DESIGN MANUAL FOR ROADS AND BRIDGES
volume 0
section 2
INTRODUCTION AND
GENERAL
REQUIREMENTS
GENERAL GUIDANCE
Part 3
gd 04/12
Standard for Safety Risk
Assessment on the Strategic
Road Network
SUMMARY
This Standard sets out the approach which must be
applied in all administrative and technical aspects
when designing, operating and constructing for the
strategic road network, where safety should be a
consideration. It updates, and clarifies, requirements
and guidance for addressing safety risks. This includes
planning, preparing, designing and constructing
highway works, maintenance, demolition and
improvements, projects and schemes, and when
revising Agency technical standards, specifications
and requirements. This Standard sets out the HA
requirements for managing safety and as such it does
not provide legal advice or guidance. This document
only applies to England’s Strategic Road Network.
instructions for use
This Standard is to be incorporated in the Manual.
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November 2012
design manual for roads and bridges
GD 04/12
Volume 0, Section 2,
Part 3
the highways agency
Standard for Safety Risk
Assessment on the
Strategic Road Network
Summary:
This Standard sets out the approach which must be applied in all administrative
and technical aspects when designing, operating and constructing for the strategic road network, where safety should be a consideration. It updates, and clarifies, requirements and guidance for addressing safety risks. This includes planning, preparing, designing and constructing highway works, maintenance, demolition and improvements, projects and schemes, and when revising Agency technical standards, specifications and requirements. This Standard sets out the HA requirements for managing safety and as such it does not provide legal advice or guidance. This document only applies to England’s Strategic Road Network.
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November 2012
DESIGN MANUAL FOR ROADS AND BRIDGES
volume 0
section 2
INTRODUCTION AND
GENERAL
REQUIREMENTS
GENERAL GUIDANCE
Part 3
gd 04/12
Standard for Safety Risk
Assessment on the Strategic
Road Network
Contents
Chapter
Part 1
1. Introduction and Use of this Document
2. Defining the People at Risk
3. Duties and Responsibilities
4. General Principles
Part 2
5. Principles of Safety Risk Assessment and Control
6. Technical Requirements
7. Roles, Responsibilities and Competence
8. Glossary
9. References
10.
Abbreviations and Acronyms
Annexes
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Annex A
Generic Safety Risk Analysis Methods
Annex B
Average Road User Safety Risk on
GB Roads
Annex C
Hazard Identification and Risk
Assessment Tool
Annex D
Cost Benefit Tool
Chapter 1
Introduction and Use of this Document
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Part 1
1. Introduction and use of this document
1.1
This standard is presented in two parts.
Part 1 provides an overview of the Highways Agency’s
(Agency) safety risk management framework and
sets the context within which safety risk management
decisions are taken in accordance with this standard.
Part 2 takes this information and translates it into a
specific safety risk decision making framework for safety
risk assessment and control across all of the populations
affected by the Strategic Road Network (SRN).
Background
1.2 On 28 February 2001 a vehicle came off the
M62 motorway at Great Heck, near Selby, ran down
the embankment and onto the East Coast Main Line,
where it was struck by a passenger train. The train was
derailed and then struck by a freight train travelling in
the opposite direction. Six passengers and four staff
on the trains were killed. The driver of the vehicle was
found guilty of causing the deaths of 10 people by
dangerous driving.
1.3 The Health and Safety Executive (HSE)
investigated the circumstances that led to the incident
and their report made it clear that the accident had
resulted from a highly unlikely and unpredictable chain
of events. However, the Government was concerned
about the general issues this crash raised and asked for a
wider investigation into the accidental incursion of road
vehicles onto the railway. This investigation identified
specific actions related to road/rail incursions as well
as more general and fundamental issues to do with the
methods used by the Agency to assess and record safety
risks, and the documentation of the decision processes
linked to the management and or treatment of these.
1.4 Since this time the Agency has developed a more
transparent approach to safety risk management and has
been working towards the embedment of this approach
across all of the various areas of the business.
Objectives
1.5 Agency projects have traditionally used a
prescriptive approach to demonstrating safety, relying
on adherence to detailed standards. These standards
November 2012
are based on research, pilot activities and many
years of experience, capturing the necessary safety
risk mitigation properties. However, this approach is
becoming less appropriate for the more complex and
innovative systems now being installed on the SRN.
The Agency has been successful in improving safety,
but this means that future improvements in safety will
be much more difficult to realise and thus a more refined
approach to safety decision making is required on
highway projects going forward.
1.6 This standard updates and clarifies requirements
and guidance for addressing safety risks. It introduces
the concept of ‘trade off’ and describes how safety risk
tolerance can be used to optimally balance safety risk
between affected populations. This approach is not new
and the principle of ‘trade off’ is accepted by the HSE.
The ‘trade off’ principle has been applied:
•
in road over rail situations;
•
in the development of Existing Motorway
Minimum Requirements;
•
in Managed Motorway requirements;
•
in the Department for Transport (DfT) ‘Managing
the accidental obstruction of the railway by road
vehicles’ report; and
•
in Aiming for Zero projects to improve/benefit
worker safety.
1.7 A key requirement of this standard is that
appropriate safety risk assessment, evaluation and
management is undertaken to inform all activities,
projects and decisions. This includes ensuring that
the safety risk impacts for different populations
(see Chapter 2 ‘Defining the People at Safety
Risk’) that the Agency has a responsibility for,
along with their safety risk exposure and safety risk
tolerance, are taken into account. It also requires
that documentation is kept which evidences the
decision making process.
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Chapter 1
Introduction and Use of this Document
Scope
1.8 This Standard has been developed in consultation
and with the agreement of devolved administrations.
It deals with all safety risk management activities in
relation to the design of the SRN in England only. It is for
other highway authorities and devolved administrations
to choose whether to adopt all or part of this standard.
1.9 This Standard does not provide guidance
on operational safety risk decision making such as
Traffic Officer dynamic risk assessment processes.
Operational decisions will need to have regard
to the safety risk control measures specified by
designers who use this Standard.
1.10 This Standard is not a legal interpretation of
the legislation it refers to; as such it does not provide
legal advice or guidance. In the event of queries on the
applicable law, independent legal advice should be sought.
Mandatory Sections
1.11 Sections of this document containing
mandatory requirements are identified by
highlighted boxes. These requirements are
mandatory and no departures from this standard
will be accepted. Appropriate safety risk
assessment, evaluation and management must
be undertaken so that a decision can be made
on the basis of what is reasonably required. In
circumstances where reliable data is limited or
not available the principles of the standard must
still be applied; in these instances the professional
judgment of a competent person will be required
(please see Chapter 6 for more details). The text
outside boxes contains advice and explanation,
which is commended to ‘users’ for consideration.
Implementation
1.12 This Standard gives the approach which
must be applied forthwith by all Agency staff and
supply chain, in all administrative and technical
aspects when designing operating and constructing
the SRN, where safety should be a consideration.
This includes planning, preparing, designing
and constructing highway works. This includes
maintenance, demolition and improvements, projects
and schemes, and when revising Agency technical
standards, specifications and requirements.
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1.13 Application of this standard will ensure that
safety risk and investment decisions affecting the
SRN are made:
•
Consistently – so that similar decisions, made
by different people at different times, in different
locations result in comparable outputs.
•
Aligned – so that full account is taken of Agency
targets, objectives, duties, responsibilities and
policies.
•
Robustly – so that decisions are demonstrated
by evidence or expert advice and are auditable.
•
Value – so that decisions made represent value
for money (VfM).
•
Transparently – so it is clear why, and how,
a particular decision was taken.
1.14 The processes referenced in this standard should
be applied pragmatically and avoid the creation of
a burdensome and bureaucratic process. Instead the
process should be viewed as an opportunity to simply
and effectively record the best judgements of the
professionals involved.
1.15 The guidance contained in this standard sets out
existing process and best practice that the Agency and
its representatives should already be following.
1.16 It should be read in conjunction with the Design
Manual for Roads and Bridges (DMRB) and the
Agency’s Health and Safety Management System
contained within the Management Arrangements for
Health and Safety (MAHS), where advice and guidance
including policy statements for traffic officers, workers,
construction workers and other parties can be found.
For advice/support and access to MAHS please contact
the HA team responsible for Health and Safety.
Equality Impact Assessment
1.17 The guidance in this standard has been developed
to ensure that all persons affected by the SRN and
thereby exposed to safety risk are considered. The
safety risk assessment process will itself identify any
disadvantaged or vulnerable people and appropriate
control measures are mandated.
Definitions and Abbreviations
1.18 Terms and references relevant to this standard are
dealt with in Chapters 9, 10 and 11 of this document.
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Chapter 2
Defining the People at Safety Risk
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2. Defining the people at safety risk
2.1 Highway authorities have specific legal duties
and responsibilities that are prescribed by various acts
and regulations; thus a balanced safety risk assessment
methodology that takes account of these must be put
in place.
2.2 To illustrate transparent compliance with its
legal duties and responsibilities relating to safety risk
the Agency has developed the safety risk decisionmaking process described in this Standard. This
process must be applied in a manner that enables
the Agency to do what is reasonably required to
manage, operate and maintain the SRN within the
legal duties of the Secretary of State for Transport.
2.3 There are four populations that must be
taken into account when considering what is
reasonably required to manage their safety risk
exposure. These populations are defined on the
left hand side of Table 1 below and then these
populations have been brigaded for the purposes
of this standard into three groups as illustrated on
the right hand side of the table. These definitions
shall be applied throughout this document and in
its interpretation.
Population 1 – People directly employed by the Agency and who work on the SRN,
e.g. Traffic Officers.
Population 2 – People in a contractural relationship with the Agency, including Agency
National Vehicle Recovery Contract operatives, all workers engaged in traffic management
activities and incident support services, and any other activities where live traffic is
present, (such as persons carrying out survey and inspection work).
‘Workers’
Population 3 – Other parties, including road users, the police and emergency services and
non-motorised ‘Users’ such as equestrians, cyclists and pedestrians, as well as those others
not in a contractural relationship with the Agency, such as privately contracted vehicle
recovery and vehicle repair providers.
‘Users’
Population 4 – Third parties includes any person or persons who could be affected by the
SRN, but who are neither using it, nor working on it, i.e. living or working adjacent to the
SRN, using other (non-Agency) transport networks that intersect with the SRN (e.g. local
roads, railways) and those who are living or working in properties owned by the Agency.
‘Other
Parties’
Table 1 – Defining and Brigading Populations
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Chapter 3
Duties and Responsibilities
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3. Duties and Responsibilities
3.1 The safety of ‘Workers’ (see Table 1), is governed
by employer responsibilities under Health and Safety
legislation. When considering safety risks to these
populations (both planned and incident management),
the duties of an employer are discharged through
compliance with the Management of Health and
Safety at Work Regulations 1999. (Regulation 3 deals
with risk assessments). Where the Agency acts as a
designer (either directly or through its supply chain),
the requirements to address safety risk assessment
for all populations exposed (during construction and
maintenance works) is covered by the Construction
(Design and Management) Regulations 2007
(particularly Regulation 11).
3.2 The Construction (Design and Management)
Regulations 2007 (SI 2007/320), (the CDM
Regulations) define ‘structure’ as including a road.
The CDM Regulations define ‘workplace’ as a
workplace within the meaning of regulation 2(1)
of the Workplace (Health, Safety and Welfare)
Regulations 1992 (SI 1992/3004 as amended) (the
1992 Regulations), other than a construction site. In
regulation 2(1) of the 1992 Regulations ‘workplace’
is defined as ‘any premises or part of premises which
are not domestic premises…made available…as a
place of work…other than a public road’. Thus a
designer must consider the use of a public road in
the context of its use by ‘Users’ (Population 3 from
Table 1) for normal operation only.
3.4 The principal difference between the populations
defined and then brigaded in Table 1 is the level of
control that the Agency has over each, e.g. ‘Users’
have a responsibility for their own safety and are
responsible for their actions that may affect the safety
of others. Whereas ‘Workers’ are acting on behalf of
and representing the Agency and thus their safety risk
exposure is controlled by the Agency’s management
and operational control processes.
3.5 The activities of ‘Users’ and/or ‘Other Parties’
cannot be controlled in the same way as for ‘Workers’.
Instead it is expected that ‘Users’ will comply with
the law and the Highway Code and that they will take
account of all the prevailing conditions (including but
not limited to) the weather, road character and condition,
traffic level and composition, and any warning signs.
The scope of this control is shown in the diagram at
Figure 1.
3.3 The safety of ‘Users’ and ‘Other Parties’
(Populations 3 and 4 from Table 1) is generally
regulated under statute. There is only one exception
to this principle and that is when the use of the
road is temporarily constrained by the Agency
implementing roadworks. In this instance only,
the road is not in a state of normal operation and
the Agency’s responsibility under health and safety
legislation changes because it is ‘undertaking’
something. In practice this means that during
construction and maintenance works the Agency
has interfered with the normal operation of the
road and this attracts a greater liability, which
means that during the period of road work activity
the Agency must manage the safety risk exposure
of ‘Users’ differently.
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Workers
Users
Other Parties
Figure 1 – Scope of control
3.6
‘Users’ on the SRN can be reasonably expected to:
•
balance the safety risks of using the road network
against the social and economic benefits of
travelling;
•
have a general awareness of the safety risks
that they are exposed to (through training,
driving instruction and driving tests, road safety
campaigns, media reporting of collisions, warning
signs on the roads of specific hazards etc.);
•
have control over the safety risks to which they
are exposed, of which they are reasonably aware,
e.g. heavy rain, congested route; and
•
have a knowledge of their legal obligations whilst
using the road and are aware that there is an
expectancy that they comply with them.
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Chapter 4
General Principles
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4. General Principles
4.1 The approach set out in this Standard allows
safety risk tolerance, balancing judgments, and benefits
versus costs to be examined, while taking account of
available budgets and other duties when considering
safety measures. This is consistent with HSE guidance
for ‘sensible safety risk management’, which seeks
to ensure that ‘Workers’ and the public are properly
protected, and understand their responsibilities, while
providing an overall balance of benefit and safety risk.
4.2 Balancing benefits and safety risks, when
considering safety risk control measures, is
applicable for all aspects of highway design
maintenance and operation to and on a highway.
The starting point for development of a design
should be to consider the applicability of standards
(compliance with standards is one of the simplest
practicability tests), any additional controls must
be tested using the reasonably required approach.
However, where a substandard road feature exists
that does not contribute to the safety problem that
is the subject of the issue being investigated or
addressed; this feature should not automatically
be upgraded. When standards can not be fully
complied with or where safety risk exposure
is a concern, controls will need to be tested for
practicability.
4.3 All suitable potential measures to reduce
safety hazards encountered by ‘Users’ must be
assessed and those measures that are reasonably
required must be implemented. This means that
where the cost of a measure identified in the
assessment is, in the reasonable opinion of those
carrying out the assessment, disproportionate to
the benefit derived, then reasonable discretion may
be exercised not to implement that measure, but
this decision and the evidence used to inform it
must be documented. The following rules apply:
•
if the benefit cost ratio (BCR) of the measure
being considered is > 2 then it should be
considered;
•
if the BCR is < 1 then the presumption is
that this is disproportionate and should not
be promoted on safety grounds;
•
any other measures with BCR’s between
1 and 2 should be considered alongside all
the other options and where a greater benefit
could reasonably be achieved by allocation
of the cost of that measure elsewhere within
the scheme or a wider programme of works
this should be considered. Benefits will
generally be measured against a risk of
death, i.e. Value of Preventing a fatality
(VPF); depending on the data available other
measures such as Fatalities and Weighted
Injuries (FWIs), Personal Injury Accidents
(PIAs) or incidents could also be used.
4.4 Certain defined people in the ‘Users’ group
(Population 3, Table 1) will undertake a function
of their work on the SRN. However, this function
is governed by the statutory requirements on their
employer’s management and operational control
processes.1 Designers must undertake appropriate
liaison with stakeholders.
4.5 There is no single methodology for assessing
what is disproportionate in terms of safety risk
tolerance levels; decisions about safety risk and
the controls that achieve compliance have to
be carefully considered and specialist technical
knowledge and informed judgement is required.
4.6 The Agency can exercise discretion in
deciding to provide or omit certain safety control
measures. The factor that would be relevant
during any form of legal challenge is that A) a
decision must be taken and B) the decision must
be recorded. This means that a determination to
do nothing is a valid decision, if to do nothing is
the proper conclusion of the assessment process
outlined in this Standard and is documented.
However, it is unacceptable for safety risk
decisions to be made by default or for a decision
not to be recorded.
1 The definition of Road ‘Workers’ used in the Aiming for Zero vision and strategy document does not apply.
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4.7 Other terminology such as Globally at Least
Equivalent (GALE) describes a concept that is
sometimes used for highway projects. The Agency
will instruct when this principle applies and this will
generally be where schemes are not primarily safety
related. This situation may arise where the overall
scheme is being promoted on the basis of reducing
congestion. In this type of scenario the safety risk for
‘Users’ from some composite hazards may be allowed
to increase as long as the overall scheme delivers an
improved or as an absolute minimum the same global
level of safety risk for ‘Users’.
4.8 A tool to help decision makers has been provided
at Annex C, the tool is not a recipe for assessment and
is no replacement for sound judgment and technical
expertise.
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Chapter 5
Principles of Safety Risk Assessment and Control
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Part 2
5. Principles of safety risk assessment
and control
5.1 The safety risk management flowchart process
(Figure 2), applies to all situations described at
paragraph 1.7. However, its use depends on the context.
Examples of applying this process to different decision
types are provided in Chapter 6.
Stage 1 – Determine the scope
Stage 2 – Identify the hazards
Stage 3 – Identify relevant criteria for populations
Stage 4 – Consider existing risk exposure for each population
Stage 5 – Risk analysis, assessment and evaluation
Stage 6 – Risk control decisions
Stage 7– Document safety risk decision in a safety risk report
Stage 8 – Handover of safety risk report to operators
Stage 9 – Update and refresh the safety risk report when change proposed
Stage 10 – Monitor and review safety risk report assumptions
Figure 2 – Safety Risk Management Process
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Chapter 5
Principles of Safety Risk Assessment and Control
5.2 All of the actions described in this chapter
and in the technical requirement Chapter 6 must be
executed by competent persons. The competence
and approval process is described in Chapter 7.
Stage 1 – Determine the Scope
5.3 Describe what is included and what if
anything is to be excluded from the assessment and
record this. The scope may be a geographical area
in the case of a road scheme or the boundaries of a
decision, e.g. change of process for temporary traffic
management at roadworks. In either case the breadth
of the assessment or the subject of the decision must
be clearly articulated and documented.
Stage 2 – Identify the Hazards
5.4 Hazard identification must identify all
reasonably foreseeable hazards to all populations
collectively and individually, and for all modes
of operation, using methods appropriate to the
level of complexity of the issues. The aim is for
a comprehensive understanding of Who, What,
Where, When, Why and How populations are
affected. A systematic approach, using previous
experience where it exists, should be used as a
starting point. This may not always be possible,
such as when dealing with a new or novel activity
or situation, or when there is insufficient relevant
and reliable data available. In these instances
techniques, such as brainstorming may be required.
Other methods, e.g. hazard and operability studies
and Failure Mode and Effects Analysis, may also
be necessary in specific and technically complex
circumstances.
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•
the safety risk on the population; and
•
the Agency’s safety risk tolerance for this
population (see Chapter 6).
Stage 4 – Consider Existing Risk Exposure for each
Population
5.6 In 2001, the HSE published the report, ‘Reducing
Risk, Protecting People’, known as R2P2 (to explain
their approach to their enforcement role in considering
risk tolerability). It explains the concept of ‘trade off’,
whereby an increase in the safety risk from one hazard
can be balanced by a commensurate decrease in the
safety risk of another hazard.
5.7 To illustrate the safety risk assessment
approach applied by the Agency the updated
R2P2 version of the HSE tolerability of risk (ToR)
‘triangle diagram’ (see Figure 4) has been adapted
to fit the requirements and statutory duties relating
to highways. The ToR diagram was developed
by the HSE on the assumption that people will
tolerate safety risks to them if they receive
some commensurate benefit in return for being
exposed to the risk and that the people responsible
for exposing them to the safety risks will take
appropriate measures to minimise their exposure.
Thus consideration must be given to those persons
exposed to, or potentially affected by, a safety risk,
see Figure 3.
Stage 3 – Identify Relevant Criteria for the
Populations
5.5 Here the aim is to set out the relevant
criteria for the populations affected by the hazards
identified in Stage 2. This criterion is then used
to examine the need for additional safety risk
controls. The criteria to be considered must,
as a minimum, include:
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Individual
The safety risk to a single
person is used to represent the
risk of all those running the risk,
and a specified outcome.
RISK
The risk measure is the probability
of a typical individual member of
one of the constituent populations,
e.g. Worker, User or Other Party
being killed or injured during
a year whilst undertaking
a particular activity.
Collective
This is the safety risk, to a group
of people or a population,
associated with a particular
scenario, control measure or
hazardous event.
Quantified as the average number of
fatalities, or fatalities and weighted
injuries, per year that would be
expected to occur.
Figure 3 – Individual and Collective Safety Risk Definitions
5.8 For all populations (‘Workers’, ‘Users’ and ‘Other
Parties’) there are three regions of safety risk that each
population could find itself in:
Broadly acceptable – do nothing, (no additional
risk controls or analysis required).
•
Unacceptable – do something or stop the activity.
•
Tolerable – test for any reasonably required
safety risk controls that are not already
implemented.
Increasing individual risks and
societal concern
•
5.9
These are expressed in Figure 4.
5.10 Moving from the bottom to the top of the
triangle in Figure 4 represents increasing ‘safety
risk’ for a particular hazardous activity (measured
by the individual safety risk and societal concerns
it engenders). The dark zone at the top represents
an unacceptable region. There are three regions in
the TOR framework that inform the Agency’s rules
for decision making.
Unacceptable Region
Risk cannot be justified
save in extraordinary
circumstances
Reasonably practicable
control measures must be
introduced for risk in this
region to drive residual
risk towards the broadly
acceptable region
Tolerable Region
Broadly Acceptable Region
Level of residual risk regarded
as insignificant – further effort
to reduce risk is not likely to
be required
Negligible Risk
Figure 4 – The HSE’s TOR Model or ‘Safety Risk Triangle’
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can demonstrate that there are no further safety risk
control and mitigation measures that are reasonably
required. Similarly for ‘Users’ the individual safety
risk of death of 1:1,000,000 per annum corresponds
to a very low level of safety risk and is used as a
guideline for the boundary between the broadly
acceptable and tolerable regions.
5.11 The Agency applies the HSE tolerability
recommendations to ‘Worker’ and ‘User’
populations to help us understand the safety risk
exposure and tolerance levels for each of them
as shown in Figure 5. The safety risk exposure
to the ‘Other Parties’ population is not defined
in this Standard and must be dealt with on a case
by case basis.
5.12 The HSE advises that an individual safety risk
of death of 1:1,000 per annum for ‘Workers’ who are at
work and 1:10,000 per annum for members of the public
(Populations 3 and 4) who have a safety risk imposed on
them ‘in the wider interest of society’, should be used
as a guideline for the boundary between the ‘tolerable
and the unacceptable regions. This means that for a
worker a tolerable safety risk level could be 1:2,500
and for ‘Users’ this could be 1:15,000. Safety risk
located in the tolerable region is judged to be tolerable
so long as the determining organisation (the Agency)
5.13 An activity/project/scheme that exposes
‘Workers’ to a risk of greater than 1:1,000 per
annum, (e.g. 1:850) is ‘unacceptable’. Similarly
an activity/project/scheme that exposes users
to a risk of 1:9,500 is ‘unacceptable’. In these
circumstances, either the activities being
considered must cease, or additional control
and mitigation measures must be implemented
to reduce the safety risk to below the boundary
between tolerable and unacceptable, and to drive
the risk level down as far as is reasonably required.
“Users”
“Workers”
Less than
1 in 1,000
Greater than
1 in 1,000,000
Increasing risk
Greater than
1 in 1,000
Less than
1 in 10,000
Unacceptable
Tolerable
Broadly
Acceptable
Greater than
1 in 10,000
Greater than
1 in 1,000,000
Figure 5 – Agency Applying Exposure and Tolerance Levels
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HSE risk
to “Users”
Unacceptable
*Urban A roads 1 in 100,000
*Motorways 1 in 320,000
Increasing risk
*Rural A roads 1 in 50,000
1 in 10,000
Tolerable
1 in 1,000,000
Broadly
Acceptable
Figure 6 – Annual Risk of Death to Individual ‘Users’ by GB Road Type
5.14 The annual risk to road users by road type
diagram at Figure 6 has been developed using the same
boundaries as those used by the HSE for fatality risk to
members of the public. The figures used to calculate this
risk exposure and the process is attached at Annex B.
It can be seen that in all cases the ‘User’ annual risk of
fatality is firmly in the ‘tolerable’ region and whilst the
annual risk of road user fatality is tolerable on all road
types considered here, motorways are the safest roads
and are some six times safer than rural ‘A’ roads.
mitigation systems that are deemed to be
a minimum for the duty of care to be met,
i.e. the acceptable safety risk exposure for
the population.
•
Good practice that is available for mitigating
the safety risk (existing standards and/or
operational procedures.
•
The cost benefit of different options for
safety risk mitigation, as long as they deliver
a safety risk level lower than the maximum
tolerable safety risk for the populations
concerned (as shown in Figure 5) and meet
the minimum performance requirements.
•
The overall effects of the actions taken.
5.15 The level of safety risk deemed tolerable for
a project must take into account a number
of criteria:
•
The maximum level of safety risk that is
deemed tolerable for the section of road
by the decision maker (see Chapter 6 for
details). This might consist of a percentage
of the overall network or regional safety
risk profile or an absolute criterion in terms
of ‘Users’ Killed and Seriously Injured
(KSI) and expert advice may be required.
Levels of performance for safety risk
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Chapter 5
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Stage 5 – Safety Risk Analysis, Assessment and
Evaluation
5.16 For safety risk analysis the detail must be
proportionate to the safety risks being considered.
The appropriate safety risk analysis methods
may be either qualitative, semi-quantitative or
quantitative. A range of safety risk measures are
also available for communicating the outputs of
any safety risk analysis, including measures of
individual and collective safety risk. For details
of generic safety risk analysis methods please see
Annex A. Outputs from safety risk analyses are
compared with tolerability criteria and associated
regions of safety risk (see paragraphs 5.8 – 5.14)
All potential delivery options for a project must
be considered and one recommended that is most
likely to result in successful delivery whilst also
providing an acceptable level of benefit (and value
for money etc.).
5.17 Populations with safety risks that fall into
a broadly acceptable area must be regarded as
acceptable and no further risk controls introduced.
This means that if a population’s collective risk
exposure is located in the broadly acceptable region
then further risk assessment is not necessary.
5.18 A Safety Risk Assessment Tool (see Annex C)
has been provided to assist decision makers in assessing
the broad justification in terms of safety risk alone. This
tool does not address the other impacts and benefits of
the proposal. Where the Risk Assessment Tool is used,
a copy of the risk matrix assessment, including the
potential hazards identified and the reasoning behind the
selection of severity, likelihood and Overall Risk Level
should be included within the Safety Risk Report, see
Stage 7 of this chapter.
Stage 6 – Risk Control Decisions
5.19 Risk control is the process of implementing
measures that take into account the implications
for either A) a single risk or B) a range of
different risks and then what is needed to control
them across the different populations. Final risk
controls must maximise the collective benefit and
demonstrate that controls go far enough to manage
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the safety risks for all populations. Risk control
normally involves expenditure and effort, and
it is likely that a variety of different risk control
options that require different levels of investment
and effort will be identified. It is common practice
to review the BCR of the different options and
select those with the highest BCR. ‘Trade off’
enables examination of the adverse consequences
of options and the comparison of their relative
effect; facilitating a balanced decision through a
‘trade off’ between reducing the target risk (the risk
that you are seeking to address) and the increase in
other safety risks.
5.20 The process used must take account of safety
risk implications for all affected populations. And
the method to assess individual safety risk controls
shall be:
•
Define the control option;
•
Work out the safety risk implications (benefits
and disbenefits) for all affected populations,
including consideration of how the control
may affect human behaviour, (ie is there
evidence to suggest that a population may
behave differently because they feel safer
or less safe);
•
Consider if the option goes far enough to
manage safety risk and if any disbenefits
are tolerable (see below); and
•
Revise the option as necessary and repeat
until the optimum solution for all populations
is found.
5.21 A hierarchy of control measures exists and
this is known by the acronym ERIC, which stands
for Eliminate, Reduce, Isolate and Control. When
considering control measures; the aim should be to
work down through the hierarchy; this means that the
ideal option will be to eliminate the safety risk you are
seeking to control, but this may be unachievable or
the costs disproportionate so the decision maker will
progress down through the hierarchy applying benefit
cost considerations at each level and to each safety risk
being addressed. A flowchart for this element of the
process is shown at Figure 72.
2 ‘Other Parties’ are out of scope of this decision-making flowchart.
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Understand current problem
(Risk Assessment)
Identify potential control options
(Hierarchy of controls)
Understand implications
of potential control options
for ‘Workers’
Understand implications
of potential control options
for ‘Users’
Understand implications
of potential control options
for ‘Other Parties’
Do control options go
far enough for this
population/are any
increases in risk
tolerable
Do control options go
far enough for this
population/are any
increases in risk
tolerable
Do control options
go far enough for
this population/
are any increases
in risk tolerable
Eliminate options,
revise as necessary
and repeat
Determine
preferred option
Figure 7 – Controls Decision-making Flowchart
5.22 Tests for whether control measures go far
enough or whether any disbenefits are tolerable
depend on the population and the associated
responsibilities of the Agency to manage the
safety risk exposure to those populations (Chapter
2, Table 1), and the tolerability criteria described
previously (at 5.11 – 5.14). When calculating costs
and benefits, technical evidence and judgments
must be used to define the expected life/duration
of the technical product, project or scheme. The
COBA (Cost Benefit Analysis) manual provides
guidance on calculating BCR’s and the safety risk
rules for BCR’s are provided at 4.3. The tool at
Annex D may also be helpful.
November 2012
5.23 The expected life/duration of the technical
product, project or scheme will vary according to
the situation, e.g. for a technology product the life
may be 10 years, or for a three week maintenance
scheme it would be the duration of the scheme.
For simple, low value control measures, this may
be qualitative and based on the reasoned judgment
of a competent professional. However, as the level
of complexity, safety risk or uncertainty increases
so must the level of quantification of costs and
benefits.
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Chapter 5
Principles of Safety Risk Assessment and Control
5.24 For ‘Users’, the definition of reasonableness
takes account of the following:
•
Costs, time or resources to introduce controls
in one area should not impact on the ability
to implement other safety measures that
deliver more collective benefit or that have
a higher BCR.
•
Controls should not have an unreasonable impact
on the performance of the network, as measured
against criteria other than safety, e.g. journey
times or air quality.
5.25 In addition, the costs associated with preventing
a fatality should not generally exceed the established
value of preventing a fatality figure described in
‘WebTAG unit 3.4.1’ (Accidents Sub ObjectiveTable 3: Average value of prevention of road accidents
by severity and element of cost).
5.26 For ‘Workers’ (Populations 1 and 2)
evidence must be presented to demonstrate that
the sacrifice (in terms of time, money or effort)
of doing more would be disproportionate to the
benefits gained from doing it.
5.27 For ‘Workers’ and ‘Users’ it can be
reasonable for the safety risks associated with
individual hazards to increase. However, the
residual safety risk level must remain tolerable and
the populations subject to the increase in safety
risk is gaining some proportionate level of overall
benefit from the project or decision as a whole.
5.28 Where individual safety risk controls result
in a safety benefit to one population, the outcome
for other populations must be that they are not
disproportionately adversely affected in safety
terms and the residual safety risk to a negatively
affected population must always at least remain
within tolerable parameters.
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5.30 There is no simple methodology for
computing what is reasonably required and
identifying a proportionate solution. Where there
is a need to balance safety risk across different
populations, the preferred safety risk control will
A maximise safety risk reduction to the population
with the highest current level of individual or
collective safety risk exposure and B offer the least
detriment to the trade off population and C will
represent the best overall balance of net present
value and benefit cost ratio.
5.31 An extreme trade off example might be to spend
£1m to prevent five staff suffering bruised knees is
likely to be grossly disproportionate; but to spend £1m
to prevent a bridge collapse capable of killing five
people is likely to be proportionate.
5.32 At this stage it is appropriate to think about the
sensible review period for the safety risk assessment
and control measures under consideration.
5.33 The decision about whether or not a control
measure is justified will often be based on economic
grounds. Thus if a control measure is being disregarded
then the impact to the population of any potential
increased safety risk stemming from this decision can
be estimated in cost terms. This then can be compared
with the cost of doing more and thus allow a more
informed decision to be reached. A Cost Benefit tool
has been provided at Annex D to help decision makers
assess whether control measures go far enough. The tool
uses an order-of-magnitude technique which provides a
simplified methodology to allow designers to consider,
on comparable terms, the control measure cost savings
against a judgement of the maximum likely change in
safety risks. This tool should only be used as a filter and
not a single deciding factor since non-accident related
impacts (e.g. delays) are not taken into account.
5.29 Safety risk controls are not fixed. It is appropriate
to remove safety risk controls that are no longer
reasonable/reasonably practicable in circumstances
where safety risk profiles, legislation, or approved
codes of practice have changed.
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Stage 7 – Document Safety Risk Decision in a Safety
Risk Report
5.34 Details of the safety risk assessment must
be recorded in a safety risk report, the detail of
which will be commensurate with the matter under
consideration and will include:
•
the hazards identified and evidence
considered;
•
details of the safety risk analysis and safety
risk assessment;
•
details of safety risk controls considered
and the rationale for why the final choice of
safety risk control was considered sufficient;
•
any time limits on the validity of the safety
risk assessment/any known or anticipated
changes that would require the safety risk
assessment to be reviewed;
•
who did the safety risk assessment (and
evidence that they were competent, see
Chapter 7 for competence requirements).
5.35 The scale of the safety risk report will be
guided by the complexity of the situation, it may
be a standalone report for a Type C decision and
equally for a Type A decision could be a composite
part or section of another project report.
Stage 8 – Handover of Safety Risk Report
to Operators
5.36 The safety risk report is a living document
that must be handed on to the next responsible
authority, be that a different part of the same
organisation or a separate organisation, where this
is appropriate, e.g. a built road scheme passing
from those responsible for construction to those
responsible for operation and management. Thus it
must be retained in a suitable format to make sure
that it is retrievable for the life of the safety risk
controls to which it relates.
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Chapter 5
Principles of Safety Risk Assessment and Control
Stage 9 – Update and Refresh the Safety Risk Report
when Change Proposed
5.37 Safety risk assessments contained within
a safety risk report are live documents which
must be reviewed and updated throughout the
life of the project and its subsequent migration
to maintenance and operation as part of the SRN:
•
whenever the activity they relate to
changes; or
•
when new information or findings from
any investigations or problems reported
by Workers/Others means that the outcome
may change;
•
to reflect any changes in legislation.
5.38 When risk assessments are updated
consideration should be given to industry best
practice, budgets and other duties, change in
situation and ensuring that controls remain
reasonably required.
Stage 10 – Monitor and Review Safety Risk Report
Assumptions
5.39 The assumptions that were used to:
•
inform the risk analysis and assessment;
•
inform the risk controls;
•
inform the decisions about whether risks
are tolerable;
must be updated periodically to ensure that
uncertainties are validated and performance
reviewed. The monitoring regime shall be
contained within the safety risk report.
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Chapter 6
Technical Requirements
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6. Technical Requirements
6.1 The previous chapters have articulated the general
requirements in terms of safety risk analysis, assessment
and evaluation, the content of this chapter explains:
•
Who should be the decision maker.
•
What decision makers should take into account,
as part of their decision making.
•
An approach that can be used to guide decision
making.
•
How much information decision makers should
document for an audit trail.
6.2 The minimum requirement is that the
outcome of safety risk analysis must be recorded
to demonstrate that decisions:
•
Meet Agency requirements.
•
Meet legal requirements.
•
Take account of all relevant factors.
•
Maximise the overall return from available
resources.
•
Take account of any implications for others
affected by the decision, in both the short
and long term.
•
Lead to reasonable, proportionate and
defensible set of actions.
•
Produce an appropriate audit trail.
6.3 There are three main inputs into decision making
as shown in Figure 8.
Appraisal of
cost and
benefits
Decision
Making
Understand
risks and
uncertainties
Understand
issues
Figure 8 – Decision-making Inputs
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6.4 There are four principal steps to making a
decision and these are:
•
defining the decision to be made;
•
establishing decision objectives and determining
decision boundary;
•
evaluating disproportion and tolerability; and
•
documenting the decision.
6.6 Decisions need to be made by the most
appropriate person and thus a method to identify
the decision boundaries must be applied; To do
this the decision must be characterised (i.e. wholly
Type A, B or C, or as containing a mix of Type
A, B or C characteristics). Table 2: provides an
approach that can be used to determine ‘features’
and thus characterise the decision; the feature
descriptions can be amended to suit the decision
under consideration.
6.5 The Agency uses a three-tiered approach (as
illustrated in Figure 9) to reflect the safety risks and
uncertainties associated with different decision levels
related to the complexity of issues. As the level of
complexity increases (e.g. the greater the number of
scheme elements and/or control measures are involved),
the greater the number of ‘trade off’/balancing decisions
that are required, so the higher the decision-making
referral goes.
Type C – These are decisions which are complex
infrequent and/or have major implications for the
SRN and, as such, require a detailed and rigorous
approach.
Type C Decisions
Professional Roles
Type B – These are decisions that could have
some significant operational implications.
Type A – These are relatively
routine decisions, are familiar,
and without operational
implications. The main issue
for these types of decision
is to ensure they are made
consistently with minimum
effort and maximum efficiency.
Figure 9 – Decision-making Pyramid
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Type B
Professional Safety
Advisors
Type C
Professional Roles
Local, low density
What is the size of the decision
impact? (geographically and in impact
terms; extent of the network, number
of ‘Users’/‘Workers’)
Local, high density or
national, low density
National, high density
What are the cost implications of the
decision for the Agency?
Medium
High
Months to a few years
Decades
Features
Type A
Specialist Technical/
Coordinator Roles
Low
Rest of the day
What is the lifetime of the decision?
(how long will the Agency be affected
by the decision)
What is the level of safety risk or
uncertainty associated with the
decision?
Low
Medium
High
What is the policy or stakeholder
interest level? (how sensitive is it?)
Low
Medium
High
Note: Stakeholder could be many bodies, e.g. user, worker, another road authority MP etc.
Table 2 – Characterising Decision Features
6.7 The decision maker should refer to any outputs
from previous safety risk analysis, assessment and
evaluation work in relation to the matter under
consideration, e.g. if a decision or a feature within it has
previously been characterised as a Type C this should
inform the current decision level ascribed. All evidence
considered (both retrospective and new) should be
referenced in the safety risk report.
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6.8 Having characterised the individual features of
the decision (using Table 2) the next step is to determine
a resultant overall type for each aspect of the decisionmaking process. The ‘characterisation rules’ in Table 3
should then be used to identify the appropriate decision
maker; this will usually be decided by the project in
consultation with the specialist technical advisor.
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Project Feature
Classifications
Decision Type
Comments
All Type A
Type A
Where all decision features are classified as Type A then the entire decision
will be of Type A.
All Type B
Type B
Where all decision features are classified as Type B then the entire decision
will be of Type B.
All Type C
Type C
Where all decision features are classified as Type C then the entire decision
will be of Type C.
Three or more
Type B,
remainder
Type A
Type B
Where three or more decision features are classified as Type B and the
remainder are Type A, then the entire decision shall be of Type B.
Three or more
Type C
Type C
Where three or more decision features are classified as Type C then the
entire decision shall be of Type C.
Equal
distribution of
classifications
across features
Type B/C
Where there is an equal distribution of classification features then the
decision shall be governed by the relative importance of the classifications,
i.e. a decision may still be a Type B with two Type C features. In this
instance then the overall decision type would be Type B but the two
features that were identified as Type C would require a greater rigour
of analysis assessment and evaluation.
Table 3 – Characterisation Rules
6.9 When the general approach has been decided
between either Type A, B or C, the decision maker
must then identify how individual options can be
compared to each other. This process is known as
establishing decision criteria. The basic process for
undertaking this task is summarised in Figure 10.
6.10 Within the Figure 10 flowchart, value does
not necessarily mean monetary, i.e. the results of
cost benefits analysis although this will often be the
case. Non-monetary types of decision criteria are:
6/4
•
Direct data – i.e. collision statistics, number
of vehicles.
•
Safety risk exposure of workers.
•
Safety risk exposure of users.
•
Reliability/effect upon congestion.
•
Financial.
6.11 Whatever criteria, employed, the same
combination must be used for all options under
consideration so that like for like comparison can
be made.
6.12 The preferred option for assessment is Quantitative
– either financially (i.e. value in terms of £) or nonfinancially (e.g. score out of 100, or absolute value
in units other than £). Where it is reasonable to do
so, effort should be made to assess decision criteria
financially, as this is the easiest way of making direct
comparison between the options. The last resort is
qualitative assessment, (e.g. high/medium/low or good/
average/poor) which should only be used where the
required effort to collect additional robust information
is disproportionate to the scale of the decision or it is
not practical to quantify the decision criteria (e.g. some
dynamic decision making).
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Establish individual
decision criteria
Determine the approach to
assessing criteria
Revise Option
Unacceptable
For each option assess a ‘value’ for each
of the criteria
For each option: Check criteria ‘values’
Acceptable
Assess individual options
Figure 10 – Basic Process for Establishing the Decision Criteria and Assessing Options
(see para 6.10 for explanation)
6.13 Type A decision criteria – These are
decisions which are relatively routine and familiar
so there should be plenty of existing professional
experience and direct data to inform Type A
decisions thus; additional analysis should not be
needed to inform these decisions.
6.14 Type B decision criteria – These are more
complicated decisions where the Agency is likely
to have some knowledge and experience, but it
is unlikely that there will be sufficient directly
relevant professional experience or data to form an
evidence base. Consequently more formal analysis
will be required.
6.15 Type C decision criteria – these decisions are
more complex and less common there is likely to
be very little if any directly relevant professional
experience or data. Therefore Type C decisions will
need to make significant use of analysis.
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6.16 The main purpose of establishing decision
criteria and valuing individual options against them
is to inform an overall assessment (or valuation)
of the individual decision options. This will then
form the basis for a comparison of options in order
to identify the optimum solution. This is where the
decision maker must consider trade-off, balancing
decisions and wider implications.
6.17 Further guidance on calculating the Net Present
Value (NPV) and BCR, including what costs and
benefits to include and appropriate discount rates, is
provided in the HM Treasury Appraisal and Evaluation
in Central Government, the ‘Green Book’.
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6.18 When the decision value boundary has been
established and the need to escalate or delegate
(see Figure 9 Decision-making Pyramid) has
been considered the next step is to take all of
the information gathered in the earlier stages of
this chapter and make a decision. Depending on
the complexity of the situation this may mean
that ‘trade off’ between exposures needs to be
considered, safety risk balanced, or disproportion
considered. The decision maker’s workflow for
‘trade off’ decisions is as shown in Figure 11.
6.19 It is only appropriate to consider trade off for
a road population with an intolerable risk exposure
if the trade off is to improve that risk exposure.
6.20 To assess tolerability reference should be made
to the most recent version of the ‘Information for
Managing Safety on the Highways Agency Network’
report. This report is updated annually and provides
an update at a national level of user safety risk; please
contact the team responsible for safety risk and
governance for advice, support and access.
6.21 Where there is more than one option then
the decision maker needs to make a ‘Balancing
Judgment’. The process of doing this is often
known as Multi Criteria Analysis (MCA). In
this situation the decision maker will follow
the workflow at Figure 11 and compile a list
of acceptable proposals and plot these onto a
performance matrix (e.g. Table 4). This presents
the decision criteria and associated values for
each option, as determined from the steps set out
previously in this chapter.
Review Safety
Risk Report
Review current safety
risk exposure of populate
Review current safety
risk exposure of populate
New risk exposure is tolerable.
All reasonably required controls
have been implemented
New risk exposure
is intolerable
Accept proposal and
document decision
Reject option and refer
for additional analysis
 
Figure 11 – ‘Trade off’ Workflow
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Decision Options
User Safety
Worker Safety Risk
Exposure
Cost
Option 1
2.5 PIAs saved/yr
1/1,500
£500k
Option 2
6 PIAs saved/yr
1/2,100
£1.5m
Option 3
4 PIAs saved/yr
1/1,050
£750k
Table 4 – Example of an MCA performance matrix
6.22 If the performance matrix does not clearly
indicate the best decision option it will be necessary
to either test for disproportion or convert the criteria
values (see para 6.10) to a consistent set of scores,
and then give relative weights to the criteria.
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Chapter 7
Roles, Responsibilities and Competence
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7. Roles, Responsibilities and Competence
7.1 In order to assign appropriate competencies
for each function/role involved in developing
an option and taking it forward for a decision
through the approval process, it is necessary
first to consider what is involved in each role.
This consideration is provided by developing
a Responsible, Accountable, Consulted and
Informed (RACI) matrix for the process. Table 6
(overleaf) provides an example of a RACI with
suggested assignments.
7.2 The RACI matrix process requires that all of the
steps in a process are mapped out and that each role
that undertakes an element of the process is identified.
Then appropriate RACI assignments are allocated to
fields in the matrix by combining these two factors.
The interpretation of each RACI assignment is given
in Table 5.
7.4 Accountability must not be delegated for any
activity. However, responsibility can be. In practice
this distinction means that an individual who is
accountable for completing a step in the decision
making/approval process can delegate the detailed
checking to another person, but in such a case they
must be sure that they are delegating the task to a
person with sufficient competence.
7.5 Those who use this standard who are
participants in the safety risk management
process will need to refer to both the RACI and
competency definition charts to be clear about
their responsibilities, decision-making levels and
competency requirements. Assessing competence
is covered later on in this chapter.
7.3 The RACI matrix illustrates the interaction
between different roles and responsibilities for the
various tasks that make up the safety risk management
process and details differences in decision making/
approval responsibilities. Competence levels of
achievement are shown in Table 7.
Assignment
Interpretation
Responsible
This person is responsible for action/implementation and typically the individual(s) who
actually complete the task. However, in some circumstances this person may delegate
parts of the work to others, including other organisations. Under these circumstances they
retain responsibility for ensuring that the task is completed. Responsibility can be shared,
with the degree of responsibility on each person determined by the ‘Accountable’ person.
Accountable
The individual or group who is ultimately answerable for the function/activity. Includes
‘yes’ or ‘no’ authority and veto power. Only one ‘A’ can be assigned to a function and this
accountability cannot be delegated to another role.
Consulted
The individual(s) to be consulted prior to a final decision/action. Communication
should be two way, there being a requirement on whoever is consulted to respond to the
information provided.
Informed
The individual(s) who needs to be informed after a decision/action is taken. The
communication is one way. There is no requirement for an informed person to respond.
Table 5 – RACI Assignments Interpretations
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Project
Consultant/
Designer
HA Project
Sponsor
HA Technical
Specialist
HA Regional
Manager
Professional
Safety Advisor
Professional
Roles
Safety Risk
Management
Process
Task
Decision Type/RACI assignment
Options or
feasibility stage
Determine
the scope of
the safety risk
assessment
Define Project
Scope
All types – R
All types – A
All types – C
All types – C
Define safety
baseline
objectives
All types – R
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Characterise
Project Features
All types – R
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Identify the
hazards
Hazard
identification
All types – R
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Identify and
consider
organisational
safety risk
tolerance
Confirm project
justification
All types – R
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Identify the
All types – R
Agency’s safety
risk tolerance for
each population
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Understand
safety risks
associated with
option
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Agree Preferred
Option
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High level safety
risk analysis
and safety risk
assessment
All types – R
Table 6 – Example of a Safety Risk Management RACI Matrix
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Project
Lifecycle Stage
Chapter 7
Roles, Responsibilities and Competence
7/2
Responsibility and Decision-making Levels
for Tasks
Project
Lifecycle Stage
Development
Stage
Safety Risk
Management
Process
Detailed safety
risk analysis and
detailed safety
risk assessment
Task
Project
Consultant/
Designer
HA Project
Sponsor
HA Technical
Specialist
HA Regional
Manager
Professional
Safety Advisor
Professional
Roles
Decision Type/RACI assignment
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Identify the
overall safety
risk benefit/
disbenefit
between options
considered
All types – R
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Understand
safety risks
associated with
option for all
populations
during all
phases of
implementation
All types – R
All types – A
All types – C
Type B – C
Type C – C
Type B – C
Type C – C
Type C – C
Establish current All types – R
level of safety
risk for each
population
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Identify the
All types – R
Agency’s safety
risk tolerance for
each population
All types – A
All types – C
Type B and C
–C
Type B and C
–C
Type C – C
Table 6 – Example of a Safety Risk Management RACI Matrix (continued
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Chapter 7
Roles, Responsibilities and Competence
Establish current All types – R
level of safety
risk for each
population
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Responsibility and Decision-making Levels
for Tasks
Project
Lifecycle Stage
Safety Risk
Management
Process
Safety risk
Control
Task
Project
Consultant/
Designer
HA Project
Sponsor
HA Technical
Specialist
HA Regional
Manager
Professional
Safety Advisor
Professional
Roles
Decision Type/RACI assignment
Type A and B
–R
Type A – A Type Type A – C
B – C/A
Type B – C
Type B – C
Type B – C/A
Type C – C/A
Identify potential All types – R
safety risk
control options
Type A – A
All types – C
Type B and C
–A
Type B and C
–C
Type C – C
All types – R
Type A – A
All types – C
Type B and C
–A
Type B and C
–C
Type C – C
Decide
whether safety
risk control
options for
each individual
population go
far enough are
any increases
in safety risk
tolerable
All types – I
Type A – A
Type B – C/A
Type C – C
All types – I
Type A – I
Type B – A/C
Type C – C
Type B – I
Type C – A/C
Consider tradeoff/balancing of
safety risk
All types – I
Type A – A
Type B – C/A
Type C – C
All types – I
Type A – I
Type B – A/C
Type C – C
Type B – I
Type C – A/C
All types – A
All types – I
All types – I
Type B and C – I Type C – I
Understand
implications for
each individual
population
November 2012
Develop project
safety plan
All types – R
Table 6 – Example of a Safety Risk Management RACI Matrix (continued)
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Determine if
project justified
on basis of
current level of
safety risk
Chapter 7
Roles, Responsibilities and Competence
7/4
Responsibility and Decision-making Levels
for Tasks
HA Project
Sponsor
HA Technical
Specialist
HA Regional
Manager
Professional
Safety Advisor
Professional
Roles
Project
Lifecycle Stage
Safety Risk
Management
Process
Construction or
implementation
stage
Document safety Ensure delivery All types – R
risk decision in a is as per the plan
safety risk report and all safety
risk controls
implemented
All types – R
Type C – C
All types – A
Type C – C
Type C – C
All types – R
Document
changes in
project safety
plan and develop
further as
necessary
All types – R
Type C – C
All types – A
Type C – C
Type C – C
Operation
Task
Project
Consultant/
Designer
Decision Type/RACI assignment
All types – R
All types – R
Type C – C
All types – A
Type C – C
Type C – C
Update and
Review
fefresh the safety performance
risk report when
change proposed.
All types – R
All types – R
Type C – C
All types – A
Type C – C
Type C – C
All types – R
All types – R
Type C – C
All types – R
Type C – C
Type C – C
Keep safety
documentation
up to date
Table 6 – Example of a Safety Risk Management RACI Matrix (continued)
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Chapter 7
Roles, Responsibilities and Competence
Handover of
Validate
safety risk report assumptions
to operators
and clarify any
uncertainties
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Responsibility and Decision-making Levels
for Tasks
Chapter 7
Roles, Responsibilities and Competence
7.6 The essence of competence is relevance to the
workplace. What matters is that there is a proper focus
on both the safety risks that occur most often and those
with serious consequences. Competence is demonstrated
by the ability of the individual to undertake the functions
described in Chapters 5 and 6 of this Standard.
7.7 To be competent, an individual must be able
to demonstrate:
•
sufficient knowledge of the specific tasks to
be undertaken and the safety risks associated
with these;
•
sufficient experience and ability; and
•
they can recognise their limitations and
how these should be overcome (skills
development plans).
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7.8 The development of competence is an
ongoing process. Individuals should develop their
competence through experience in the job and
through training.
7.9 To evaluate the competence of individuals
an assessment will be required, assessments should
focus on the individual and their role in particular
functions to deliver projects. The assessment
should be proportionate to the safety risks,
size and complexity of the work. It is therefore
recommended that the levels of competence
achievement as described in Table 7 is used.
These levels are relevant to all staff regardless of
grade and can be used to identify strengths and
weaknesses in current performance and define
learning and development goals and progression
paths.
7.10 The functions that individuals are engaged
in should then be measured against Table 7 levels
of competence, an assessment checklist is provided
at Table 8.
Level
Description
Can lead/direct
1
Direct and plan the work of others and teams
Can guide and show
2
Lead peer review, check and verify the work of others
Can do independently
3
Undertake the function independently (though may receive contributions
from others)
Can contribute
4
Contributes to the work of others but doesn’t undertake the function
independently
Table 7 – Competence Levels of Achievement
7/6
November 2012
Description
Levels of competence achievement
Hazard, safety risk, hazard identification, safety risk analysis,
safety risk assessment (or evaluation), safety risk control,
safety risk management, safety risk versus uncertainty
Legal context
HSWA, MHSW Regs, CDM, Road Traffic Act, Highways
Act, Duty of care, corporate manslaughter, role of the HSE,
reasonably required
Safety risk management
principles
ALARP, GALE, precautionary principle, safety decision
making, importance of evidence/audit trails, safety
management systems (HSG65)
Determine the scope of
projects
Consideration, definition and documentation of the project
scope. The project/decision boundaries, impact on all
populations, local objectives, and local problems
Identify hazards arising from
scope of project and identify
safety risks to populations
associated with hazards
Checklists, brainstorming, qualitative, semi-quantitative,
quantitative, risk matrices
Define appropriate criteria
and tolerance for populations
Tolerability of safety risk, safety risk trade off (including
individual and collective)
Gather analyse, assess and
evaluate relevant data
HA methodologies, event trees, fault trees, bow-tie, causeconsequence, risk modelling, measures of safety risk, data
for safety risk analysis (and what to do if no data)
Analyse safety risk control
options and decide preferred
options
Hierarchy of safety risk control, approaches to determining
‘reasonableness’ and procedures for actively managing
safety risks
Decision-making
HSMS; safety policy; organisation; operational procedures;
safety risk assessment methodologies; tolerability criteria;
assurance; procedures for review of current approach;
potential issues with the current approach
2
3
4
Can lead/
direct
Can guide
and show
Can do
independently
Can
contribute
7/7
Table 8 – Assessment Checklist
Chapter 7
Roles, Responsibilities and Competence
Safety risk terminology
1
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Competence areas/functions
Chapter 8
Glossary
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8. Glossary
Term
Explanation
Agency
The Highways Agency.
Assumptions
Assumptions are required in order to assess the degree of severity
and likelihood of the hazard.
Construction and maintenance
worker
Person whose job it is to perform construction and maintenance tasks
on projects, from within a safe working area.
CDM Regulations
The Construction (Design and Management) Regulations.
Decision Maker
The individual or group of individuals appointed with a mandate to consider
and determine safety risks at a defined level in accordance with this standard,
and identified on the project specific RACI charts. Decision Makers may be
in the Overseeing Organisation supply chain or the Overseeing Organisation
depending on the safety risks being considered and the requirements of the
project specific RACI chart. Decision Makers in the Overseeing Organisation
supply chain will also ensure that all the information pertinent to resolution of
the safety issue to be considered by the Overseeing Organisation is available
for that decision to be made.
Designer
A person, group of persons or organisation performing the duties of a designer
as defined by the CDM Regulations 2007.
Design Standards
The standards and specifications containing Mandatory Requirements
and used by the highway authority and stipulated as such in a standards
management system, other policy documents, contracts (e.g. ‘Employers
Requirements’) or a design brief or design statement.
Departure or Departure from
Standard(s)
A non-compliance with a Mandatory Requirement of a Declared Standard.
Design Manual for Roads and
Bridges (DMRB)
The Stationery Office publication containing current standards, advice notes
and other guidance documents relating to the design, maintenance, operation
and improvement of motorways and trunk roads.
GALE
Globally At Least Equivalent – a method of safety risk management
appropriate where safety improvements to ‘Users’ are not sought.
Hazard
A source of potential harm which poses a threat to ‘Users’, ‘Workers’,
or third parties.
Highway Authority
An organisation that is responsible for the maintenance of public roads.
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Chapter 8
Glossary
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Term
Explanation
Measures of impact
Needs to reflect the purpose of the safety risk assessment. Typical measures
of impact used by the Agency include:
•
Number of collisions.
•
Number of casualties.
•
Number of fatalities.
•
Numbers of killed or seriously injured (KSIs).
•
Fatalities and weighted injuries (FWI).
Mitigation measure
The aim of mitigation is to reduce or alleviate the hazard safety risk through
the use of qualitative or quantitative actions. After the initial hazard analysis
the drafter of the technical requirements should be able to identify possible
mitigations.
National Vehicle Recovery
Service Operatives
Persons employed as part of the HA National Vehicle Recovery Service.
Professional Safety Advisor
Group
A group comprising Safety Risk and Health and Safety specialists that
provide advice to Chief Highway Engineer.
Project
Anything that involves work or an activity on or affecting the SRN,
including surveys and inspections and construction, maintenance, upgrading,
improvement and renewal projects.
Project Feature
A high level property of the project that can be expected to affect safety
management requirements.
Project Manager
Person representing the Agency’s interests on the project and to whom
the Project Consultant reports.
Project Sponsor
Any person working for the Agency, representing the Agency’s interests
on the project.
Project Safety Risk
Management
The process of managing safety risks associated with project(s).
Safety Risk
The combination of the likelihood and the consequence of a specified hazard
being realised. It is a measure of harm or loss associated with an activity.
Safety Risk Analysis
A procedure to identify threats and vulnerabilities, analyse them to ascertain
the exposures, and highlight how the impact can be eliminated or reduced.
Safety Risk Assessment
The overall process of safety risk identification, safety risk analysis and safety
risk evaluation.
Safety Risk Evaluation
A process that takes the output of safety risk analysis and compares each
safety risk level against the safety risk tolerance and prioritises safety risk
controls.
Safety Risk Management
The overall process of safety risk assessment, plus processes for assigning
ownership of safety risks, taking actions to control them and then monitoring
and reviewing progress.
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Chapter 8
Glossary
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Term
Explanation
Safety Risk Measures
The outputs from safety risk analysis should be expressed in terms
of appropriate safety risk measures. These may include measures of:
•
individual safety risk;
•
collective safety risk.
The decision to present results in terms of individual or collective safety risk
will be based on the intended use of the information.
Safety Objective
A statement describing what if any contribution a project will deliver from
a safety perspective, generally associated with managed motorway projects
where the project is promoted on congestion reduction grounds.
Safety Risk Tolerance
The threshold levels of safety risk exposure that, with appropriate approvals,
can be exceeded, but which when exceeded will trigger some form of
response (e.g. reporting the situation to senior management for action).
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Chapter 9
Normative and Informative References
9. Normative and Informative References
Normative – separate documents referenced within the standard (unless otherwise stated, the most recent versions
of the separate documents should be referenced.
Title
Location of Document
Health and Safety At Work Act 1974
HSE Books
Design Manual for Roads and Bridges
The Stationary Office
Management Arrangements for Health and Safety
The Highways Agency
Agency Work Instructions and/or Guidance
Information for Managing Safety on the Highways Agency Network
WebTAG unit 3.4.1 (Accidents Sub Objective-Table 3: Average value
of prevention of road accidents by severity and element of cost
Department for Transport
Transport Statistics Great Britain
Informative – provides only additional background information.
Title
Location of Document
Reducing Risks Protecting People
HSE Books
Construction Design and Management Regulations 2007
Road Traffic Act 1988
The Stationary Office
Highways Act 1980
Green Book
Health and Safety At Work Act 1974
HSE Books
Managing the accidental obstruction of the railway by road vehicles
Department for Transport
COBA (Cost Benefit Analysis) manual
Aiming for Zero
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The Highways Agency
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Chapter 10
Abbreviations and Acronyms
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10.abbreviations and Acronyms
AfZ
Aiming For Zero
ALARP
As Low As Reasonably Practicable
BCR
Benefit Cost Ratio
BVM
Billion Vehicle Miles
COBA
Cost Benefit Analysis
DfT
Department for Transport
DMRB
Design Manual for Roads and Bridges
ERIC
Eliminate Reduce Isolate Control
FWI
Fatality and Weighted Injury
GALE
Globally at Least Equivalent
HSE
Health & Safety Executive
KMS
Kilometres
KSI
Killed or Seriously Injured
MCA
Multi criteria analysis
MAHS
Management Arrangements for Health and Safety
MM
Managed Motorway
NPV
Net Present Value
NSCRG
National Safety Control Review Group
PIA
Personal Injury Accident
PSCRG
Project Safety Control Review Group
PSA
Professional Safety Advisor
PSRM
Project Safety Risk Management
RACI
Responsible Accountable Consulted Informed
R2P2
Reducing Risk Protecting People
SFAIRP
So Far As Is Reasonably Practicable
SMS
Safety Management System
SRN
Strategic Road Network
TOR
Tolerability of Risk
TSGB
Transport Statistics Great Britain
VPF
Value of Preventing a Fatality
WI
Work Instructions
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Chapter 11
Enquiries
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11. enquiries
All technical enquiries or comments on this Standard should be sent in writing as appropriate to:
Chief Highway Engineer
The Highways Agency
123 Buckingham Palace Road
London
SW1W 9HA
G CLARKE
Chief Highway Engineer
This document was notified in draft to the European Commission in accordance with Directive 98/34/EC,
as amended by Directive 98/48/EC.
November 2012
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Annex A
Generic Safety Risk Analysis Methods
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Annex A Generic Safety risk Analysis
Methods
Qualitative
Quantitative
A1.1 Qualitative safety risk analysis methods generally
assess the likelihood and impact components of safety
risk using non-numerical, descriptive terms, e.g. high,
medium, and low. Results are often presented in a
likelihood-impact matrix.
A1.5 Quantitative safety risk analysis produces a single
point (absolute) value of safety risk, e.g. safety risk
of 2.3KSIs/yr. This is good for:
A1.2 This type of safety risk analysis is generally used
where there is a need for a quick prioritisation of a large
number of disparate safety risks. It is not generally
appropriate where:
•
there is a requirement for a detailed analysis of
whether or not targets have been met;
•
there is a need to take numerical data into
account;
•
there is a need to determine an overall (total)
level of safety risk from a particular activity
or project option;
•
there is a need to demonstrate the adequacy of
any safety risk controls or residual safety risk
levels using cost-benefit analysis.
•
detailed analysis of smaller numbers of
hazards, each of which has a range of possible
consequences;
•
taking data into account;
•
situations where there is a need to obtain a
reasonable estimate of the overall (total) safety
risk for an activity or hazard.
A1.6 This type of analysis is not generally appropriate
for analysis of large numbers of disparate safety risks.
Semi-quantitative
A1.3 Semi-quantitative safety risk analysis methods
tend to place likelihood and impact measures into bands
or numerical ranges, e.g. likelihood of ‘once every 5–10
years’; impact of ‘1–5 casualties’. As with qualitative
analysis, results are usually presented in a likelihoodimpact matrix.
A1.4 This type of safety risk analysis is generally
used where there is a need for absolute prioritisation
of a large number of disparate safety risks, using expert
judgments (or even data) expressed in numerical terms.
It can also be used to get an indication of overall (total)
safety risk from an activity or hazard. It is not generally
appropriate for detailed analysis of small numbers
of hazards, each of which has a range of possible
consequences.
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Annex B
Average Road User Safety Risk on GB Roads
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Annex B Average road user safety risk
on GB roads
B1.1 The calculations presented here can be used to
inform the section on risk tolerance criteria for road
users in this standard.
Basis of the Analysis
B1.2 Data used in this analysis was taken from
Transport Statistics Great Britain (TSGB), each year
new data is added and the calendar year relevant to these
calculations was 2011 (TSGB 2011) with the exception
of the numbers of fatalities by road type which have been
taken as the three-year average 2007-09 from the 2010
TSGB statistics because TSGB 2011 does not appear to
report fatality numbers by road type.
B1.3 A critical assumption in the following calculations
is that the results apply to road user safety risk on GB
roads. Whilst it may be possible to derive the equivalent
statistics for roads in England only, this has not been
undertaken at this stage.
Basic Data Used in the Analysis
B1.4 The tables show extracts from the TSGB data
that we have used for the analysis. Those numbers
with a letter after them (e.g. ‘(a)’) are referred to in
the equations that describe the calculations.
Year
Major roads (billion vehicle kilometres)
Motorway
2010
A’ roads
All major roads
Rural
Urban
All ‘A’ roads
139.8
79.7
219.5
98.2 (a)
317.7
Table B1 – Motor Vehicle Traffic by Road Class (TSGB 2011, Table TRA0202b)
Billion vehicle kilometres
Year
Cars and taxis
Motorcycles
Buses and
coaches
Light vans
Goods
vehicles
All motor
vehicles
2010
392.4
4.7
5.2
67.2
26.4
495.9
79% (b)
1%
1%
14%
5%
100%
% total
vehicle
kms
Table B2 – Road Traffic by Vehicle Type (TSGB 2011, Table TRA0201)
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Annex B
Average Road User Safety Risk on GB Roads
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Number of Registered Vehicles (TSGB 2011,
Table RDE0103)
B1.5 42.9 million (c)
Number of Full Car Driving Licence Holders
(TSGB 2011, Table NTS0201)
B1.6 35.3 million (d)
2007
2008
2009
3 yr average
Motorways
154
136
114
135 (e)
Urban A roads
469
420
374
421
Rural A roads
1,018
858
790
889
All A roads
1,487
1,278
1,164
1,310
Table B3 – Numbers of Fatalities by Road Class (TSGB 2010, Table 8.3)
Calculating Average Road User Safety Risk on GB
Motorways and ‘A’ Roads
B1.7 There are two sets of calculations to support this:
1.
Based on average vehicle kilometres per
registered vehicle on motorways and ‘A’ roads.
2.
Based on average kilometres per car driving
licence on motorways and ‘A’ roads.
Motorways
Rural ‘A’
Urban ‘A’
All ‘A’
2,291 (u)
3,261
1,859
5,120
Average fatalities per registered vehicle
3.1E-06 (v)
2.1E-05
9.8E-06
3.1E-05
Average risk of fatality of one in ……..
318,324 (w)
48,238
101,823
32,732
Average kilometres per registered vehicle
Table B4 – Analysis Per Registered Vehicle
Motorways
Rural ‘A’
Urban ‘A’
All ‘A’
2,202 (x)
3,135
1,787
4,922
Average fatalities per car driving licence
3.0E-06 (y)
2.0E-05
9.4E-06
2.9E-05
Average risk of fatality of one in ……..
331,183 (z)
50,187
105,937
34,054
Average kilometres per car driving licence
Table B5 – Analysis Per Car Driving Licence
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Annex B
Average Road User Safety Risk on GB Roads
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Deriving the Numbers
Tolerance Criteria
B1.8 The following equations show how the numbers
were derived for motorways. The numbers for ‘A’
roads are derived in a similar manner. Note that the
intermediate numbers presented here have been subject
to rounding for presentation purposes so may not
generate the same final results.
B1.11 The following schematic shows a possible
tolerance criteria framework for road users. There
is no statutory basis for road user safety risk upon
which we have drawn the criteria that determine the
boundaries between the three regions in the framework:
unacceptable; tolerable and broadly acceptable.
However, the numbers shown are the same as those
used in the Tolerability of Risk framework used by the
HSE for fatality risk to members of the public.
u = a / c = 98.2 × 109/42.9 × 106 = 2,291
v = e / c = 135/42.9 × 106 = 3.1×10­6
w = 1 / v = 1/3.1 × 10-6 = 318,324
x = (a × b) / d = (98.2 × 109 × 0.79) / 35.3 × 106 = 2,202
y = (e × b) / d = (135 × 0.79) / 35.3 × 106 = 3.0×10-6
z = 1 / y = 1/3.0 × 10-6 = 331,183
B1.9 It can be seen that there is very little difference
in the results when the analysis is based on either total
numbers of registered vehicles or total numbers of car
driving licences.
B1.12 Based on the simple analysis shown above and
using the proposed numbers we can map the average
annual road user risk of fatality onto it and it can be
seen that in all cases the road user annual risk of fatality
is firmly in the ‘tolerable’ region defined by the criteria
suggested. In this form it should be clear that whilst the
annual risk of road user fatality is tolerable on all road
types considered here, motorways are the safest roads
and are some six times safer than rural ‘A’ roads.
B1.10 For the purposes of establishing relatively
simple numbers that are consistent with the analysis
above we would propose the following average annual
risk of fatality to road users of:
Motorways
Urban ‘A’ roads
Rural ‘A’ roads
November 2012
1 in 320,000
1 in 100,000
1 in 50,000
B/3
Annual risk of death to individual road user
Annex B
Average Road User Safety Risk on GB Roads
Volume 0 Section 2
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Unacceptable
1 in 10,000
Rural ‘A’ roads, 1 in 50,000
Tolerable
Urban ‘A’ roads, 1 in 100,000
Motorways,
1 in 320,000
1 in 1,000,000
Broadly acceptable
Figure B1 – Annual Risk Death to Individual Road Users
Discussion
1.
The numbers used to generate this analysis are based on the TSGB and so do not represent the SRN exactly.
2.
The analysis is based on all road motor vehicles with a refinement for car vehicles only.
3.
The analysis is conservative in that it assumes that the population of road users is determined by the number
of registered vehicles or car vehicle licences. This is the same as assuming an average vehicle occupancy of
1.0 whereas we know that it varies between 1.2 and 1.5. If occupancy were taken into account this would
result in a decrease in the average vehicle kms per road user with an associated reduction in the annual
individual risk of fatality.
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Annex C
Hazard Identification and Risk Assessment Tool
Annex CHazard Identification and Risk
Assessment Tool
OVERVIEW
C1.1 Risk is the likelihood of potential harm from a
hazard being realised. The extent of risk will depend on:
•
The likelihood/probability of that harm occurring.
•
The potential severity of that harm, i.e. of any
resultant injury or adverse health effect.
•
The population which might be affected by
the hazard, i.e. the number of people who might
be exposed.
engineering judgement, consider all the factors that
affect probability in each individual case and select a
category. The reasoning behind the selection of category
should be recorded. The selection should be based on
additional accidents possible as a result of the decision,
not an expectation of ‘inherent’ underlying accidents for
the route or junction type.
Step 4: Assess the Risk Classification for each hazard
C1.6 Use the risk matrix below to assess the risk
associated with each hazard. Each hazard may result
in significant variations in risk between populations.
C1.2 There are various matrix methods of assessing
and recording risk. An example is given overleaf.
Step 5: Assess the overall Risk Classification for
the Decision
Step 1: Identification of hazards
C1.7 Where different populations are considered
separately, the element with the greatest Risk
Classification will generally define the overall Risk
Classification for the hazard.
C1.3 The first step of methodology involves the
identification of potential hazards.
Step 2: Assess the potential severity of harm
C1.4 For each hazard, make an assessment of the
potential severity in terms of accident type. The
reasoning behind the selection of severity category
should be recorded. The severity is normally related
to the most typical outcome rather than the worst case
outcome. Reported Road Casualties Great Britain gives
information at a national scale of severity outcomes, but
local data should also be referred to.
C1.8 Where there is more than one hazard, the hazard
with the greatest Risk Classification will generally
define the overall Risk Classification. However, the
person making the assessment needs to exercise
engineering judgement and a greater or lesser overall
Risk Classification may be selected provided that the
reasoning behind this decision is recorded.
Step 3: Assess the likelihood/probability
C1.5 For each hazard make an assessment of the
relative probability of an accident occurring, bearing
in mind that any accident is rare, random and multifactored. Probability is a function of exposure in
combination with other factors. Exposure can be
derived from vehicle flows and compositions. Other
factors that can affect likelihood include route type,
route function, route location. Using experience and
November 2012
C/1
Project/Decision
Date
Decision Maker/Assessor
Contact Details
Ref
1
2
3
Hazard Description
P
S
R
Response/Control Measure
P
S
R
Details
Risk classification and required action
Probability (P)
1
Minor
2
Moderate
Severity (S)
3
Serious
Risk Classification (R)
4
Major
1
2
3
Extremely unlikely
Unlikely
Likely
1
2
3
2
4
6
3
6
9
4
8
12
4
5
Extremely Likely
Almost Certain
4
5
8
10
12
15
16
20
Most common potential severity of harm e.g.
1 Minor harm
Minor damage or loss no injury
2
Moderate harm
November 2012
3
Likely
Once every 5–10 years
3
Serious harm
4
5
Extremely likely
Almost certain
Once every 1–4 years
Once a year
4
5
Major harm
Catastrophic harm
Slight injury or illness, moderate
damage or loss
Serious injury or illness, substantial
damage or loss
Fatal injury, major damage or loss
Multiple fatalities, catastrophic loss
or damage
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Probability that harm will occur
1 Extremely unlikely
Highly improbable, never known
to occur
2 Unlikely
Less than 1 per 10 years
5
Catastrophic Low (1–9) Ensure assumed control measures are
maintained and reviewed as necessary
5
10
Medium (10–19) – Additional control measures
needed to reduce risk rating to a level which is
15
equivalent to a test of ‘reasonably required’ for
the population concerned.
20
High (20–25) – Activity not permitted. Hazard to
be avoided or risk to be reduced to tolerable
25
Annex C
Hazard Identification and Risk Assessment Tool
C/2
Example Method of Hazard Identificationand Risk Assessment
Annex D
Cost Benefit Tool
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Part 3 GD 04/12
Annex d COST BENEFIT TOOL
Introduction
Step 3
D1.1 This tool is an order-of-magnitude technique
which provides a simplified methodology to allow
decision makers to consider, on comparable terms, the
whole life cost savings of non-inclusion of a control
measure against the decision maker’s judgement of
the maximum likely change in annual traffic accidents
arising from the non-inclusion.
D1.6 Obtain the total number of accidents equivalent
to the savings in whole life cost (N1)
Method
Step 4
D1.2 The methodology suggested here only applies
to localised changes to the infrastructure that are likely
to have no more than a minimal impact on other parts
of the network. This method of appraisal focuses
on comparing potential increases in the number of
accidents (the impacts) against whole life cost savings
from the infrastructure (the benefits). The analysis
concentrates on safety effects, without considering
vehicle, operating and time costs.
D1.8 Compare the annual number of accidents
equivalent to the savings in whole life cost (N2)
against the designer’s judgement of the maximum
increase in annual accident numbers likely to be caused
by the Decision from the design parameters required
by the Standard. Note: This can only be an order-ofmagnitude assessment not a detailed calculation.
D1.3 The methodology for the appraisal has the
following steps:
D1.9 It is stressed that this technique does not provide
an ‘answer’; it is simply an aid to designers in balancing
cost savings against possible increases in potential
accident risk. The technique will be particularly helpful
where the ‘accident equivalent’ of the whole life cost
saving is substantially larger (perhaps by several
orders of magnitude) than any possible risk that could
reasonably be expected to result from the decision, or
vice versa. But, even where this is the case, the designer
should ultimately judge whether the decision is likely
to be justified or not.
Step 1
D1.4 Obtain the savings in whole life costs (ΔC).
These are derived using the following expression:
ΔC = C2 – C1
where C2 represents the whole life cost of the control
measure(s), while C1 represents the whole life cost with
the control measure(s) incorporated.
Step 2
D1.5 Obtain the typical cost of an average accident
(A) for the relevant road type using the information
published in the latest version of ‘Reported Road
Casualties Great Britain’ which is published annually. It
can be found on the Department for Transport’s website.
This document gives the average cost of the prevention
of accidents for each injury category and different road
types. Select the appropriate figure for the particular
decision site.
November 2012
N1 = ΔC/A
D1.7 To obtain an equivalent annual accident figure
(N2), it is suggested that N1 is divided by the time
limits of the decision/scheme/project/life.
Site evaluation
Scheme evaluation
D1.10 Where the application of the above technique
shows that the decision may be associated with accident
disbenefit costs and these costs outweigh the potential
whole life cost savings, the decision maker should:
•
Consider the other non-safety benefits and their
relative importance.
•
Consider the scale of overall (macro level)
predicted scheme safety benefits for all design
elements and how these compare with the (micro
level) accident disbenefit costs at the geographic
location of the site and determine if the overall
safety benefits are justified, i.e. macro level
benefits minus the sum of individual micro levelrelated disbenefits.
D/1