KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected]| WEB: www.kctt.com.au | KC01103.000 1 | Page Spencer Road (Hume Road to Regal Drive), City of Gosnells Median and turning pockets, Main Roads WA Option B Alignment Road Safety Audit Stage 2 - Preliminary Design Audit Ref: KC01103.000 Prepared for: City of Gosnells By: Colin Kleyweg Marina Kleyweg Report Issue Date: 1/12/2019 OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
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KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 1 | P a g e
Spencer Road (Hume Road to Regal
Drive), City of Gosnells
Median and turning pockets, Main Roads
WA Option B Alignment
Road Safety Audit
Stage 2 - Preliminary Design
Audit Ref: KC01103.000
Prepared for:
City of Gosnells
By:
Colin Kleyweg
Marina Kleyweg
Report Issue Date: 1/12/2019
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 2 | P a g e
Safety Audit Document Control Sheet
Project Location: Spencer Road (Hume Road to Regal Drive), City of
Gosnells
Project Proposal: Median and turning pockets, Main Roads WA Option B
Alignment
Audit Stage: Stage 2 - Preliminary Design
Prepared for: City of Gosnells
Prepared by 1: Colin Kleyweg
Prepared by 2: Marina Kleyweg
Audit Team Leader: Colin Kleyweg
Audit Team Leader
Organisation:
KCTT
Audit Reference: KC01103.000
Report Issue Date: 1/12/2019
The Safety Audit Document Control Sheet Above Should be Completed Prior to Editing Any Other
Part of the Report Template
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 3 | P a g e
1. INTRODUCTION
1.1 Scope of Audit
This Road Safety Audit has been undertaken in accordance with the requirements
contained in the Main Roads Western Australia Policy and Guidelines for Road
Safety Audit.
This report results from a Stage 2 - Preliminary Design Road Safety Audit carried out
on the proposed Median and turning pockets, Main Roads WA Option B Alignment
at Spencer Road (Hume Road to Regal Drive), City of Gosnells .
The background and objective of the proposed project is to install median and turning
pockets at Spencer Road from Hume Road to Regal Drive.
The Audit was undertaken by Colin Kleyweg and Marina Kleyweg of KCTT with
reference to the details provided in the Audit Brief.
The audit comprised an examination of the drawings and other information supplied
by the City of Gosnells as listed in Appendix C.
All the findings described in Section 2 of this report are considered by the audit team
to require action in order to improve the safety of the proposed project and to
minimise the risk of crash occurrence and reduce potential crash severity.
The audit team has examined and reported only on the road safety implications of the
project as presented and has not examined or verified the compliance of the design
to any other criteria.
1.2 The Audit Team
Auditor
No.
Name Role Organisation
326S Colin Kleyweg Audit Team Leader KCTT
514 Marina Kleyweg Audit Team Member KCTT
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 4 | P a g e
The audit team visited the site on 26.11.2019. at 17:00. At the time of the site visit the
weather was sunny and the existing road surface was dry.
A night-time site visit was undertaken on 26.11.2019. at 20:00.
1.3 Specialist Advisors
No other specialist advisors were present at the time of audit.
1.4 Safe System Findings
The aim of Safe System Findings is to focus the Road Safety Audit process on
considering safe speeds and by providing forgiving roads and roadsides. This is to be
delivered through the Road Safety Audit process by accepting that people will always
make mistakes and by considering the known limits to crash forces the human body
can tolerate. This is to be achieved by focusing the Road Safety Audit on particular
crash types that are known to result in higher severity outcomes at relatively lower
speed environments to reduce the risk of fatal and serious injury crashes.
The additional annotation “IMPORTANT” shall be used to provide emphasis to any
road safety audit finding that has the potential to result in fatal or serious injury or
findings that are likely to result in the following crash types above the related speed
environment: head-on (>70 km/h), right angle (>50 km/h), run off road impact object
(>40 km/h), and crashes involving vulnerable road users (>30 km/h), as these crash
types are known to result in higher severity outcomes at relatively lower speed
environments.
The exposure and likelihood of crash occurrence shall then be considered for all
findings deemed “IMPORTANT” and evaluated based on an auditors professional
judgement. Auditors should consider factors such as, traffic volumes and
movements, speed environment, crash history and the road environment, and apply
road safety engineering and crash investigation experience to determine the
likelihood of crash occurrence. The likelihood of crash occurrence shall be
considered either “VERY HIGH”, “HIGH”, “MODERATE” or “LOW” and this additional
annotation shall be displayed following the “IMPORTANT” annotation on applicable
findings.
1.5 Previous Safety Audits
A Stage 2 Preliminary Design was undertaken by KCTT in May 2018 under the
reference number KC00845.000.
The items raised in the Stage 2 Preliminary Design safety audit have been addressed
with the exception of the items listed below. These items are discussed again in this
road safety audit.
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 5 | P a g e
Earlier Audit Finding
Ref.
Description Audit Item Ref.
2.1
Length of left turn lane
deceleration lane –
Kenmare Avenue
2.1
2.6
No Left-turn splitter median
at intersection of Princeton
Court and Spencer Road
service road
2.3
2.7
No Left-turn splitter median
at intersection of Regency
Drive and Spencer Road
service road
2.4
2.9
Location of egress to
Spencer Road service road
too close to the left turn
deceleration lane entry to
Glyndebourne Avenue
2.7
2.10
Glyndebourne Avenue
Intersection angle to
Spencer Road (Left-Out)
2.8
2.13
No left turn splitter island at
intersection of Grenadier
Drive and Spencer Road
2.13
2.14
Lighting Conditions and
light pole locations on
northern side of Spencer
Road
2.14
1.6 Background Data
1.6.1 Crash History
A study of the recent crash history has been conducted in the vicinity of the proposed
project for the five-year period to the end of December 2018. This showed that there
were 44 reported crashes (11 midblock crashes and 33 intersection crashes) within the
extracted data for Spencer Street - Hume Road to Regal Drive (SLK 3.79 – 4.60) which
is summarised below:
Crash severity:
2 Hospital
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 6 | P a g e
2 Medical
24 PDO Major
16 PDO Minor
MR Type:
3 Involving Overtaking
1 Involving Pedestrian
1 Entering / Leaving Driveway
39 Unknown
Light Conditions:
35 Daylight
3 Dawn or Dusk
5 Dark - Street Lights On
1 Dark - Street Lights Not Provided
MR nature:
24 Rear End
3 Sideswipe Same Direction
11 Right Angle
1 Right Turn Thru
3 Hit Object
1 Non-Collision
1.6.2 Traffic and Speed Data
A summary of recent traffic data is provided below:
Location Vehicles per day
(% heavy vehicles) Date Source
Spencer Road –
South of Wilfred
Road
27,505
(3.4%) 2017/18 MRWA
Spencer Road –
north of Hume
Road
26,285
(N/A) Aug 2019
MRWA
(derived from
SCATS)
Spencer Road –
south of Hume
Road
25,306
(N/A) Aug 2019
MRWA
(derived from
SCATS)
Spencer Road
(East bound data)
11,601
(4.43%)
27/3/2014-
14/4/2014 City of Gosnells
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 7 | P a g e
– 50m West of
Denham Way, front
of house no. 404
Spencer Road
(West bound data)
– 50m West of
Denham Way, front
of house no. 397
11,905
(3.18%)
27/3/2014-
14/4/2014 City of Gosnells
A summary of recent speed data is provided below:
Location Average Speed
(km/h)
85th Percentile
Speed (km/h)
Date Source
Spencer Road
– South of
Wilfred Road
55.7km/h 61.8km/h 03/05/2018 MRWA
Spencer Road
(East bound
data) - 50m
West of
Denham Way,
front of house
no. 404
60.3 km/h 65.9 km/h 27/3/2014-
14/4/2014
City of
Gosnells
Spencer Road
(West bound
data) - 50m
West of
Denham Way,
front of house
no. 397
59.9 km/h 65.2 km/h 27/3/2014-
14/4/2014
City of
Gosnells
1.6.3 Appendices
Appendix A – Audit Findings Location Plan
Appendix B – Audit Photographs
Appendix C – List of Documents Provided for the Audit
Appendix D – Corrective Action Report (CAR)
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 8 | P a g e
2. ITEMS RAISED IN THIS STAGE 2 - PRELIMINARY DESIGN AUDIT
2.1 Finding – Length of Proposed Left-Turn Deceleration Lane to Kenmare Avenue
Length of left-turn deceleration lane does not conform to Austroads Guide to Road
Design for the speed environment in Spencer Road for vehicles to decelerate safely
within the deceleration lane. The reduced length of deceleration lane is due to the
presence of a bus stop, however with Spencer Road being a high frequency bus
route, particularly during peak hours this presents an additional conflict.
Justification of the finding:
There are two key risks with the shortened deceleration lane in Kenmare Avenue.
Firstly vehicles that enter the deceleration lane at full speed have insufficient distance
to slow down safely to the correct navigation speed to turn left into Kenmare Avenue
which increases the risk of rear-end accidents in the left turn deceleration lane.
Secondly with the presence of the bus stop at the entry to the shortened deceleration
lane, there is an increased risk of side swipe incidents between buses leaving the
bus stop and vehicles seeking to overtake the bus then turn left into the deceleration
lane.
Recommendation
The designer should either relocate the bus stop, place the bus stop within the
deceleration lane as per the design across the road where the bus stop is being
placed within an extended left turn deceleration lane for Hume Road intersection and
provide a correct length deceleration lane or remove the deceleration lane and force
vehicles to turn left from the kerbside lane. The provision of a shortened deceleration
lane that does not meet minimum standards is an additional hazard that should be
designed out.
[IMPORTANT | HIGH]
2.2 Finding – Proximity and Angle of the Spencer Road Service Road Access / Egress to the Bus Stop west of Kenmare Avenue
The proposed service road access / egress is directly behind the proposed bus stop
on Spencer Road on the approach to the Kenmare Avenue intersection. In the
present configuration with a shortened left turn deceleration lane, this creates a
conflict point with a higher percentage of vehicles performing a two-lane overtaking
manoeuvre during peak periods when buses are stationed in this bus stop than is
necessary for improved safety.
The angle of the entry of the service road to Spencer Road places vehicles exiting
from houses west of the egress in a position where they may be required to use their
rear view mirrors to judge speeds of oncoming traffic (heading eastbound in Spencer
Road). Angles of entry less than 70 degrees should be avoided in situations like this
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 9 | P a g e
as the decreased angle can promote higher speed entries from the service road than
intended. For houses east of the proposed access / egress (i.e. Lots 503 and 504)
this places their vehicle in a position where they are almost facing oncoming traffic
and will be required to perform a hook turn.
Justification of the finding:
Vehicles leaving this service road location will need to cross two lanes of traffic to
enter Spencer Road while a bus is parked in the proposed bus stop. In the first
paragraph describe the potential crash outcome related to the finding. E.g. There is a
risk of vehicles failing to give way whilst exiting the intersection which could result in
right angle crashes.
For vehicles that can exit the service road location when a bus is not present, the
current design allows for potentially higher speed exits due to the low angle entry to
Spencer Road. Whilst this design has the effect of being easy to navigate and offers
improved vehicular flow, the potential for a vehicle to attempt to accelerate into
Spencer Road is now possible. Under the current design, this location now has a
series of “obstacles” for drivers in Spencer Road to consider inclusive of: -
A. Stationary buses at the bus stop on the approach to Kenmare Avenue;
B. Vehicles seeking to overtake a stationary bus and cross two lanes of traffic into
the shortened Kenmare Avenue deceleration lane to turn left, whom may be
required to decelerate in the median-side lane;
C. Vehicles entering at differing speeds pending their house of origin from the
service road.
With relation to vehicles from Lots 503 and 504, this design points these vehicles at
an angle which is almost oncoming to vehicles in Spencer Road heading eastbound
towards Gosnells. This provides a fourth conflict within a 15 metre area on Spencer
Road and increases the chances of: -
side swipe incidents between vehicle – vehicle and vehicle – bus
rear end incidents between vehicles exiting the service road and stationary
buses, or decelerating vehicles seeking to enter the left turn deceleration lane
to Kenmare Avenue
right angle to head-on incidents between vehicles that appear to be oncoming
to eastbound traffic in Spencer Road exiting Lots 503 and 504.
Recommendation
The designer should either provide a correct length left turn deceleration lane with the
bus stop within the deceleration lane as per the bus stop on the opposite side of
Spencer Road which is located within the left turn deceleration lane approach to the
intersection of Regency Drive, or provide no deceleration lane for entry to Kenmare
Avenue. The designer should request SIDRA analysis of the intersection of Spencer
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 10 | P a g e
Road and Kenmare Avenue to determine the number of daily left turn movements
into Kenmare Avenue, as the vehicular volumes may be low enough to justify the
removal of the left turn deceleration.
With relation to the angle of access from the service road and its proximity to the bus
stop, the designer should remodel the angle of access such that it has a minimum
entry of 70 degrees for eastbound vehicles into Spencer Road. This adjustment of
entry angle will also alleviate vehicles from Lots 503 and 504 entering Spencer Road
at an angle that more represents an angle of oncoming traffic.
[IMPORTANT | HIGH]
2.3 Finding – Provide Left-In / Left-Out Splitter Island at intersection of Princeton Court and Spencer Road Service Road
The allowance of left and right-turn movements from Princeton Court into the Service
Road is unnecessary and adds a widening of the service road that is unnecessary.
This service road should be modified such that it is westbound only, improving safety
and both within the service road environment and providing a clear flow for vehicles
to join Spencer Road. Further, the service road at present on the southern side of
Spencer Road appears to be partially two-way and partially one-way which presents
conflicts where a driver becomes confused with the section of service road where the
intent changes from two-way traffic to one-way only. This comment applies for the
service road intersections of Princeton Court, Regency Drive and Grenadier Drive.
Justification of the finding:
The partial operation of this service road as a two-way service road between the
intersections of Princeton Court, Regency Drive and Grenadier Drive enables traffic
flow internally between these roads, however presents a potential issue for drivers
who seek to enter Spencer Road through a short section of one-way service road
east of Grenadier Drive. Due to the length of the service road, having three changes
of configuration between one-way, two-way and back to one-way again over a length
of approximately 200 metres develops a location where conflicts such as head-on
crashes could become an issue due to vehicles attempting to head east bound from
Princeton or Regency deciding to continue illegally through a short section of one-
way east of Grenadier.
Recommendation
Provide left in-left out median splitter islands at the intersection of Princeton,
Regency and Grenadier and re-design the service road in this location to be one-way
only with flow towards the west.
[IMPORTANT | HIGH]
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 11 | P a g e
2.4 Finding – Provide Left-In / Left-Out Median Splitter Island at intersection of Regency Drive and Spencer Road Service Road
This Finding is similar to Finding No 2.3. The allowance of a full movement
intersection at this location and the design of a partial one-way and two-way service
road generates potential conflicts between vehicles entering and exiting the service
road.
Justification of the finding:
The partial operation of this service road as a two-way service road between the
intersections of Princeton Court, Regency Drive and Grenadier Drive enables traffic
flow internally between these roads, however presents a potential issue for drivers
who seek to enter Spencer Road through a short section of one-way service road
east of Grenadier Drive. Due to the length of the service road, having three changes
of configuration between one-way, two-way and back to one-way again over a length
of approximately 200 metres develops a location where conflicts such as head-on
crashes could become an issue due to vehicles attempting to head east bound from
Princeton or Regency deciding to continue illegally through a short section of one-
way east of Grenadier.
Recommendation
Provide left-in / left-out median splitter islands at the intersections of Princeton Court,
Regency Drive and Grenadier Drive to the Spencer Road service road and re-design
the service road as one-way westbound only.
[IMPORTANT | HIGH]
2.5 Finding – Provide Left-In / Left-Out Median Splitter Island at intersection of Grenadier Drive and Spencer Road Service Road
This finding is similar to Findings 2.3 and 2.4. The allowance of a full movement
intersection at this location and the design of a partial one-way and two-way service
road generates potential conflicts between vehicles entering and exiting the service
road.
Justification of the finding:
The partial operation of this service road as a two-way service road between the
intersections of Princeton Court, Regency Drive and Grenadier Drive enables traffic
flow internally between these roads, however presents a potential issue for drivers
who seek to enter Spencer Road through a short section of one-way service road
east of Grenadier Drive. Due to the length of the service road, having three changes
of configuration between one-way, two-way and back to one-way again over a length
of approximately 200 metres develops a location where conflicts such as head-on
crashes could become an issue due to vehicles attempting to head east bound from
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 12 | P a g e
Princeton or Regency deciding to continue illegally through a short section of one-
way east of Grenadier.
Recommendation
Provide left-in and left-out median splitter islands to the intersections of Princeton
Court, Regency Drive and Grenadier Drive with the Spencer Road service road and
re-design the service road as a one-way westbound service road only.
[IMPORTANT | HIGH]
2.6 Finding – Glyndebourne Avenue Left-Turn Deceleration Lane is too short
The proposed left-turn deceleration lane into Glyndebourne Avenue is too short and
does not meet Austroads Guidelines for the Spencer Road speed environment.
Justification of the finding:
The proposed short left turn deceleration lane into Glyndebourne Avenue is too short
and does not meet Austroads Guidelines for the speed environment in Spencer Road
for deceleration to enter Glyndebourne Avenue.
Recommendation
The shortened deceleration lane is insufficient for safe deceleration and may lead to
increased rear-end accidents for vehicles seeking to turn left into Glyndebourne
Avenue. The deceleration lane should either be extended to meet the correct length
or removed in its entirety allowing vehicles to decelerate safely in the kerbside lane in
Spencer Road.
[IMPORTANT | HIGH]
2.7 Finding – Left-Out Aisle Width at Kenmare Avenue Median Splitter Island is too wide
The left-out aisle width at the intersection of Kenmare Avenue appears to be wide
and may promote excessive vehicular speeds through the intersection and into
Spencer Road. In our opinion, the road upgrades are to improve the vehicular flow
within Spencer Road and that all intersecting roads to Spencer Road within the
project area should be controlled with a yield (either Give Way or Stop) and vehicular
speeds controlled into Spencer Road. The designers should consider further options
to control both vehicular speeds from Kenmarke Avenue and direct access / egress
to Kenmare Avenue give the likely traffic volumes.
Justification of the finding:
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 13 | P a g e
Excessive vehicular speeds and vehicles failing to give way whilst exiting this
intersection has the potential to increase both the volume of side swipe and rear end
incidents for left-out traffic, with increased potential for right-angle crash incidences
for vehicles exiting Kenmare Avenue and attempting to enter the median-side lane in
Spencer Road. In addition, the severity of such incidences described above may also
be increased due to the increased potential exiting speed of vehicles from Kenmare
Avenue. As described above, the integrity, form and function of Spencer Road needs
to be the highest priority in this design as Spencer Road forms an important regional
connection between Cannington and Gosnells picking up the majority of the traffic
through Thornlie.
Recommendation
A number of Findings in this RSA can be addressed if the following design
amendment is considered by the designers: -
Option A – close the intersection of Kenmare Avenue with Spencer Road and
reconstruct an intersection with the Spencer Road service road.
This option will address previous commentary with relation to the number of access /
egress points to Spencer Road over a short length of road. In our opinion the number
of access / egress points in the design is too high and not in accordance with Main
Roads WA Guidelines for the design of major regional roads such as Spencer Road.
This project provides the opportunity to rationalise the number of access / egress
points to Spencer Road and in the opinion of the auditors this should be viewed by
the designers a key factor of success for this upgrade and enhancement project. The
rationalisation of access / egress points in this area would also improve safety for
buses and on-street cyclists in Spencer Road.
This design option would close three points of access / egress between Burnley
Street and Glyndebourne Avenue which in the opinion of the RSA audit team would
be a strong improvement to legibility, improve safety and allow for the development of
a one-way service road that improves general traffic flow for both the residents of
Spencer Road on the northern side of Spencer Road between Burnley Street and
Glyndebourne Avenue. This proposal also allows for the existing bus stop to be
maintained on the approach side to the Kenmare Avenue intersection and to have no
conflicts with left -turning traffic into Kenmare Avenue, plus allows for the construction
of an improved left-turn deceleration lane into Glyndebourne Avenue which will be
addressed in the next Finding.
Further, this would remove the necessity for the westbound hook turn on Spencer
Road. Motorists wanting to access Kenmare Avenue from Gosnells can easily access
Kenmare Avenue via Glyndebourne Avenue with minimal increase in trip time, whilst
greatly improving the form and function of Spencer Road in this location. A detailed
SIDRA analysis model would be required to verify these amendments, but we believe
this option is the best option to consider to rectify each of the issues represented in
the Findings.
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 14 | P a g e
Option B – address the width of the aisle and the design of the median splitter
island at the intersection of Kenmare Avenue and provide a Give Way or Stop
yield at the intersection to highlight the road hierarchy.
[IMPORTANT | HIGH]
2.8 Finding – Left-Out Aisle Width at the Intersection of Glyndebourne Avenue is too Wide
Similar to Finding 2.7 above, the present angle of the median splitter island promotes
vehicular egress from Glyndebourne Avenue at a range of angles between
approximately 85 degrees and down to 45 degrees. In the opinion of the RSA
auditors this angle and width is too wide and the intersection control is insufficient to
slow approaching vehicles from Glyndebourne Avenue to the desired speed
environment.
Justification of the finding:
Excessive vehicular speed from Glyndebourne Avenue for left-out movements
increases the potential for, and the severity of side swipe and rear-end accidents in
Spencer Road and increases the potential of right-angle incidents with vehicles from
Glyndebourne Avenue accessing the median-side lane.
Recommendation
The designers should review the splitter island median design to provide both a
suitable Give Way or Stop Yield and to provide a median splitter island design hat
points exiting vehicles at an angle of between 80 degrees and 75 degrees to a
minimum of 55 degrees whilst accommodating minimum aisle widths.
[IMPORTANT | LOW]
2.9 Finding – Left-Out aisle width at the Intersection of Denham Way is too wide
Similar to Findings 2.7 and 2.8 above, the present angle of the median splitter island
promotes vehicular egress from Denham Way at a range of angles between
approximately 85 degrees and down to as low as 45 degrees. In the opinion of the
RSA auditors this angle and width is too wide and the intersection control is
insufficient to slow approaching vehicles from Denham Way to the desired speed
environment.
Justification of the finding:
Excessive vehicular speed from Glyndebourne Avenue for left-out movements
increases the potential for, and the severity of side swipe and rear-end accidents in
Spencer Road and increases the potential of right-angle incidents with vehicles from
Glyndebourne Avenue accessing the median-side lane.
Recommendation
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
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KC01103.000 15 | P a g e
The designers should review the splitter island median design to provide both a
suitable Give Way or Stop Yield and to provide a median splitter island design that
points vehicles at and angle of between 75 degrees and 80 degrees at the splitter
island and up to a minimum of 50 degrees at the kerb return.
[IMPORTANT | LOW]
2.10 Finding – The number of access / egress points to Spencer Road on the northern side of the road between Glyndebourne Avenue and Denham Way is too high and should be rationalised.
As previously stated in the Findings, the RSA audit team sees this project as an
excellent opportunity to rationalise the number of access / egress points on Spencer
Road and to improve overall safety and function not just for vehicles, but also for
buses, pedestrians and cyclists within the overall road environment. East of
Glyndebourne Avenue these is no service road, therefore the present design allows
direct access / egress for four private properties fronting Spencer Road west of
Denham Way.
Justification of the finding:
Increased vehicular access / egress points to a road of the regional importance of
Spencer Road increases the risk of side swipe and rear end accidents for left-in and
left-out turning movements.
Recommendation
The number of access / egress points in this location can be rationalised, delivering a
major improvement to road safety and function of Spencer Road. The following
options are recommended: -
Provide a service road to allow one-way (eastbound) access to Lot 194 to Lot
190 on the western approach to Denham Way)
Option A – continue the service road through the Denham Way intersection,
thereby closing the intersection of Denham Way directly to Spencer Road and
bring the service road egress either to Lot 183 as part of this stage of the
works, or if in the opinion of the design team it is safer to bring the egress
past the intersection of Regal Drive (to ensure the egress is not utilised for
unintentional 4-way movement at the intersection of Spencer Road and Regal
Drive, extend the service road past the intersection of Regal Drive to Lot 179.
Option B – Terminate the Service Road at a distance sufficient west of
Denham Way intersection to allow the installation of a correct length
deceleration lane should the City of Gosnells design team prefer Denham
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 16 | P a g e
Way intersection is maintained with direct Left-In / Left-Out access egress to
Spencer Road.
The City of Gosnells should confirm SIDRA Analysis of current intersection
performance and modelling of road closures has been undertaken previously. In the
event that it has not previously been undertaken, we recommend that a detailed
SIDRA analysis model is developed to allow the City of Gosnells to develop improved
decision-making in this project.
[IMPORTANT | HIGH]
2.11 Finding – The Left Turn Deceleration Lane to Denham Way has insufficient length
The proposed left turn deceleration lane has insufficient length to allow vehicles
decelerate safely.
Justification of the finding:
The proposed short left turn deceleration lane into Denham Way is too short and
does not meet Austroads Guidelines for the speed environment in Spencer Road for
deceleration to enter Denham Way.
Recommendation
The shortened deceleration lane is insufficient for safe deceleration and may lead to
increased rear-end accidents for vehicles seeking to turn left into Denham Way from
Spencer Road. The deceleration lane should either be extended to meet the correct
length or removed in its entirety allowing vehicles to decelerate safely in the kerbside
lane in Spencer Road. Or, as per the recommendations in Finding 2.10 the
intersection of Spencer Road and Denham Way should be removed in its entirety and
replaced with a service road that rationalises the number of access / egress points
between Lots 194 to 190 and Lots 184 to 178. In this location the designers therefore
have the opportunity to rationalise 11 driveway crossover points of access / egress
plus a Left-In / Left-Out intersection (i.e. 12 points of access / egress) to 1 left-in
access near Lot 194 Spencer Road and 1 left-out egress near Lot 178 Spencer
Road. In our opinion this rationalisation of access egress is the safest system
available.
[IMPORTANT | HIGH]
2.12 Finding – Rationalise the number of hook turns provided for westbound traffic from Gosnells in Spencer Road
The present design shows three hook turns at the following locations: -
a. west of Kenmare Avenue
b. west of Glyndebourne Avenue
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 17 | P a g e
c. west of Denham Way
As previously mentioned in the Findings, the RSA audit team believe this project is
an excellent opportunity for the City of Gosnells to rationalise the number of conflict
points on Spencer Road. The number of hook turns should be reduced to one, with
the most logical west of the intersection of Glyndebourne Avenue or west of Kenmare
Avenue to allow for right turn movements from the service road that distributes traffic
from properties south of Spencer Road between Regency Drive and Grenadier Drive.
Justification of the finding:
The proposed hook turns increase the potential for right-angled crashes in Spencer
Road.
Recommendation
In the opinion of the RSA audit team, the number of hook turns for westbound traffic
in Spencer Road should be reduced from the present three (3), to one (1). The most
logical location for the one hook turn is to the west of Kenmare Avenue which allows
for right turn opportunities for vehicles exiting the service road south of Spencer
Road. The hook turn then also services Glyndebourne Avenue movements.
[IMPORTANT | HIGH]
2.13 Finding – No left-turn splitter island in left turn deceleration lane at the intersection of Spencer Road and Grenadier Drive (south)
This Finding is repeated from the previous Road Safety Audit. The lack of a splitter
island increases the chances for side swipe and / or 90-degree crashes between
vehicles entering Grenadier Drive (south) from Spencer Road and enables vehicles
to enter the Spencer Road service road between Grenadier Drive and Regency Drive
from the left turn deceleration lane. In our opinion this design option is unacceptable
for the following reasons: -
A. This design allows for two-way movement in the service road between Grenadier
Drive and Regency Drive on the southern side of Spencer Road. The auditors
believe the service road should be one-way only to increase safety and to remove
unnecessary conflicts.
B. The design for two-way movement in the service road between Grenadier Drive
and Regency Drive necessitates an unnecessary widening of the intersection of
Grenadier Drive (south) and Spencer Road.
C. This unnecessary widening allows for vehicles to access / egress this intersection
in a configuration that resembles a 6-way intersection.
Justification of the finding:
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
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KC01103.000 18 | P a g e
Increased chance of side swipe and / or 90-degree crashes in Grenadier Drive
(south) due to lack of median splitter island. The opportunity for vehicles to interact at
this intersection as follows should be considered unacceptable: -
a. to access the service road from the Spencer Road left-turn deceleration lane
(westbound into Grenadier Drive) adds potential for right-angle incidents with
vehicles that are either approaching the intersection from Grenadier Drive
(northbound) or for vehicles entering Grenadier Drive in a right turn from Spencer
Road (eastbound)
b. to access the service road from the Spencer Road left-turn deceleration lane
(westbound into Grenadier Drive) adds potential for a head-on crash with vehicles
heading eastbound from the service road into Grenadier Drive / Spencer Road
intersection.
c. for vehicles heading eastbound from the service road into the Grenadier Drive /
Spencer Road there is insufficient room in the service road and insufficient offset to
Spencer Road to line the vehicle up correctly at the intersection for a right turn
movement. It is highly likely under this design that a vehicle can enter Spencer Road
at an angle of less than 45 degrees, which limits sight distances to the west and
introduces the potential for right angle to head on incidents for westbound vehicles in
Spencer Road and side swipe / rear end incidents in Spencer Road eastbound.
d. for vehicles heading eastbound from the service road into the Grenadier Drive /
Spencer Road there is insufficient room in the service road and insufficient offset to
Spencer Road for vehicles to turn sufficiently to be able to turn left into Spencer Road
and travel westbound towards Cannington.
Recommendation
This design option is poor and it is highly recommended that this design option does
not proceed any further than this Preliminary design phase. It is deficient in so many
respects due to it effectively being a 6-way intersection with insufficient control and
points vehicles incorrectly towards lanes and provides a series of conflicts that should
be considered unacceptable.
[IMPORTANT | HIGH]
2.14 Finding – Location of Existing Lighting and Power Poles through the Project Area
This Finding is repeated from the previous Road Safety Audit.
Justification of the finding:
There are a significant number of night-time incidents on Spencer Road and the
lighting condition of the road at present is sub-standard for the number of vehicles
utilising this regional distributor. The existing location of the poles immediately
adjacent to the eastbound kerbline has the affect of impact sight distances to
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 19 | P a g e
intersections and provides a series of additional hazards along the length of the
project for eastbound vehicles in Spencer Road.
Recommendation
Lighting should be a high priority in the next iteration of design, with removal of power
poles within 1 metre of the proposed eastbound kerb line on the northern side of
Spencer Road.
[IMPORTANT | HIGH]
2.15 Finding – Provision of a full-movement intersection west of Kenmare Road to the Spencer Road service road
The provision of a full-movement intersection at this location immediately west of the
intersection of Kenmare Avenue rationalises the number of access / egress points by
removing the hook turn east of Kenmare Avenue, however provides the following
issues with the configuration of the service road on the southern side of Spencer
Road: -
A. forces a full-length two-way service road on the southern side of Spencer Road
B. does not show a suitable median splitter island to prevent vehicles accessing /
egressing the intersection on the wrong side of the road
C. does not address the priority of vehicles in either direction (west or east) of the
intersection within the service road.
Justification of the finding:
The provision of a full movement in this location requires significant internal
management within the service road to denote which users have priority to enter the
intersection first (either vehicles from the west or the east of the intersection within
the service road should be given priority to enter first). Given the service road only
appears to provide vehicular access / egress to Lot 112 Regency Drive, the priority
should be given to vehicles entering from the east.
The safety issues with this intersection configuration include: -
a. The lack of delineation for vehicles exiting / entering the intersection allows
vehicles to enter / exit on the wrong side of the road which increases the potential
for head-on incidents through the intersection
b. The lack of appropriate distance within the service road for 90 degree turns
impacts sight distances for right turn movements across Spencer Road,
particularly for vehicles exiting westbound from the Service Road. In this regard,
the auditors believe the City of Gosnells design is the better option with reduced
vehicular movements at this location minimising conflicts.
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
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KC01103.000 20 | P a g e
Recommendation
The service roads should be designed with minimised allowed vehicular movements,
due to the short development distance for vehicles to access / egress at 90 degrees
to the intersection given the proximity of the service road to the kerbside lane in
Spencer Road.
The auditors believe that the City of Gosnells design in this location is more
appropriate with minor amendments as described in the City of Gosnells Rev B
Option.
should be a high priority in the next iteration of design, with removal of power poles
within 1 metre of the proposed eastbound kerb line on the northern side of Spencer
Road.
[IMPORTANT | HIGH]
2.16 Finding – Short sharp change in horizontal geometry on Spencer Road kerb string near Lot 193
The design shows a short, sharp change in horizontal geometry on Spencer Road
kerbside (eastbound) in front of Lot 193. The only reason the auditors can see for this
change in horizontal geometry is either an error in the design, or a localised widening
due to the presence of the hook turn.
Justification of the finding:
The change in horizontal geometry is too short and sharp to be suitable for Austroads
Guide to Road Design for the vehicular volumes and the speed environment. Such
short, sharp changes of horizontal alignment are a surprise to drivers and may
contribute to increased side-swipe incidents through drivers reacting to the change in
geometry by changing lanes or not following the road alignment. The presence of this
change in road alignment coinciding with a location where a hook turn is introduced
provides two hazards for eastbound drivers in Spencer Road to negotiate in the one
location.
Recommendation
The change in horizontal geometry is unnecessary and should be removed as a
minimum. The designers should review the Findings and Recommendations in the
City of Gosnells Design Option B report where it was noted that the number of hook
turns in this project should be reduced to one (i.e. this hook turn should be removed)
and that the number of vehicular access / egress points between Glyndebourne
Avenue and properties east of Denham Way should be reduced from 12 to 2.
[IMPORTANT | HIGH]
OCM 17 DECEMBER 2019 APPENDIX 13.3.1E
KCTT (Trading as Traffic and Transport Pty Ltd) | ABN: 35 148 970 727 | PERTH: 7 / 10 Whipple Street Balcatta WA 6021 | BELGRADE: 23 Hilandarska, Beograd 11000 | | PHONE: 08 9441 2700 | EMAIL: [email protected] | WEB: www.kctt.com.au |
KC01103.000 21 | P a g e
3. AUDIT TEAM STATEMENT
I hereby certify that the audit team have examined the documents listed in
Appendix C in undertaking this Road Safety Audit and confirm that this audit has
been carried out independently of the design team and in accordance with Main
Roads Policy and Guidelines for Road Safety Audit.