luton Borough Council commented that the scheme had been implemented as expected.
6.75
Central Bedfordshire Council had no comments.
6.76
The Bedfordshire, Cambridgeshire and Northamptonshire Wildlife Trust had no comments.
6.77
Slip End Parish Council commented that the HA had arranged additional marginal planting
around the balancing pond near Pepperstock Bridge to improve the wildlife habitat. There
has been concern that increased rabbit and deer damage to crops in the local allotments has
been as a result of habitat disturbance.
Evaluation of Biodiversity
6.78
Based on the site visit and As Built drawings it would appear that most of the ecological
mitigation measures have been implemented in line with the proposals in the EDP. The
mitigation measures proposed were:

construction of 2 ecological ponds;

installation of bat boxes;

installation of bird boxes as an ecological enhancement

planting of standard trees in known bat foraging areas;

installation of replacement bat roost features in new bridges;

no lighting introduced in replacement underbridges that were originally unlit;

construction of vegetated balancing ponds;

planting of native trees, shrubs and hedges to replace those lost;

sowing of wildflower seed mixes; and

installation of permanent badger fencing.

creation of an artificial badger sett as an ecological enhancement
The Ecological Management Plan, March 2009, (EMP), details the monitoring requirements for
bats, badgers, birds, ecological ponds, calcareous grassland and bluebells for 5 years from
2009 – 2013, and the findings of the 2009 surveys are set out below.
Bats
6.79
Post construction ecological monitoring for 27 bat boxes was carried out in May 2009 when 3
common pipistrelles were identified flying through the Nicky Line tunnel. 6 boxes were not
accessible due to a locked gate. On September 23 2009 an inspection of bat boxes across
the scheme found no evidence of droppings. A dusk survey at Nicky Line Bridge on 30
September 2009 identified common pipistrelles on either side of the bridge, and an inspection
of bat boxes in the vicinity found bat droppings in one box. No myosotis or long-eared bats
have been recorded using the tunnel since refurbishment, and the report considers that the
constant lighting of the Nicky Line underpass (a County Wildlife Site) may be deterring these
bats from using the tunnel. The report recommends that the day time lighting is made motion
sensitive and that night time lighting is reduced or the lamps hooded to direct the light onto
the ground.
Badger
6.80
Post construction ecological monitoring for badgers was carried out on 18 June 2009. The
existing badger sett was found to have, 3 holes collapsed and there was no latrine or obvious
58
M1 Junctions 6a to 10 Widening: One Year After study
pathway. It was concluded that the sett not been used for several months. The length of
badger fencing was found to be intact. An artificial badger sett was found to be in good use.
Birds
6.81
The Non Technical Summary, DSR and EDP did not identify specific mitigation or monitoring
requirement for birds, but the EMP states that 85 bird boxes have been installed. Post
construction ecological monitoring for birds was carried out on 20 and 26 May 2009 when
70% of bird boxes showed various degrees of usage, and 20% were occupied by young
chicks.
Ponds
6.82
Post construction monitoring of ecological ponds was carried out on 4 June 2009. The pond
at Punchbowl Lane did not contain water or aquatic vegetation. On 8 September 2009 it
contained some water but no aquatic vegetation, although some terrestrial vegetation was
present, and the Junction 8 pond contained no water or vegetation. By November 2009, both
ponds contained water, but no aquatic vegetation. Inspections carried out during summer
2010 indicated no change, and the situation is being reviewed as part of the EMP and LMP.
Calcareous grasslands
6.83
Creation of calcareous grassland was an ecological enhancement measureand is being
monitored because creation of specific calcareous grassland is an HA BAP priority habitat for
its value for butterflies. Post construction ecological monitoring for calcareous grassland was
carried out on 18 June 2009 and on 8 September 2009, when it was stated that the seeding
had been generally successful, with a lot of fine grasses.
Bluebells
6.84
Introduction of bluebells was an ecological enhancement measure.
Post construction
ecological monitoring for bluebells was carried out on 26 May 2009, when it was estimated
that 20% of the planting had been successful, with the planted area mostly encroached by
nettle. In view of this poor result, the report recommends that a repeat survey is undertaken
in May 2011.
6.85
All balancing ponds visited in August 2010 for POPE contained water, had been planted with
aquatic plants and were well vegetated.
6.86
The MAC animal mortality data from 13 May 2005 to 12 March 2006 (pre-construction) stated
that 2 deer, 1 cat, 1 dog and 1 badger were found dead between Junctions 6 and 10, and that
between 09 August 2009 to 27 July 2010 (post construction) that 2 dogs, 2 foxes, 2 deer and
1 swan were found dead between Junctions 6 and 10. For comparison, it is suggested that
the figures are requested for the 5YA report.
6.87
It is too soon to fully evaluate the effectiveness of the mitigation measures, and the results of
ongoing monitoring set out in the EMP should be considered as part of the FYA report.
6.88
Table 6.9 provides a summary of the biodiversity evaluation whilst Table 6.10 at the end of
the section compares the predicted effects, mitigation and evaluates the impacts in detail.
Table 6.9 - Summary Biodiversity Impacts
Origin of
Assessment
Summary of Effects
AST (Forecast)
The impacts of the widening scheme have been judged on
the basis that many of the habitats adjacent to the
motorway have already been bisected & degraded in
quality & that further damage will be limited. The majority
of the impacts have been assessed as being slight
adverse on this basis. Impacts on protected species are
Assessment
Slight Adverse
59
M1 Junctions 6a to 10 Widening: One Year After study
envisaged to be negligible. Proposed mitigation such as
replacement of bat roosts, re-planting of native species
rich hedges, creation of species-rich grassland& & the
creation of wildlife ponds near J 8 should go some way to
addressing the impacts of the scheme.
EST
(OYA
Evaluation)
Mitigation measures provided for species and habitats.
Too soon to evaluate effectiveness and should be
reviewed as part of the Five Year After report.
Bats,
badgers, calcareous grassland, bluebells, ecological
ponds and bird boxes monitoring report received.
Monitoring of most species to continue until 2013.
Lighting of Nicky Line underpass requires change to
reduce impacts on bats.
Ecological ponds not yet
effective.
Likely to be as
expected based on
the
information
available at this OYA
stage.
Table 6.10 - Summary of predicted biodiversity effects, proposed mitigation and evaluation of impacts
Vegetation
Designated Sites
Aspect
Predicted Impact
Total 10,996m2 lost from
County Wildlife Sites.
Loss of hedgerows and
subsequent loss of
connectivity for wildlife.
Mitigation Measures
Evaluation
Minimise loss of ancient
woodland habitat that
cannot be created
elsewhere.
Replacement habitats have
been incorporated into the
scheme and management and
maintenance is ongoing for 5
years during the aftercare
period.
Replanting of and
restoration of hedgerows
where possible. Species
rich locally occurring native
tree/shrub mix to improve
biodiversity.
Extensive hedgerow planting
undertaken and establishing
satisfactorily. The ongoing
establishment of planting
should be reviewed at the Five
Year After stage.
60
M1 Junctions 6a to 10 Widening: One Year After study
Predicted Impact
Ecological
ponds
Badgers
Birds
Bats
Aspect
Mitigation Measures
Evaluation
New tree and hedgerow
planting, and bat boxes
provided and being used.
Ceiling of Nicky Line
underpass painted black.
Lighting of Nicky Line tunnel
not conducive to bat foraging
and flight paths.
Loss of 25 trees with bat
roost potential. Loss of
hedges and bridges used
as foraging areas and
flight paths. Disturbance
at Nicky Line bridge and
loss of 1 roost.
Bat boxes to be provided,
maintained and monitored.
Hedges to be planted. Use
of low level directional
lighting and black painted
underpass ceiling at Nicky
Line Bridge.
Loss of nesting habitat
Minimise loss of woodland
habitat. Provide and
monitor 85 bird boxes.
New tree and hedgerow
planting, and 85 bird boxes
provided.
One active sett and one
disused sett identified in
the EDP.
Provision of badger fencing
and planting of fruiting
tree/shrub species in known
foraging area. Construction
of artificial sett as
enhancement measure.
Badger fencing intact. Artificial
sett used by badgers for
breeding in 2009. Fruiting
tree/shrub species used where
appropriate.
Loss of ecological pond
near Junction 9.
Creation of 2 new ecological
ponds, to revegetate
naturally.
Standard trees in the vicinity of
bat roosts are establishing
well.
Ponds at Punchbowl Lane and
close to Junction 8 holding
water seasonally, but no
aquatic vegetation yet present.
Heritage of Historic Resources
6.89
The AST stated that the scheme would only affect known archaeological sites partially disturbing the surrounds of the Scheduled Ancient Monument (SAM), but not the designated
area, and only elements of the 20th century landscape. Impacts of the scheme on buildings,
Conservation Areas and Parks would be indirect (on their setting), and no greater than those
posed by the existing road. Impact on buried archaeological remains would be major, but
these remains (if found to be present) were not likely to be of more than regional importance.
The impact overall was assessed as slight adverse.
6.90
The NTS noted that there were 4 known areas of archaeological interest near to the M1. The
most important was The Aubreys SAM. Twelve Grade II listed buildings were noted within
200m of the motorway, none would be directly affected. Landscaping and / or earth
mounding would be designed to reduce visual impact of the motorway on the conservation
areas of Flamstead, Potters Crouch and Redbourn.

Junctions 6a to 7 – to mitigate visual impact on Potters Crouch Conservation Area strong
linear ‘off-site’ planting to both sides of Bedmond Lane to strengthen existing hedges and to
the fringe of the village;

Junctions 7 to 8 – none mentioned
61
M1 Junctions 6a to 10 Widening: One Year After study

Junction 8 to the Aubreys - The Aubreys SAM, a large banked ditch enclosure of prehistoric
date to the west of the M1. Land take would be minimised alongside and use of a retaining
wall would mean the monument itself would remain unaffected and intact. The motorway
would come within 3m of the limit of the SAM.

The Aubreys to Junction 9 – none mentioned;

Junctions 9 to 10 – earth mounding and fencing to screen Redbourn village.
Updates since the ES
6.91
The DSR noted that seven sites had been identified that required trial trenching as mitigation,
and the residual impact would be neutral. Previous geophysical survey and trial trenching at
the Aubreys Scheduled Monument established that the site was of national importance, that
no further evaluation was required, and that the residual impact was minor negative. It was
concluded that after mitigation planting has matured, the overall residual effect on the settings
of some listed buildings, such as St Mary’s Church, Redbourn (Grade 1), Breakspears (Grade
2), St Andrew’s Church (Grade 2), Westwick Hall, (Grade 2), Westwick Cottages, (Grade 2),
Nicholls Farm, (Grade 2), and St Agnells Farm, (Grade 2), would be neutral.
6.92
The Archaeological Design Part 2: Mitigation Strategy (2006) (ADP2) set out the sites where
archaeological excavation, a scheme wide watching brief, or a targeted watching brief were
proposed, and was submitted to the consultees for approval prior to starting work on each
site.
Consultation on Heritage
6.93
English Heritage (EH) commented that in relation to the Aubreys the impacts are as
expected.
6.94
St Albans District Council commented that generally as a whole length the impact is probably
as expected, but no report has yet been seen, and so potentially no mitigation of the loss has
occurred. A popular publication of the post excavation report, related to transport had also
been discussed. A timetable of the work and EH Management of Research Projects in the
Historic Environment is required. There has been no consultation on the post excavation or
standing structure report, including the need to date features at junctions 8 and 9. At the
Aubrey’s Scheduled Monument it is considered that more excavation of the ditches was
probably required to mitigate, although this was with the benefit of hindsight. At Luton Hoo
Park/Garden of Special Historic Interest it is considered that there will be an increase in noise
levels, from the closer proximity of the road.
6.95
Central Bedfordshire Council had no comments.
6.96
Markyate Parish Council commented that there was no evidence that any consideration was
given to heritage, but that the Nicky Line underpass was preserved as a walk and cycleway.
6.97
Slip End Parish Council commented that an archaeological survey was carried out, but
nothing of significance was found.
Evaluation of Heritage
6.98
From the unpublished draft Post Excavation Assessment Report January 2008 (PEAR) (, it is
understood that The Aubrey’s SAM and a further 8 sites had been identified at the PI for further
evaluation and mitigation. In addition, a number of other sites were identified and evaluated to
reduce the risk of discovering remains during the watching brief required during construction. The
PEAR included the results of the mitigation undertaken (excavation, targeted watching brief or site
wide watching brief). The draft results of the work, where positive features were discovered are
set out in Table 6.11. These largely indicate that finds were of a minor nature, including pottery,
flints and building material.
Table 6.11 - Summary of heritage evaluation, mitigation and results
62
M1 Junctions 6a to 10 Widening: One Year After study
Evaluation area
Mitigation
PEAR Result
Junction 10 area
Excavation, targeted
watching brief
Minor features discovered,
possible ring ditch and one
flint, mostly undated
Borrow Pit area
Excavation
Minor features discovered,
possible prehistoric
settlement, mostly undated
Area around J9 and A5
Watling Street
Excavation
Prehistoric and late Iron Age –
Roman features, mostly
pottery and building material.
Area 6/P 2km north of the
Aubrey’s
Evaluation watching brief
Roman linear features
discovered
Area 7/M 1km north of the
Aubrey’s
Targeted watching brief
Late Iron Age – Roman linear
features discovered
The Aubrey’s
Excavation
Hillfort ditch and a few other
features including Iron Age
pottery, very poorly dated
J8 compound
Site wide watching brief
Scattered features, including
prehistoric pottery discovered,
but mostly Medieval features
Hogg End Lane Crossing
Targeted watching brief
A few linear features including
flint flakes discovered and
Bronze/Iron Age pit
Excavation
Dense occupation, late Iron
Age, Roman and Medieval
pottery discovered. Also
cremation and human skull
recovered.
Area 3/G J8
6.99
POPE understands that the PEAR was sent to all consultees in March 2009 and that no
responses were received, and that a draft post excavation technical report has recently been
sent to consultees for approval, and a copy should be available for the FYA POPE report. It
is understood that a popular report has not been produced. The ADP2 stated that any finds
were to be archived in St Albans Museum and this should be confirmed for the FYA report.
6.100
The feedback from Markyate Parish Council relating to lack of consideration of heritage is
unsupported, although as Parish Councils are not statutory consultees they would not
necessarily be aware of the work undertaken.
6.101
PThe site visit confirmed that planting proposed in the DSR to mitigate the effects on the
setting of listed buildings has been undertaken in the vicinity of St Mary’s Church (Redbourn),
Breakspears, St Andrew’s Church (Woodside), Westwick Hall and Westwick Cottages,
Nicholls Farm, and St Agnells Farm. The effectiveness of the planting should be assessed in
the FYA evaluation. It is not considered that the setting of Luton Hoo has been affected by
the scheme; the historic park and garden is at some distance from the M1 separated by
existing vegetation and an A road.
6.102
The site visit also confirmed that the impact on the Redbourn and Potters Crouch
Conservation Areas (as set out in the Landscape section of the DSR) was as expected, and
that there would be no direct impact on the Redbourn Conservation Area, and that the
improved screening planting had been carried out to improve the setting of the Potters
63
M1 Junctions 6a to 10 Widening: One Year After study
Crouch Conservation Area. Screening and planting mitigation measures had been carried
out as expected to reduce the impact on the setting of the Aubreys Fort Scheduled
Monument (medium adverse at Year 15, as set out in the Landscape section of the DSR).
6.103
A summary of the evaluation compared to the forecast is shown in Table 6.12
Table 6.12 - Summary of Heritage Impacts
Origin of
Assessment
Summary of Effects
Assessment
AST
(Forecast)
The scheme will only affect known archaeological sites
partially - disturbing the surrounds of the SAM, but not the
designated area, and only elements of the 20th century
landscape. Impacts of the scheme on buildings,
Conservation Areas and Parks will be indirect (on their
setting), and no greater than those posed by the current
road. Impact on buried archaeological remains will be
major, but these remains (if found to be present) are not
likely to be of more than regional importance.
Slight
adverse
EST
(OYA
Evaluation)
The post-excavation technical report is not yet published
and should be available at FYA. Effects on Conservation
Areas as expected. With regard to the setting of listed
buildings and screening of the Aubreys SAM, the
effectiveness of proposed mitigation planting should be
assessed at FYA.
As expected
64
M1 Junctions 6a to 10 Widening: One Year After study
Water Environment
6.104
The AST stated that the use of current good practices in accordance with Environment
Agency guidelines during the construction phase and the implementation of Vegetative
Treatment Systems during the operational phase should significantly reduce any potential
impact to controlled waters. The scheme would include improvements to: pollution control,
storm water attenuation, discharge to groundwater and would reduce the risk of accidental
spillage. The installation of a new highway drainage system to treat water from the road
would improve the management of both water quality and quantity. The impacts were
assessed to be slight beneficial overall.
6.105
The NTS noted that the majority of existing surface water from the motorway drained via
soakaways into the ground except between Lybury Lane and Coles Lane where the outfall
was to the River Ver at Junction 9. The new highway drainage system would outfall to
watercourses where possible rather than use soakaways to reduce the risk of pollutants
entering the ground water, and particularly in the groundwater protection area around
Junction 9. Between Punchbowl Lane and Junction 10 surface water run-off would be
collected and stored in balancing ponds before out-falling to the River Ver. Pollution control
measures would be incorporated into the scheme.
Updates since the ES
6.106
The DSR stated that sufficient pollution control measures had been built into the project
design to ensure that discharges of surface run off would not have a detrimental effect on the
receiving water, resulting in a neutral impact on water quality. The implementation of surface
water attenuation measures as part of the drainage strategy would ensure that local flooding
was kept to a minimum. The DSR also stated that the scheme could have a potential minor
beneficial effect on the aquatic environment of the River Ver as a result of the improving flow
during periods of low flow, through an increase in the volume of surface water runoff
discharged to the river.
6.107
The DSR stated that the road drainage and treatment system included the following
measures to minimise pollution of watercourses:

Silt traps and oil interceptors to remove the majority of the suspended solids and
hydrocarbons in the road runoff;

Detention basins and balancing ponds where suspended solids can be removed
before final discharge into receiving watercourses; and

Soakaways, swales, detention basins and balancing ponds to attenuate the flow of
surface water drainage to minimise the risk of localised flooding, up to 100 year
events.
Consultation on Water Environment
6.108
Dacorum District Council had no comments on water quality and drainage.
6.109
The Environment Agency (EA) commented that it hoped that there has been an improvement
in water quality as a consequence of the protection measures that were built into the scheme,
and that the surface water drainage systems and balancing pond measures have been
carried out to high standards.
6.110
Slip End Parish Council commented that they are unaware of any disturbances to the water
table, and that no watercourses in the parish were affected. However, it considers that the
balancing tank adjacent to the Church Road Bridge looks like an industrial site, and would
benefit from some landscaping, including tree planting outside the security fence.
65
M1 Junctions 6a to 10 Widening: One Year After study
6.111
Markyate Parish Council (MPC) commented that they should be given reassurance that the
River Ver has not been further marginalised by the widened structure. In addition, MPC
commented that the containment pools at Junctions 9 and 10a are essential to prevent
pollution in case of an accident, but they are not camouflaged.
Evaluation of Water Environment
6.112
The As Built Drainage drawings were not made available to POPE, and these should be
requested at FYA. The DSR did not state how many balancing ponds were already present
or how many new ponds were proposed, but the Phase 2 Environmental Masterplan showed
9 proposed balancing ponds. The As Built Landscape and Ecology Design drawings show
that 8 of these were constructed, and that two ecology ponds were also constructed as
ecological enhancement. Five of the readily accessible balancing ponds were visited for
POPE: all contained well developed marginal vegetation, and their effectiveness as
vegetative treatment systems should be considered at FYA.
6.113
As noted in the Biodiversity section, the ecological ponds are not yet holding water all year or
vegetated, and are being assessed as part of the LMP and EMP.
6.114
Both Slip End and Markyate Parish Councils commented on lack of screening at the
balancing ponds; these structures are visually prominent within the landscape and could have
been softened by planting or some form of visual screening..
6.115
The course of the River Ver flows under Junction 9, which has been widened as part of the
scheme. Markyate Parish Council expressed concern about the ‘marginalistion’ of the River,
but this was not raised as an issue in the NTS or DSR, and the impacts on the river in the
DSR were assessed as positive.
6.116
It is suggested that water issues are evaluated further as part of the five year after study to
determine the effects over a more representative period. The Environment Agency should be
consulted again as part of the evaluation.
6.117
A summary of the evaluation compared to the forecast is shown in Table 6.13.
Table 6.13 - Summary of Water Impacts
Origin of
Assessment
Summary of Effects
Assessment
Slight beneficial
AST
(Forecast)
The use of current good practices in accordance with
Environment Agency guidelines during the construction
phase & the implementation of Vegetative Treatment
Systems during the operational phase should
significantly reduce any potential impact to controlled
waters. The scheme will include improvements to:
pollution control, storm water attenuation, discharge to
groundwater & will reduce the risk of accidental
spillage. The installation of a new highway drainage
system to treat water from the road would improve the
management of both water quality and quantity.
EST (OYA
Evaluation)
POPE is not aware of any pollution incidents or that the
mitigation measures are performing other than as
expected. EA consider the mitigation to be carried out
to high standards The longer term effectiveness of
drainage measures should be re-considered at Five
Years After
Based on
information
available As
expected at
OYA.
66
M1 Junctions 6a to 10 Widening: One Year After study
Physical Fitness
6.118
The AST stated that crossing facilities and Public Rights of Way would be maintained and
improved/replaced when disrupted. Other improvements would also be incorporated as part
of the scheme. Journey distances by non-motorised users would increase by approximately
800m equating to an additional journey time for pedestrians of 10 minutes across the
scheme. The scheme was unlikely to reduce the number of walking/cycling trips made once
the scheme has been implemented. Any increase in physical activity was unlikely to be
significant enough to contribute to the overall health strategy. The impacts were assessed to
be neutral.
6.119
The NTS stated that the scheme impacts on pedestrians would be negligible with a small
benefit in the long term gained due to all existing routes being retained and at a number of
locations a greater separation achieved between the footpath and motorway.
Updates since the ES
6.120
The DSR stated that where a route had already been severed by the motorway, it would be
further shortened by the amount of the proposed widening. Where a route had already been
diverted to run adjacent to the motorway boundary, it would be diverted to run adjacent to the
new boundary. Where a route crossed the motorway by means of an existing structure, the
route would be maintained via modified replacement structures. 22 footpaths would be
affected by the proposals, with neutral impacts on 20 of these.
6.121
The impacts on the footpath 7 (St Michael Parish), and footpath 9 (Redbourne) was
considered to be minor negative, because of a slight increase in journey time in each case.
The impacts on all bridleways, designated cycleways and other designated routes were
considered to be neutral. No overall impact was stated.
6.122
As noted in the biodiversity section above, the proposals did not include lighting for
underpasses that were not originally lit.
Consultation on Physical Fitness
6.123
Central Bedfordshire Council stated that one public footpath and one bridleway way that ran
parallel with the motorway had been moved as expected. However the Rights of Way Officer
stated that it had not always been possible to achieve the agreed widths for the footpath or
bridleway due to constraints on site. No adverse comments from the public have been
received.
6.124
Slip End Parish Council commented that the public footpath near Pepperstock bridge has
been reinstated, and that it was in communication with the HA and Central Bedfordshire
Council regarding alterations to footpaths and bridleways alongside the M1. Central
Bedfordshire Council commented that the Slip End Parish Council requests had been
received after consultation and were too late to be accommodated during construction and
could not now be implemented.
6.125
Markyate Parish Council commented that public rights of way had been retained as expected,
and had no comments relating the footpaths provided or provision for cyclists and
equestrians.
Evaluation of Physical Fitness
6.126
It is understood that no post opening Non-Motorised User / Vulnerable User (NMU/VU)
surveys have been undertaken and no new NMU/VU surveys have been carried out
specifically for POPE which would provide any quantifiable measures of use of the PROWs.
At the time of the site visit no pedestrians, cyclists or horse riders were observed using
footpaths, cycleways or bridleways.
67
M1 Junctions 6a to 10 Widening: One Year After study
6.127
National Cycle Network 57 crosses beneath the M1 along the route of the dismantled railway
(the ‘Nicky Line) between Junctions 7 and 8. The new extended tunnel includes high levels
of lighting throughout to increase perception of security, although it should be noted that the
level of lighting is considered in the EMR to be disadvantageous for bats.
6.128
The M1 Junctions 6a to 10 Widening – Non Motorised User Context Report includes a
proposal for a cycle path along the A414 (former M10) from the National Cycle Route 6
(NCR6) at Watford Road to Buncefield Roundabout (East of Hemel Hempstead adjacent to
M1 Junction 8). As stated in the section on accessibility, this has not yet been implemented,
but it is not considered to have a significant effect on physical fitness.
6.129
It is noted that when the M1 was originally constructed in the 1950’s, a number of footpaths
and roads were severed, restricting movements across the M1. The recent widening of the
M1 does not create any further severance and the impact is considered to be neutral as
expected.
6.130
Mitigation planting to integrate the footpaths and bridleways into the landscape has been
undertaken as proposed, but it is too soon to evaluate the effectiveness of the planting
measures and this should be considered as part of the FYA evaluation.
6.131
Based on the site visit and desk study, PROWs have been retained and diverted as proposed
and the impacts on footpaths, bridleways and cycle facilities are in line with expectations,
although the recommendations for lighting of tunnels has changed since the NTS and DSR.
6.132
A summary of the evaluation compared to the forecast is shown in Table 6.14.
Table 6.14 - Summary of Physical Fitness impacts
Origin of
Assessment
Summary of Effects
Assessment
AST
(Forecast)
Crossing facilities & Public Rights of Way will be
maintained & improved/replaced when disrupted.
Other improvements have also been incorporated
as part of the scheme. Overall the proposals
suggest that journey distances by non-motorised
users will increase by approximately 800m equating
to an additional journey time for pedestrians of 10
minutes across the scheme. The scheme is unlikely
to reduce the number of walking/cycling trips made
once the scheme has been implemented. Any
increase in physical activity is unlikely to be
significant enough to contribute to the overall health
strategy.
Neutral
EST (OYA
Evaluation)
No further severance of footpaths, and diversions
implemented as expected.
One footpath not
constructed to expected width. One cycleway not
yet constructed and should be considered at Five
Years After. On the whole the NMU provision has
achieved its objectives.
As expected
Journey Ambience
6.133
The AST stated that driver’s frustration and fear of potential accidents was likely to reduce.
Improved route signs and road information should reduce the driver’s uncertainty, whilst the
improvements in the view from the road were likely to improve (despite some new restrictions
to views). The impacts were assessed to be beneficial overall.
68
M1 Junctions 6a to 10 Widening: One Year After study
6.134
The NTS noted that the proposed scheme would have a highly beneficial effect in the short
and medium term for users of the motorway and adjacent routes. The provision of improved
road capacity would assist in the reduction of congestion and benefit drivers by reducing
delay, inconvenience and journey times, and by improving safety and alleviating traffic flows
on unsuitable routes adjacent to the motorway.
Updates since the ES
6.135
The DSR stated that the provision of new lanes on the southbound and northbound
carriageways would result in fewer cars per lane, easing congestion, reducing queues and
enabling drivers the ability to drive at a more consistent speed. In addition, the road
surfacing would be improved from 80% to 100% bituminous surfacing, which was likely to
have a positive impact on driver stress. By the introduction of further lanes it was considered
likely that there would be more space between vehicles and less need to change lanes,
reducing the fear of potential accidents. The scheme would also give an opportunity to
provide new lighting, signage, screening and other planting, reducing driver stress. The
mounding, environmental screens and landscaping would considerably restrict views from the
road, but would create a more varied highway landscape than before. Overall, the effects
were considered to be moderate positive.
Consultation on Journey Ambience
6.136
No consultation was undertaken specifically for Journey Ambience, however Slip End Parish
Council commented that the view from the M1 is impaired by extensive stretches of wooden
noise barriers.
Evaluation of Journey Ambience
Travellers Views
6.137
Much of the motorway is in cutting which prevents views out, and mounding, planting and
noise barriers have been designed to screen the road from sensitive visual receptors. Some
long, open views of the surrounding landscape have been retained, although these views are
likely to be reduced or filtered as mitigation planting matures. However, the views within the
motorway corridor are varied by the mosaic of different planting schemes and areas of
wildflower grassland. The width of the corridor also varies, adding further variety to travellers
views.
Driver Stress
6.138
As noted in the Traffic section the scheme has reduced congestion and this will have
benefitted driver stress. Although traffic levels have increased slightly, the provision of new
lanes means fewer cars per lane, greater space between vehicles, less need to change
lanes, reduced queues and more consistent speeds(as shown in Section 3, Figures 3.4 and
3.5) which all allieviate driver frustration. Improved signage and lighting have been installed
and will have reduced driver uncertainty and stress. No traffic data is available to determine
whether traffic flows on distributor roads have changed as a result of the scheme.
Traveller Care
6.139
No traveller care facilities provided, as expected.
6.140
A summary of the evaluation compared to the forecast is shown in Table 6.15.
69
M1 Junctions 6a to 10 Widening: One Year After study
Table 6.15 - Summary of Journey Ambience impacts
Origin of
Assessment
Summary of Effects
Assessment
AST
(Forecast)
Driver’s frustration & fear of potential accidents is likely to
reduce. Improved route signs & road information should
reduce the driver’s uncertainty, whilst the improvements in
the view from the road are likely to improve (despite some
new restrictions to views). Overall journey ambience will
benefit from moderate positive impacts. The impacts were
assessed to be beneficial overall.
Beneficial
EST (OYA
Evaluation)
Some long views out preserved, but much of the
motorway is in cutting. Noise barriers, mounding and
planting all reduce views out. Congestion has reduced,
improved signage and lighting installed, and journey times
have improved in line with expectations. .
As expected
70
M1 Junctions 6a to 10 Widening: One Year After study
Key Points from Environment Evaluation
Noise and Local Air Quality

Based on traffic flows which are in line with forecasts it is likely that local noise and air
quality impacts are as expected,
Greenhouse Gases

The increase in opening year carbon emissions is higher than predicted, likely to be due
to differences between the appraisal and evaluation approaches.
Landscape

Mitigation measures provided in line with proposals. One area of offsite planting subject
to vandalism. Lighting of Junction 9 underpass provoked strong negative reactions from
consultees. Too soon to evaluate the establishment of new planting and seeding which
should be reviewed as part of the Five Year After report.
Biodiversity

Mitigation measures provided in line with proposals. Ecological ponds holding water
seasonally . Monitoring suggests that lighting of Nicky Line underpass requires some
changes to reduce impacts on bats. Too soon to evaluate overall effectiveness of
mitigation measures and this should be considered as part of the Five Year After report.
Heritage

Based on the information available it is considered that impacts are as expected.
Publication of the archaeological technical report and archiving of any finds should be
confirmed for the Five Year After report.
Water

Based on the information available it is considered that impacts are as expected and
Environment Agency considered mitigation was provided to a high standard. The
longer term effectiveness of proposed mitigation measures e.g. the vegetative treatment
systems should be reconsidered at Five Years After when As Built drawings for
drainage should be available.
Physical Fitness

No further severance of footpaths as a result of the scheme, and diversions
implemented as expected. On the whole the NMU provision has achieved its
objectives.
Journey Ambience

Some long views out preserved, but much of the motorway is in cutting andnoise
barriers, mounding and planting all reduce views out as expected. Congestion and
therefore driver stress reduced by the provision of new lanes, improved signage and
more reliable journey times.
71
M1 Junctions 6a to 10 Widening: One Year After study
7.
The Accessibility and Integration
Objectives
Introduction
7.1
The Accessibility objective consists of three sub-objectives:
 Option values;
 Severance; and
 Access to the Transport System.
7.2
The Integration Objective consists of the following sub-objectives:
 Interchange with other transport modes; and
 Land Use and Other Government Policies.
7.3
This section will examine each of these sub-objectives in relation to the M1 Junction 6a to 10
scheme.
Accessibility
Option Values
7.4
Option values, as defined in WebTAG, largely relate to measures which will substantially
change the availability of transport services within the study area.
Forecast
7.5
The AST stated that there would be no change to option values as a result of the scheme.
Evaluation
7.6
It is considered that the AST forecast is valid and that no more detailed evaluation would
reveal any changes to options values connected to the scheme.
Severance
7.7
This sub-objective is concerned with those using non-motorised modes, in particular
pedestrians.
Forecast
7.8
For the severance sub-objective the AST states:
‘Due to the overall increase in length of NMU facilities throughout the carriageway widening
scheme, there may be a very slight increase in severance on pedestrians using such
facilities. However, increased severance between community facilities and a reduction in the
amenity level of routes between facilities has been considered unlikely during the operational
phase.’ Score: Neutral.
Evaluation
7.9
The M1 Junctions 6a to 10 Widening – Non Motorised User Context Report outlined a
number of measures that have been implemented to mitigate the severance issues resulting
from the scheme. These are summarised below as follows:
72
M1 Junctions 6a to 10 Widening: One Year After study

Implementation of a cycle path along the A414 (former M10) from the National Cycle
Route 6 (NCR6) at Watford Road to Buncefield Roundabout (East of Hemel Hempstead
adjacent to M1 Junction 8).
-
A site visit was undertaken in July 2010 which confirmed that the cycle path along
the A414 has yet to be implemented. However, the segregated cycle path which runs
parallel to the Collector – Distributor Roads is complete and is shown in Figure 7.1.
Figure 7.1 – Dedicated cycle path near Junction 8

Existing bridges and subways crossing the M1 at seventeen locations have been
extended or replaced in their existing location or adjacent to their existing location.
-
A successful example of this has been the provision made National Cycle Network
57 to cross the M1. This route consists of a dismantled railway (the ‘Nicky Line)
between Junctions 7 and 8 and the new tunnel (shown in Figure 7.2) includes high
levels of lighting throughout to increase perception of security.
Figure 7.2 – M1 Underpass serving National Cycle Network 57

Although there have been some diversions of footpaths and bridleways, none have been
severed completely as a result of the scheme.
73
M1 Junctions 6a to 10 Widening: One Year After study
It is noted that when the M1 was originally constructed in the 1950’s, a number of footpaths
and roads were severed, restricting movements across the M1. The recent widening of the
M1 does not create any further severance so the impact is neutral as expected.
Access to the Transport System
7.10
WebTAG states that access to the transport system is strongly influenced by the two key
variables introduced at the start of this section, i.e. access to a private car and proximity to a
public transport service.
Forecast
7.11
For the Access to the Transport System sub-objective, the AST states:
‘No direct proposals (not applicable to road schemes.)’ Score: Neutral.
Evaluation
7.12
This scheme has had no direct impact on public transport provision, therefore the AST
assessment of neutral impact is considered to be valid in this instance.
Integration
Transport Interchange
Forecast
7.13
The AST states:
‘The opportunity to use public transport will exist at current levels’ Score: Neutral.
Evaluation
7.14
The scheme has not had an impact on the provision of transport interchange facilities
therefore a neutral impact has been observed as expected.
Land Use and Other Government Policies
Forecast
7.15
For both Land Use and Other Government Policies, the AST predicted a neutral impact.
Evaluation
7.16
This section undertakes a review of the relevant local, regional and national policy documents
applicable to this scheme in order to determine if the main objectives outlined in these
policies closely align to the achievements of the M1 scheme. In summary, the scheme
integrates well with the objectives set out in local, regional and national policies as
expected.
M1 Junctions 1 to 19 and M10 Management Strategy (March 2006)
The M1 Route Management Strategy (RMS) led to the development of a number of Route
Outcomes which set out what the HA seek to obtain over the ten year period of the RMS. The
list below shows selected Route Outcomes, and briefly explains how the M1 Junctions 6a to
10 scheme has contributed to them:

RO1 – Improve journey time reliability along the M1 (Junction 1-19)
- As shown in Section 5 of this report.

RO2 – Improve information to road users
- Increased provision of Variable Message Signs (VMS)
74
M1 Junctions 6a to 10 Widening: One Year After study

RO3 – Reduce accidents at the M1 junctions and/or links, including the M10
- As shown in Section 4.
RO13 – Facilitate the development of the Milton Keynes and South Midlands (MKSM)
growth area whilst safeguarding the operation of the trunk road network.
- As shown by increased capacity and improvement in journey times and reliability.
RO17 – M1 Junction 7 to 8 – Reduce the conflict of northbound traffic weaving and
congestion.
- This would have been reduced by the provision of the local new routes between
junction 7 and 8 as part of the scheme which segregates local and strategic traffic.


Hertfordshire Local Transport Plan (2006-2007 to 2010-2011)
7.17
The Hertfordshire Local Transport Plan (LTP) contains a number of polices that are relevant
to the scheme:

7.18
To improve safety for all by giving the highest priority to minimising the number of
collisions and injuries occurring as a result of the transport system;

To develop and efficient, safe, affordable and enhanced transport system which is
attractive, reliable, integrated and makes best use of resources; and

To ensure that the transport system contributes towards improving the efficiency of
commerce and industry and the provision of sustainable economic development in
appropriate locations.
The improved journey times and reduction in accidents since the scheme opened provides
evidence that the above objectives have been met.
Key Points from Accessibility and Integration Evaluation
Accessibility

It is considered that the AST forecast for option values is valid and that no more detailed
evaluation would reveal any changes connected to the scheme.
 This scheme has had no direct impact on public transport provision, therefore the AST
assessment of neutral impact is considered to be valid in this instance.
 The scheme has maintained the existing crossing facilities facilitating movement across
the M1. The severance impact is therefore neutral as expected.
Integration
 The scheme has not had an impact on the provision of public transport interchange as
expected.
 The scheme integrates well with the objectives set out in local, regional and national
policies as expected.
75
M1 Junctions 6a to 10 Widening: One Year After study
8.
Appraisal and Evaluation Summary
Tables
Appraisal Summary Table (August 2007)
8.1
The Appraisal Summary Table (AST) is a brief summary of the main economic, safety,
environmental and social impacts of a highway scheme. Table 8.1 presents the AST for the
M1 Junction 6a to 10 widening scheme prepared at the time of the appraisal.
8.2
The AST presents a brief description of the scheme, a problem statement detailing the
problems that the scheme planned to address, and makes an assessment of the schemes
predicted qualitative and quantitative impacts against the following core NATA (New
Approach to Appraisal) objectives:





Environment – an estimate of scheme impact upon factors such as noise, local air
quality, landscape, biodiversity, heritage and water;
Safety – measured reduction in the number and severity of accidents and qualitative
assessment of impacts on security;
Economy – estimated impact of the scheme upon Journey Times, Vehicle operating
Costs, scheme cost and journey time reliability;
Accessibility – a review of scheme impact upon access to the public transport network,
community severance and non-motorised user impact; and
Integration – a description of how a scheme is integrated with wider local planning,
regional and national policy objectives.
Evaluation Summary Table
8.3
The Evaluation Summary Table (EST) was devised for the POPE process, to record a
summary of the outturn impacts for the NATA objectives, compared to the predictions in the
AST.
8.4
Drawing on results presented in this report, Table 8.2 presents the EST for the M6 Junction
6a to 10 widening. An assessment for each of the objectives at the One Year After stage is
given. Where possible, the format of the EST mirrors the appearance and process of the
AST to enable direct comparison between the two.
76
M1 Junctions 6a to 10 Widening: One Year After study
Table 8.1 – Appraisal Summary Table (August 2007)
Scheme Name: M1 J6a to 10
Widening
Integration
Access
Economy
Safety
Environment
Obj
Description: Widening existing M1 between Junction 6a and 10 to D4M in both directions. Addition of D2 distributer roads between junctions 7 and 8.
Sub-Objective
Problems: Severe congestion and delay and high
accident occurrence.
PVC
to
Public
Accounts: £290m
Quantitative Impacts
Assessment
Qualitative Impacts
Noise
The assessment has found that increases in noise levels of up to 3dB would be experienced at 10 properties. The assessment has also found that 408 properties would gain decreases of up
to 15dB On the basis of the assessment, no additional means of mitigation are considered necessary other than those that have already been incorporated into the scheme proposals.
Estimated Population Annoyed Do Minimum: 191
Estimated Population Annoyed Do Something: 157
Population Annoyed DS
minus DM -34
Local Air Quality
A negligible deterioration in local air quality is expected with the scheme in place. Changes in concentrations at properties within 200 metres of the scheme are well below the significance
criteria for NO2 & PM10 (2 & 1 micrograms per cubic metre respectively, as an annual mean) & are unlikely to be measurable. Changes in air quality are expected due to the increase in traffic
volume & speed.
Number of Properties with an improvement: 1
Number of Properties with no change: 0
Number of Properties with a deterioration: 20
Overall PM10 score: 7
Overall NO2 score:17
Greenhouse Gases
Emissions of CO2 are estimated to increase with the scheme in place by around 9% in the opening year (2008).
Increases are due to the increase in the overall length of the route from J 6 to 10 with the scheme in place. The number of vehicles on this part of the road network is expected to increase with
the scheme in place.
Compared to the existing case (2001) there is an increase
of 17% (27,500 tonnes) of CO2 with the scheme in 2008.
There is an increase of 9% (16,000) tonnes in 2008 with
the scheme compared to the do-minimum situation.
Total change in CO2
emissions due to
scheme in the opening
year is an increase of
16,000 tonnes per year.
Landscape
The M1 is currently a prominent feature, cutting across the largely agricultural landscape; the improvements will initially result in a loss of existing vegetation, landtake of largely agricultural l&
& increased visibility of the motorway & associated engineering elements. Proposed mitigation measures including mounding & planting will reduce impacts, including offering improvements
when compared to the existing situation. Mitigation measures will also help to integrate the motorway, including the associated engineering structures, with the wider landscape character &
improve views from adjacent visual amenity receptors including Redbourn.
N/A
Slight Beneficial
Townscape
N/A
N/A
Neutral
Heritage of Historic
Resources
The scheme will only affect known archaeological sites partially - disturbing the surrounds of the SAM, but not the designated area, & only elements of the 20th century landscape. Impacts of
the scheme on buildings, Conservation Areas & Parks will be indirect (on their setting), & no greater than those posed by the current road. Impact on buried archaeological remains will be
major, but these remains (if found to be present) are not likely to be of more than regional importance.
N/A
Slight Adverse
Biodiversity
The impacts of the widening scheme have been judged on the basis that many of the habitats adjacent to the motorway have already been bisected & degraded in quality & that further
damage will be limited. The majority of the impacts have been assessed as being slight adverse on this basis. Impacts on protected species are envisaged to be negligible. Proposed
mitigation such as replacement of bat roosts, re-planting of native species rich hedges, creation of species-rich grassland& & the creation of wildlife ponds near J 8 should go some way to
addressing the impacts of the scheme.
N/A
Slight Adverse
Water
The use of current good practices in accordance with Environment Agency guidelines during the construction phase & the implementation of Vegetative Treatment Systems during the
operational phase should significantly reduce any potential impact to controlled waters. The scheme will include improvements to: pollution control, storm water attenuation, discharge to
groundwater & will reduce the risk of accidental spillage.
N/A
Slight Beneficial
Physical Fitness
Crossing facilities & Public Rights of Way will be maintained & improved/replaced when disrupted. Other improvements have also been incorporated as part of the scheme. Overall the
proposals suggest that journey distances by non-motorised users will increase by approximately 800m equating to an additional journey time for pedestrians of 10 minutes across the scheme.
The scheme is unlikely to reduce the number of walking/cycling trips made once the scheme has been implemented. Any increase in physical activity is unlikely to be significant enough to
contribute to the overall health strategy.
N/A
Neutral
Journey Ambience
Driver’s frustration & fear of potential accidents is likely to reduce. Improved route signs & road information should reduce the driver’s uncertainty, whilst the improvements in the view from the
road are likely to improve (despite some new restrictions to views). Overall journey ambience will benefit from moderate positive impacts.
N/A
Beneficial
Accidents
Accident rates based on observed data are relatively high, whereas default rates have been assumed for the scheme. Hence the high level of accident cost savings.
Over 60 years:
Central Growth
PIA’s
16,600
High Growth
N/A
Slight
26,889
N/A
Serious
1,520
N/A
Fatal
253
N/A
PVB: £773.4m
Personal Security
Not really applicable although security will be slightly enhanced by the improved flow for vehicles thus reducing the frequency of stationary traffic & the opportunity for incidents.
Slight Beneficial
Public Accounts
Investment cost of scheme is £276.3m. Additional cost of indirect taxation is £17.2m, maintenance cost saving is £3.4m. Overall cost is £290m.
Central Government PVC: £290m
Local Government PVC: £0m
PVC: £290m
Business Users
Business User travel time benefits of £803.3m, no VOC benefits.
Business Users PVB: £803.3m
PVB: £803.3m
Consumer Users
Consumer travel time benefits £373.9m, VOC benefits of £53.8m.
Consumer Users PVB: £427.7m
PVB: £427.7m
Reliability
Based on preliminary INCA results additional benefits in excess of £500 million may be accrued to the scheme due to improved travel time reliability & the reduction in incidents.
Wider Economic
Impacts
No issues relating to designated regeneration areas.
N/A
No
Option Values
Not directly affected by the scheme (not applicable to road schemes).
N/A
PVB: £0m
Severance
Due to the overall increase in length in NMU facilities throughout the carriageway widening scheme, there may be a very slight increase in severance on pedestrians using such facilities
however increased severance between community facilities & a reduction in the amenity level of routes between facilities has been considered unlikely during the operational phase.
Access to the
Transport System
No direct proposals (not applicable to road schemes).
Trans Interchange
The opportunity to use public transport will exist at current levels.
Neutral
Land-use Policy
Proposal complies with elements of local, regional & national policy namely those which specifically support the M1 widening scheme to improve capacity of the strategic road network, reduce
congestion & improve local accessibility. Conflicts with a range of environmental & sustainability policies at all three policy spheres to a certain degree. However, the identified impacts on
biodiversity, flora & fauna, on known archaeological remains & landscape will be mitigated where possible, through the incorporation of detailed mitigation measures into the scheme design &
as such, accord with local planning policy objectives. Through detailed ecological & landscape proposals, the scheme will be sympathetically integrated into the surrounding landscape.
Neutral
Other Gov’t Policies
With mitigation measures in place during the construction & operational phase, the widening scheme would broadly assist in meeting the policy objectives of the main Government
Departments & the main Government Advisory bodies: Environment Agency, English Heritage, Countryside Agency & English Nature. However, the scheme will conflict with the overarching
environmental objectives in conserving & enhancing biodiversity, landscape & the historic environment & those seeking a reduction in the dependence on road transport.
Neutral
High Beneficial
Neutral
N/A
77
Neutral
M1 Junctions 6a to 10 Widening: One Year After study
Table 8.2 – Evaluation Summary Table (EST)
Integrati
on
Accessibility
Economy
Safety
Environment
Obj
Sub-Objective
Qualitative Impacts
Quantitative Impacts
Noise
Mitigation measures appear to have been implemented as expected. Based on traffic flows, which are within +25%` / -20% of
predictions, it is likely that the local noise climate due to traffic is as expected.
N/A
Local Air Quality
Based on traffic flows, which are within +/-10% of predictions, it is likely that the local air quality due to traffic is as expected.
N/A
Likely to be as expected.
N/A
Greenhouse Gases
Increased emissions due to increased speeds and traffic volumes.
Increase of 16% (14,500
tonnes of carbon)
N/A
Landscape
Mitigation measures generally provided in line with proposals. One area of offsite planting subject to vandalism. Underbridge
lighting at Junction 9 resulted in strong negative comments from consultees. Too soon to evaluate screening value or
establishment of new planting and seeding, and should be reviewed as part of the Five Year After report.
Generally as expected at
this OYA stage.
Townscape
N/A
N/A
N/A
Publication of the post-excavation technical report and archiving of any finds should be confirmed at FYA. Effects on
Conservation Areas as expected. With regard to the setting of listed buildings and screening of the Aubreys SAM, the
effectiveness of proposed mitigation planting should be assessed at FYA.
N/A
N/A
Biodiversity
Mitigation measures provided for species and habitats. Too soon to evaluate effectiveness and should be reviewed as part of
the Five Year After report. Bats, badgers, calcareous grassland, bluebells, ecological ponds and bird boxes monitoring report
received. Monitoring of most species to continue until 2013. Lighting of Nicky Line underpass requires amendment to reduce
impacts on bats. Ecological ponds not yet effective as only holfding water seasonally and not yet revegetated.
Water
POPE is not aware of any pollution incidents or that the mitigation measures are performing other than as expected. . The
longer term effectiveness of drainage measures should be re-considered at Five Years After
N/A
No further severance of footpaths as a result of the scheme, and diversions implemented as expected. . One cycleway not
yet constructed and should be considered at Five Years After. On the whole the NMU provision has achieved its objectives.
N/A
Physical Fitness
N/A
Journey Ambience
Some long views out preserved, but much of the motorway is in cutting. Noise barriers, mounding and planting all reduce
views out. Congestion and therefore driver stress likely to have been reduced by the provision of new lanes. Improved
signage and lighting installed to reduce driver stress. Journey times have improved in line with expectations. .
Heritage of Historic
Resources
Accidents
Re-forecast accident savings almost exactly the same as forecast.
Assessment
Likely to be as expected.
As expected
Likely to be as expected
based on the
information available at
this OYA stage
As expected
As expected
As expected
Saving of 222 PIA’s per year.
As expected
N/A
As expected
Outturn journey time savings in excess of
£1billion.
As expected
Personal Security
The impact on personal security is slight beneficial as expected due to improved journey time reliability and increased CCTV
provision.
Transport Economic
Efficiency
Journey time impacts similar to those forecast
Reliability
Analysis of the standard deviation of journey times shows that journey time reliability has improved since scheme opening.
N/A
As expected
Wider Economic Impacts
The scheme has contributed to the growth aspirations of the MKSM area by providing additional capacity and improved journey
times on the main strategic highway through the area.
N/A
Not Appraised (Evaluated
as beneficial)
Option Values
The scheme has not changed the availability of transport services in the vicinity of the scheme.
N/A
As expected
Severance
The scheme has not severed any footpaths or bridleways, crossing provision has been maintained, and extension of the existing
cycle network along the A414 (former M10) was constructed.
N/A
As expected
Access to the Transport
System
No direct change in public transport provision as a result of the scheme.
N/A
As expected
Transport Interchange
The scheme has not had an impact on the provision of transport interchange facilities.
N/A
As expected
Land-use Policy
The scheme integrates well with the objectives set out in local, regional and national policies.
N/A
As expected
Other Gov’t Policies
78
M1 Junctions 6a to 10 Widening: One Year After study
79
M1 Junctions 6a to 10 Widening: One Year After study
9.
Conclusions
9.1
To conclude this report, this section summarises how the scheme is meeting its scheme
specific impacts, and assesses those impacts against forecast.
Success against Objectives
9.2

NATA objectives: Impacts are assessed against the Government’s five objectives for
transport: environment, safety, economy, accessibility and integration; and

Scheme specific objectives.
The scheme’s success against the NATA objectives was presented in the previous section in
the Evaluation Summary Table (Table 9.1).
Scheme Specific Objectives
9.3
Drawing upon information presented in this report, a summary of the scheme’s success
against the specific objectives listed previously in Section 1 of this report is provided in Table
9.1.
Table 9.1 – Success against Scheme Objectives
Source
AST
(August
2007)
9.4
Objective
Success
Reduce congestion
Increased capacity, reduced journey
times, and improved reliability indicate
that congestion has been reduced as a
result of the scheme.

Improve journey time
reliability
An analysis of the standard deviation of
before and after opening journey times
shows that journey time reliability has
improved as a result of the scheme.

Reduce accidents
Based on the limited amount of post
opening data available, the evidence
suggests that the scheme has been very
successful in reducing accidents.

In summary, the results in Table 9.1 show that based on the data available at this one year
after stage, the M1 Junction 6a to 10 widening scheme is achieving all of its objectives.
Conclusions
9.5
A summary of the main impacts of the scheme, and potential reasons for any differences is
contained in Figure 9.1.
80
M1 Junctions 6a to 10 Widening: One Year After study
Impact
Potential Reasons for Difference
Figure 9.1 – Summary of the Main Scheme Impacts Compared to Forecast
Five Years After Study
9.6
The Five Years After Study due to be undertaken in 2013 will follow a similar structure to this
One Year study setting out a comparison of the forecast and outturn impacts of the scheme
against each of the NATA objectives (and sub-objectives) five years after opening. This will
examine whether the findings of this study are continuing.
9.7
The Five Year After Study will, however, allow a more detailed analysis of the following:


Results from the accident analysis are likely to be more conclusive than those recorded
at the one year after stage;
The environmental evaluation will focus more closely on the effectiveness of mitigation
measures which should me more evident at that stage; and

9.8
A qualitative assessment of the wider economic impacts of the scheme.
It should, however, be noted that any evaluation at Five Year After stage will not represent a
true ‘like with like’ comparison with the scheme appraisal due to the recent implementation of
controlled motorway with variable advisory speed limits.
81
M1 Junctions 6a to 10 Widening: One Year After study
Appendix A - Glossary of Terms
82
M1 Junctions 6a to 10 Widening: One Year After study
The following table details the acronyms and specialist terms used within the context of this report.
Term
Definition
AADT
Annual Average Daily Traffic. Average of 24 hour flows, seven days a week, for
all days within the year.
AAWT
Annual Average Weekday Traffic.
Friday) only.
Accessibility
Accessibility can be defined as ‘ease of reaching’. The accessibility objective is
concerned with increasing the ability with which people in different locations, and
with differing availability of transport, can reach different types of facility.
AM
denoting the morning peak period
AST
Appraisal Summary Table. This records the impacts of the scheme according to
the Government’s five key objects for transport, as defined in DfT guidance
contained on its Transport Analysis Guidance web pages, WebTAG
ATC
Automatic Traffic Count, a machine which measures traffic flow at a point in the
road.
AWT
Average Weekday Traffic. Average of Monday to Friday 24 hour flows.
BCR
Benefit to Cost Ratio
Capacity
The maximum hourly lane throughput.
COBA
COst Benefit Analysis – a computer program which compares the costs of
providing road schemes with the benefits derived by road users (in terms of time,
vehicle operating costs and accidents), and expresses the results in terms of a
monetary valuation. The COBA model uses the fixed trip matrix.
Controlled
Motorway
As AADT but for five days, (Monday to
A motorway with an automatic speed-control environment based on MIDAS, and
responds to changes in traffic flows and congestion levels. The speed limits
imposed may be advisory or mandatory depending on the regulatory restrictions
imposed.
Note this is not the same as a Managed Motorway which includes hard shoulder
running in addition to the features of a controlled motorway.
CRF
Congestion Reference Flow - AADT flow at which a road is likely to be
congested in the peak periods of an average day.
DfT
Department for Transport
Discounting
Discounting is a technique used to compare costs and benefits that occur in
different time periods and is the process of adjusting future cash flows to their
present values to reflect the time value of money, e.g. £1 worth of benefits now is
worth more than £1 in the future. A standard base year needs to be used which is
2002 for the appraisal used in this report.
EST
Evaluation Summary Table. In POPE studies, this is a summary of the
evaluations of the TAG objectives using a similar format to the forecasts in the
AST.
HGV
Heavy Goods Vehicle.
Highways Agency
An Executive Agency of the Department for Transport, responsible for operating,
maintaining and improving the strategic road network in England.
INCA
Incident Cost Benefit Assessment is a spreadsheet application for calculating
incident related delays and travel time costs, and for quantifying the benefits that
83
M1 Junctions 6a to 10 Widening: One Year After study
may arise from remedial measures to reduce their impact.
IP
Inter Peak, the time between the AM and PM peaks
JTDB
Journey Time Database – For the Highways Agency’s core network. Consists of
junction to junction time segments for each 15 minute period.
KSI
Killed or Seriously Injured
MIDAS
Motorway Incident Detection and Automated Signalling is a distributed
network of traffic sensors, which are designed to set variable message signs and
speed limits with little human intervention.
NILO
National Incident Liaison Officer. A department within the HA responsible for
monitoring and recording incidents occurring on the strategic highway network and
disseminating incident-related information to the correct staff within the Highways
Agency and their partners, such as the traffic media.
PIA
Personal Injury Accident. A road traffic accident in which at least one person
required medical treatment.
PIA/mvkm
PIA/mvkm is the number of PIAs per million vehicle kilometres where ‘vehicle
kilometres’ are the number of vehicles using a section of the road multiplied by the
length of the road.
PM
Evening peak period
POPE
Post Opening Project Evaluation, before & after monitoring of all major highway
schemes in England.
Screenline
An imaginary line drawn across a transport corridor used to determine flows
between areas on either side. Each road crossed by the screen line is monitored
by a traffic count (ATC).
Severance
Community severance is the separation of adjacent areas by road or heavy traffic,
causing negative impact on non-motorised users, particularly pedestrians.
SSSI
Site of Special Scientific Interest
STATS19
A database of injury accident statistics recorded by police officers attending
accidents
TRADS
Traffic Flow Data System
Vehicle hours
Vehicle hours refers to the total time spent by all vehicles using a road and is
expressed normally as a yearly value. For example, if 10,000 vehicles a day used
a route with a 6 minute journey time, then the route’s vehicle hours for the year
would be 365,000.
VOT
Value Of Time
vpd
Vehicles Per Day
webTAG
Department for Transport’s website for guidance on the conduct of transport
studies at http://www.webtag.org.uk/
84
M1 Junctions 6a to 10 Widening: One Year After study
Appendix B – Environmental Information
Requested
85
M1 Junctions 6a to 10 Widening: One Year After study
Table B.1 – Environmental Information Requested
Requested Information
Information Provided
Environmental Statement
Not available in full although the NTS for
the 1994 was available
Appraisal Summary Table
Provided by HA version
Any amendments, updates or addendums to the
ES or any relevant further studies or reports. Any
significant changes to the scheme since the ES.
Detailed Scheme Report (DSR), ecology,
heritage and noise update reports
provided
'As Built' drawings for landscape, ecological
mitigation measures, drainage, fencing,
earthworks etc.
Landscape and Ecology As Built drawings
provided
Landscape and Ecology Management Plans
LEAP provided
Construction Environment Management Plan
CEMP provided
Relevant contact names, of people with
knowledge of the scheme, at:
Provided by HA
Drainage As Built drawings not provided
the statutory consultees (Environment Agency,
English Heritage and Natural England);
the local authorities;
the designer or environmental coordinators for
the scheme and for the MAC; and,
any other relevant specialist consultees that were
contacted.
Archaeological reports (popular and academic)
Draft unpublished Post Excavation
Archaeology Report provided, the
technical archaeology report should be
available at FYA
List of Part 1 Claims regarding noise, air quality
or lighting (from HA National Part 1 Team)
Too early in the claims process and will be
provided for 5YA report
Results of any post opening survey or monitoring
work e.g. ecology surveys, water quality surveys
pre- and post- construction
Ecology surveys received
Animal mortality data, pre and post scheme
construction
Provided by MAC
Any scheme newsletters or publicity material for
the scheme
Available on HA web page
Copy of the Non-motorised User (NMU) post
opening survey
Not undertaken
86
M1 Junctions 6a to 10 Widening: One Year After study
Appendix C – Visual Impact of Scheme
87
M1 Junctions 6a to 10 Widening: One Year After study
Waste Management, Appspond Lane:
DSR baseline: design year effect, slight adverse
1 year after: noise barrier reduces view of traffic, gantry clearly visible.
88
M1 Junctions 6a to 10 Widening: One Year After study
Beechtree Cottage
DSR baseline: design year effect, possibly moderate adverse
1 year after: carriageway closer to property, but screening vegetation retained.
89
M1 Junctions 6a to 10 Widening: One Year After study
Hill End Cottage
DSR baseline: design year effect, slight adverse
1 year after: some screening vegetation lost, but view relatively unchanged.
90
M1 Junctions 6a to 10 Widening: One Year After study
Dwelling at the Breakspears
DSR baseline: design year effect, large adverse
1 year after: considerable screening vegetation lost, noise barrier/screen installed.
91
M1 Junctions 6a to 10 Widening: One Year After study
The Aubreys Fort SAM
DSR baseline: design year effect, moderate adverse
`
1 year after: some screening vegetation lost. (Photograph taken from slightly different location).
92
M1 Junctions 6a to 10 Widening: One Year After study
PROW 20, Flamstead
DSR baseline: design year effect, slight adverse
1 year after: distant view, relatively unchanged.
93
M1 Junctions 6a to 10 Widening: One Year After study
Church Road, Slip End
DSR baseline: design year effect, slight adverse
1 year after: considerable screening vegetation lost, noise barrier in place.
94
M1 Junctions 6a to 10 Widening: One Year After study
Playing Field at Slip End
DSR baseline: design year effect, slight adverse
1 year after: some screening vegetation lost.
95
M1 Junctions 6a to 10 Widening: One Year After study
Dwellings east of Pepsal End Lane, Pepperstock
DSR baseline: design year effect, slight adverse
1 year after: considerable mature screening vegetation lost, noise barriers installed.
96
M1 Junctions 6a to 10 Widening: One Year After study
Dwellings in the vicinity of The Beeches
DSR baseline: the property occupies an elevated position close to the motorway. A deciduous hedge provides some screening in summer.
No baseline photograph in DSR.
Design year effect, slight adverse.
1 year after: Noise barriers installed, proposed planting in place. (Photograph taken from end of The Beeches driveway, facing north east).
97
M1 Junctions 6a to 10 Widening: One Year After study
Nicholls Farm
DSR baseline: the motorway runs partially in a vegetated cutting and close to grade past the farm, the vicinity of which affords partial views of the motorway.
Includes a Grade II listed building, the setting of which is adversely affected by the proximity of the motorway.
No baseline photograph in DSR.
Design year effect, substantial adverse.
1 year after: Proposed planting in place, including offsite planting of standard trees.
98
M1 Junctions 6a to 10 Widening: One Year After study
Norringtonend Farm
DSR baseline: in summer the motorway is screened from view by the cutting and associated woody vegetation. Includes Grade II listed building, but faces
away from motorway.
No baseline photograph in DSR.
Design year effect, moderate adverse.
1 year after: Proposed planting in place, gantry clearly visible.
99
M1 Junctions 6a to 10 Widening: One Year After study
PROW 23, Flamstead
DSR baseline: clear views of the motorway where the footpath crosses open fields.
No baseline photograph in DSR.
Design year effect, substantial adverse.
1 year after: Clear views of motorway from footpath.
100