Smart motorway supplements
Document number: 17.177 – April 2017
ISBN: 978-1-925582-84-0
Supersedes version: N/A
Austroads report AP-R341-09: Freeway design parameters for fully
managed operations
Section 9: Lane use management systems (LUMS) including
variable speed limits (VSL) (2009)
The Austroads report AP-R341-09 Freeway Design Parameters for Fully Managed Operations (2009)
provides guidance on design principles for motorway traffic management systems. Note that Austroads
use the term “freeway” and “managed freeway”, whereas Roads and Maritime use the term “motorway”
and “smart motorway”. Roads and Maritime has agreed to adopt Section 9 of the report as the primary
technical reference for use by Roads and Maritime for the Managed Motorway Lane Use Management
System (LUMS) including Variable Speed Limits (VSL).
This supplement is issued to clarify, add to, or modify Section 9 of the Austroads report where
appropriate.
Roads and Maritime accepts the principles in the Austroads report with variations documented in this
supplement under the following categories:
−
Roads and Maritime Enhanced Practice: Roads and Maritime traffic practices which enhance
the Austroads report.
−
Roads and Maritime Complementary Material: Roads and Maritime traffic reference material
that complements the Austroads report. These documents include Roads and Maritime Manuals,
Technical Directions and/or other reference material, and are to be read in conjunction with the
Austroads report.
−
Roads and Maritime Departures: Roads and Maritime traffic practices that depart from the
Austroads report.
Note: If there are any differences in practice between this Roads and Maritime supplement and other
Roads and Maritime complementary material, the Roads and Maritime supplement will apply.
For other related Roads and Maritime supplements, refer to the Supplement for Australian Standards
AS1742 Manual of Uniform Traffic Control Devices Parts 1 – 15, Supplement for Austroads Guide to
Traffic Management, Supplement for Austroads Guide to Road Design and Supplement for Austroads
Guide to Road Safety.
All road signage mentioned in this supplement should be checked against the Roads and Maritime
Roads sign register.
For enquiries and further issues to be added to this supplement email:
[email protected]
Document information
Title
Smart motorway supplement for Austroads report AP-R341-09: Freeway design
parameters for fully managed operations, Section 9: Lane use management systems
(LUMS) and variable speed limits (VSL) (2009)
Branch/Section/Unit
Road Network Operations
Author(s)
Katherine Boddington (ARRB), Maurice Burley (ARRB)
Contributors
Manager Network Performance Development – Fraser Johnson (Roads and
Maritime) and Michael Bajenov (Roads and Maritime)
Endorsed by
Manager Motorway Network Optimisation – Marco Morgante (Roads and Maritime)
Approved by
General Manager Network Optimisation – Martin Oaten (Roads and Maritime)
Date of approval
and effect
April 2017
Audience
Traffic Signal Designers, Motorway Traffic Engineers, Motorway Planners and
Designers.
Next review date
June 2018
Document number
17.177
ISBN
978-1-925582-84-0
Document history
Version
Date
Reason for amendment
Page No.
Editor
1.0
13/04/17
First published version
All
Fraser Johnson
/ Michael
Bajenov
Smart motorway supplements: Austroads report AP-R341-09: Section 9: Lane use management systems
April 2017 UNCONTROLLED WHEN PRINTED
2
Section 9: Lane use management systems including
variable speed limits (2009)
Reference
section
Roads and Maritime enhanced practice, complementary material, or
departures
Throughout
Section 9
Terminology and general comments
A Roads and Maritime departure is that where references in the report are to a
‘freeway’ these should be understood to be a reference to a ‘motorway’ and
where references in the report are to a ‘managed freeway’ these should be
understood to be a reference to ‘smart motorway’.
Additional
guidance to
Section 9
Description and legal significance
Roads and Maritime enhanced practice is that VSL/LCS are part of the lane use
management system (LUMS) to manage the speed limit and lane use on the
motorway.
Date
The VSL/LCS displays various symbols in an illuminated dot matrix
arrangement. VSL/LCS is used with all-lane running (no emergency stopping
lane) or across the running lanes of a motorway with a shoulder.
VSL/LCS displays are traffic control devices and have a regulatory function. The
VSL display must comply with Rule 21, part 3 and Rule 316, part 5 of Road
Rules-2008 and relevant sections of AS 1742, AS 1743 and AS 1744.
The VSL/LCS must satisfy the requirements of Rule 329 (Traffic control devices
applying to a marked lane) if it is above the marked lane and Rule 152
(Complying with overhead lane control devices).
An illuminated VSL/LCS display should consist of a main display area consisting
of red and white dots. The white dot matrix part of the display has a minimum
resolution of 32 x 32 pixels.
The white dot matrix part of the display must be able to display any symbols as
required for lane usage, such as up to three numerals for VSL, lane usage
arrows and crosses, Bus Lane, Transit Lane (T2, T3) or Truck Lane.
Smart motorway supplements: Austroads report AP-R341-09: Section 9: Lane use management systems
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Reference
section
Roads and Maritime enhanced practice, complementary material, or
departures
Additional
guidance to
Section 9
continued
VSL/LCS: Sign displays
Roads and Maritime enhanced practice for VSL/LCS displays are provided in
Table S1.
Description
Date
Display
Variable speed limit sign –
Typical values: 40, 60, 70, 80,
90, 100, 110
Merge left or merge right
Traffic in the lane to use the
exit ramp
Lane closed
Flashing Red Cross
Motorist must leave lane as
soon as safe to do so
alternating
with
Table S1: VSL/LCS displays
VSL/LCS: Sign size
Roads and Maritime enhanced practice is that the size of VSL/LCS is based on
the default speed limit for the motorway section:
−
Seed limit greater than 80kilometres per hour : ‘C’ size signs (900
millimetres wide)
−
Speed limit 80kilometres per hour or less: ‘B’ size signs (600 millimetres
wide).
Smart motorway supplements: Austroads report AP-R341-09: Section 9: Lane use management systems
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Reference
section
Roads and Maritime enhanced practice, complementary material, or
departures
Additional
guidance to
Section 9
continued
LCS: Signal displays
Date
Roads and Maritime enhanced practice for LCS displays are provided in Table
S2.
Table S2: LCS displays
Description
Display
Merge left
Merge right
Down arrow
or
Lane closed
Flashing Red Cross
Motorist must leave lane as
soon as safe to do so
alternating
with
LCS: Signal size
Roads and Maritime complementary material in relation to the size of LCS in
tunnels is provided in the Smart motorway design guide tunnel traffic
management (Roads and Maritime Services 2015).
Section 9.1
Overview
Section 9.1.1
Reversible lane systems
A Roads and Maritime departure applies to this entire section, which is not
applicable to Roads and Maritime practice.
Section 9.1.3
Non-integrated VSL and LCS (i.e. separate displays)
Roads and Maritime complementary material for provision of LCS and VSL in a
motorway tunnel environment is provided in the Smart motorway design guide
tunnel traffic management (Roads and Maritime Services 2015).
Section 9.3
Warrants
Roads and Maritime complementary material relating to warrants for LCS and
VSL is provided in the Smart motorway guidelines (Roads and Maritime Services
2015).
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Reference
section
Roads and Maritime enhanced practice, complementary material, or
departures
Section 9.3.1
VSL alone
Date
Roads and Maritime enhanced practice is that for VSL application alone (in the
absence of LCS) the side-mounted VSL signs are generally suitable for:
• On smart motorway entry ramps.
• On motorway-to-motorway ramps where there are ramp metering signals on
the ramp for the motorway being entered.
Roads and Maritime enhanced practice is that VSL must be integrated with LCS
when LCS is used on the mainline.
Section 9.4
Key freeway design principles
Section 9.4.1
Mounting structure
Roads and Maritime enhanced practice is that for VSL application alone (in the
absence of LCS) the side-mounted VSL signs are generally suitable for
carriageways up to 3-lanes wide (and which may include short sections with an
auxiliary fourth lane). On 3-lane carriageways with a high percentage of trucks,
overhead mounting using integrated LUS may be more appropriate to alleviate
visibility restrictions.
Section 9.4.3
Vertical clearance
Roads and Maritime complementary material for vertical clearances in a
motorway tunnel environment is provided in the Smart Motorway Design Guide
Tunnel Traffic Management (Roads and Maritime Services 2015).
Roads and Maritime complementary material relating to vertical clearances is
provided in the RTA Supplement to Austroads Guide to Road Design – Part 3
(2009) – Geometric Design (Roads and Maritime Services 2011) and Roadway
Tunnel Geometric Design - Commentary (Roads and Maritime Services 2006
draft).
Section 9.4.4
Horizontal clearance
Roads and Maritime enhanced practice is that the horizontal clearance for the
positioning of LUMS gantries should consider the impact of any future road
widening.
Section 9.4.7
Longitudinal position of VSL/LCS – Open road environment
A Roads and Maritime departure relates to the last sentence of the first
paragraph, which is not applicable for Roads and Maritime practice.
Roads and Maritime enhanced practice is that the maximum spacing of
VSL/LCS along the mainline for a single section should not exceed 800m and
also not exceed an average spacing of 600m.
A Roads and Maritime departure relates to Table 9.4, Figure 9.5 and Table 9.5,
which are not applicable to Roads and Maritime practice.
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Reference
section
Roads and Maritime enhanced practice, complementary material, or
departures
Section 9.4.7
continued
Roads and Maritime enhanced practice includes the following guidance on the
general design process for placement of VSL/LCS gantries and/or VSL signs:
Date
• Determine locations for direction signs as these are location specific
• Locate VSL/LCS gantries within the direction sign layout in the following
sequence:
o
Position gantries in the vicinity of interchanges. Roads and Maritime
practice for the location and spacing relative to entry ramps and exit
ramps at interchanges in shown in Figure S1
o
Position gantries in the sections between interchanges with a desirable
spacing of 500 metres to 600 metres (refer to the rationale in the note on
the next page). Where significant practical constraints prevent this
layout, nominal spacing up to the maximum of 800 metres may be used
for that location. However, this spacing should not be continued to
provide a series of widely spaced gantries, noting the maximum average
spacing requirement. The mounting of VSL/LCS on other infrastructure
may be considered in accordance with Section 9.4.2 of the report if
suitable locations exist within the spacing guidelines above.
• It is undesirable to position gantries at driver decision points, e.g. exit lane
taper, lane gain etc
• The placement of VSL/LCS gantries has priority over the location of variable
message signs (VMS).
Figure S1: Typical layout of VSL/LCS gantries at an interchange
Source: Managed Freeways Handbook for Lane Use Management, Variable
Speed Limits and Traveller Information (VicRoads 2013)
Smart motorway supplements: Austroads report AP-R341-09: Section 9: Lane use management systems
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Reference
section
Roads and Maritime enhanced practice, complementary material, or
departures
Section 9.4.7
continued
Note:
Date
The following principles have been considered in determining the longitudinal
spacing of LUMS gantries:
• Travel time between gantries. It is desirable for drivers to see a sign at least
every 30 seconds travel time (desirable range of short-term memory
retention) to retain lane status information. At various speed limit values the
travel distance in 30 sec. travel time is:
o
o
o
At 100 kilometres per hour: 833 metres (default speed limit)
At 80 kilometres per hour: 667 metres (default speed limit)
At 40 kilometres per hour: 333 metres (incident speed limit).
• Management of the distance over which transitions occur during incidents:
o
o
Speed limit reductions from the default speed limit to 40 kilometres per
hour may require multiple steps to suit the sequence of lane closure
steps
Lane closures with single, sequential lane reductions requires up to 4
steps for a 5-lane to 1-lane reduction.
• Degraded operation: If a VSL/LCS gantry is faulty or out of service, the
distance becomes significantly greater for lane and speed reductions.
• Roads and Maritime complementary material in relation to application of
speed limits on motorways is provided in the NSW Speed Zoning Guidelines
(Roads and Traffic Authority 2011).
Section 9.4.8
Longitudinal position of VSL/LCS – tunnel environment
Roads and Maritime complementary material in relation to placement of
VSL/LCS and LCS in tunnels is provided in the Smart Motorway Design Guide
Tunnel Traffic Management (Roads and Maritime Services 2015).
Section
9.4.10
Proximity to other signage
Section
9.4.12
Supporting static signage
Roads and Maritime enhanced practice is that if it is necessary to use colocation of signs in a design (VSL/LCS with direction signs, VSL/LCS with VMS
or VMS with direction signs) the positioning two types of dynamic signing
together, e.g. VSL/LCS with VMS, should be avoided.
Roads and Maritime enhanced practice provides the following additional
guidance relating to supporting static signage:
• Static speed limit signs indicating the default speed limit are installed
downstream of the section where VSL/LCS apply (mainline and exit ramps),
to indicate the speed limit beyond the controlled section.
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Reference
section
Section
9.4.12
continued
Roads and Maritime enhanced practice, complementary material, or
departures
Date
The following are required to indicate the appropriate speed limits if the
VSL/LCS displays no speed limit (eg system or power failure):
• Static speed limit signs indicating the default speed limit on the mainline are
installed upstream of the section where VSL/LCS apply, to indicate the speed
limit in the controlled section
• Static speed limit signs indicating the default speed limit are installed at the
relevant location within the section where VSL/LCS apply, if the default speed
limit changes
• Static speed limit signs indicating the default speed limit are successively
installed within the section where VSL/LCS apply (ie repeater signs).
Roads and Maritime complementary material in relation to application of static
signage for variable speed limits on motorways is provided in the NSW Speed
Zoning Guidelines (Roads and Traffic Authority 2011).
Additional
Roads and
Maritime
complement
ary material
to Section 9
NSW Speed Zoning Guidelines (RTA 2011, Sections 1.3, 1.6.3, 3.2.5 and
3.3.10)
• Note that within Sections 1.6.3 and 3.2.5 there is a reference to Variable
Speed Limits (VSL) Guidelines, however this document does not exist.
In Section 3.3.10 (a), a departure is the first bullet point which is not applicable to
Roads and Maritime practice and in relation to the last bullet, Roads and
Maritime enhanced practice is that G6-317 signs are also required where the
default speed limit changes within a managed motorway VSL scheme.
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