low cost safety improvements hindmarsh drive, melrose drive, wentworth avenue & kuringa drive

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Low Cost Safety Improvements Roads ACT 27 November 2012 D R A F T Document No. 60271823RPTRA001_2

Low Cost Safety Improvements Hindmarsh Drive, Melrose Drive, Wentworth Avenue & Kuringa Drive

AECOM Low Cost Safety Improvements Low Cost Safety Improvements - Hindmarsh Drive, Melrose Drive, Wentworth Avenue & Kuringa Drive

D R A F T

P:\CBR\60271823_LowCostSafety_Imprvmnts2012\8. Issued Docs\8.1 Reports\60271823RPTRA001_2.docx Revision 2 - 27 November 2012

Low Cost Safety Improvements Hindmarsh Drive, Melrose Drive, Wentworth Avenue & Kuringa Drive

Prepared for

Roads ACT

Prepared by AECOM Australia Pty Ltd Level 2, 60 Marcus Clarke Street, Canberra ACT 2600, Australia T +61 2 6201 3000 F +61 2 6201 3099 www.aecom.com ABN 20 093 846 925

27 November 2012

60271823

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Quality Information Document Low Cost Safety Improvements

Ref 60271823

Date 27 November 2012

Prepared by Leigh Palmer, Michael Jollon

Reviewed by Tim Rampton

Revision History

Revision Revision Date Details

Authorised

Name/Position Signature

1 10-Aug-2012 Draft Report Tim Rampton Associate Director

2 27-Nov-2012 Final Draft Report Tim Rampton Associate Director


D R A F T


Table of Contents Executive Summary i 1.0 Introduction 4

1.1 Overall objective 4 1.2 Project tasks 4

2.0 Hindmarsh Drive/ Launceston Street and Hindmarsh Drive/ Eggleston Crescent 5 2.1 Review of previous studies 5 2.2 Results of modelling safety improvements 6 2.3 Low cost safety measures 7 2.4 Expected crash reductions 8 2.5 Economic Analysis 8 2.6 Recommendation 9

3.0 Melrose Drive / Theodore Street 10 3.1 Background 10 3.2 Updated crash analysis 10 3.3 Traffic characteristics 13 3.4 Site inspection 15 3.5 Remedial measures 16 3.6 Expected crash reductions 17 3.7 Economic analysis 17 3.8 Recommendation 19

4.0 Wentworth Avenue / Mildura Street / Leichhardt Street 20 4.1 Background 20 4.2 Crash analysis 20 4.3 Traffic characteristics 23 4.4 Site inspection 25 4.5 Remedial measures 26 4.6 Expected crash reductions 27 4.7 Economic analysis 27 4.8 Existing deficiencies and maintenance items 29 4.9 Recommendation 29

5.0 Kuringa Drive 30 5.1 Background 30 5.2 Updated crash analysis 30 5.3 Traffic characteristics 33 5.4 Site inspection 37 5.5 Remedial measures 39 5.6 Expected crash reductions 42 5.7 Economic analysis 42 5.8 Existing deficiencies and maintenance items 44 5.9 Recommendation 44


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List of Tables

Table 1 Summary of Benefit to Cost Analysis Hindmarsh Drive / Launceston Street 5 Table 2 Summary of Benefit to Cost Analysis Hindmarsh Drive / Eggleston Crescent 6 Table 3 Benefit/cost analysis Hindmarsh Drive 9 Table 4 Crash comparison before and after treatment Melrose Drive / Theodore Street 10 Table 5 Updated crash history Melrose Drive / Theodore Street 11 Table 6 Crash factor matrix Melrose Drive / Theodore Street 12 Table 7 Benefit/cost analysis Melrose Drive / Theodore Street 18 Table 8 Crash comparison before and after treatment Wentworth Avenue / Mildura Street /

Leichhardt Street 20 Table 9 Updated crash history Wentworth Avenue / Mildura Street / Leichhardt Street 21 Table 10 Crash factor matrix Wentworth Avenue / Mildura Street / Leichhardt Street 22 Table 11 Benefit/cost analysis Wentworth Avenue / Mildura Street / Leichhardt Street 28 Table 12 Crash comparison before and after treatment Kuringa Drive 30 Table 13 Updated crash history Kuringa Drive 31 Table 14 Crash factor matrix for Kuringa Drive 32 Table 15 Benefit/cost analysis Kuringa Drive 43

List of Figures

Figure 1 Option 1 b – Lane reduction on Hindmarsh Drive 6 Figure 2 Enhanced speed limit and side road warning signs for Hindmarsh Drive intersections 7 Figure 3 Additional signs at Launceston Street 8 Figure 4 Sign relocation at Eggleston Crescent 8 Figure 5 Melrose Drive/ Theodore Street 13 Figure 6 ACTION Weekday Bus Service 14 Figure 7 ACT Walking and Cycling Map: Melrose Drive / Theodore Street detail 15 Figure 8 Low-Cost Safety Option for Melrose Drive / Theodore Street 17 Figure 9 ACTMAPi aerial view of Wentworth Avenue / Mildura Street / Leichhardt Street 23 Figure 10 ACTION Weekday Bus Service 24 Figure 11 ACT Walking and Cycling Map: Wentworth Avenue detail 25 Figure 12 Low Cost Safety Improvements Wentworth Avenue / Mildura Street / Leichhardt Street 27 Figure 13 Kuringa Drive Source: Google Earth Pro 33 Figure 14 Kuringa Drive / Tillyard Drive Curve Source: ACTMAPi 34 Figure 15 Kuringa Drive back-to-back curves Source: ACTMAPi 34 Figure 16 Kuringa Drive / Kingsford Smith Drive Source: ACTMAPi 35 Figure 17 ACTION Weekday Bus Service 36 Figure 18 ACT Walking and Cycling Map: Kuringa Drive detail 36 Figure 19 Tillyard Street curve detail for RRPM treatment extents 39 Figure 20 Back to back curve detail for RRPM treatment extents 39 Figure 21 Kingsford Smith Drive curve detail for RRPM treatment extents 40 Figure 22 Enhanced speed limit marking on Kuringa Drive 40 Figure 23 Enhanced curve warning and speed signs on Kuringa Drive 41


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i

Executive Summary Roads ACT have commissioned AECOM Australia Pty Ltd to reinvestigate, analyse and provide recommendations for low-cost safety improvements at certain intersections on Hindmarsh Drive, Melrose Drive, Wentworth Avenue, and on the midblock segment of Kuringa Drive between Tillyard Street and Kingsford Smith Drive. These analyses included the examination of the most recently available five year crash history for each site to ascertain the contributory factors and develop remedial measures for each site.

Hindmarsh Drive / Launceston Street and Hindmarsh Drive / Eggleston Crescent Microsimulation modelling of a lane reduction option on Hindmarsh Drive

Black spot safety studies were completed for the intersections at Eggleston Crescent and Launceston Street in 2011 and 2012. An option (1b) was identified in the earlier study as a possible solution. It proposed to reduce the number of through traffic lanes along Hindmarsh Drive from the existing three lane layout to a two lane through movement at the intersection, with a dedicated continuous slip lane for right and left turners out of both intersections onto Hindmarsh Drive

In this study, the Option 1b lane reduction was modelled using Commuter microsimulation software. Simulation of the proposed lane arrangement indicated it will not provide adequate capacity to service the existing AM peak hour volumes.

An alternative lane arrangement (Option 1c) was considered which reduced the number of through lanes on the near side approach at each t-intersection: westbound Hindmarsh Drive at Eggleston Crescent and eastbound Hindmarsh Drive at Launceston Street. At the intersections an ‘add lane’ was formed to allow for right turners out of the side streets to have a dedicated lane on Hindmarsh Drive.

The model has indicated that the proposed changes as part of Option 1c would not cause any significant traffic issues along the corridor. Furthermore, this option will reduce the number of lanes required to be crossed (one-way) from three to two, in order to undertake a right turn. This in turn should improve the legibility to drivers and improve safety at the intersections.

Overall Option 1C provides a good balance between maintaining capacity along Hindmarsh Drive and safety improvements at the intersections of Launceston Street and Eggleston Crescent. As such, should be considered as a possible solution to the current safety concerns at the two intersections.

Low Cost Treatments

At the intersection of Hindmarsh Drive and Launceston Street, the following low cost safety measures were identified to improve existing safety conditions.

- Install side road warning signs on the nearside eastbound approach of Hindmarsh Drive

- Install enhanced speed limit signage on both directions of Hindmarsh Drive

Enhanced signage may include LED displays or larger signs

- Install a second Stop sign on the splitter island Launceston Street approach

- Install a Keep Right sign on the seagull island

At the intersection of Hindmarsh Drive and Eggleston Crescent, it is recommended to



- Relocate the Give Way warning sign on Eggleston Crescent to improve its visibility

The indicative implementation cost for this option is $15,000. Potential savings from crash reductions were computed, and a benefit/cost ratio of 2.63 was determined. This indicates the treatment would return over two and half times its cost in crash benefits.


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ii

The proposal for enhanced speed limit, priority and warning signs are recommended along Hindmarsh Drive at Launceston Street and Eggleston Crescent as a form of low cost improvement. Increased speed limit enforcement by both police and automated means, is also recommended.

However, it should be noted that higher safety improvement could be gained with more capital expenditure (e.g.: signalising the intersections) although investigation into this type of treatment was explored in the original study.

Melrose Drive / Theodore Street Safety improvements were made under the black spot program to the intersection of Melrose Drive and Theodore Street in late 2006. These improvements included re-alignment of the right turn and left turn entry into Theodore Street and construction of splitter Island to re-align entry into Melrose Drive. An assessment of the improvements was conducted by Roads ACT in 2010. A total increase of 140% in the number of crashes was detected at this intersection.

The recorded crashes for the five year period from January 2007 until December 2011 were analysed. Thirty-seven crashes have occurred at the intersection of Melrose Drive and Theodore Street. Of these crashes, 4 were injury crashes and the rest were property damage only crashes. Almost half, 18 of 37 crashes in the 5 year period involved vehicles turning right out of Theodore Street. Most of the crashes (65%) occurred outside of peak periods.

The proposed remedial measure for this intersection is enhancing intersection conspicuity with dual intersection warning signs on Melrose Drive, and marking the intersection on northbound Melrose Drive with a Keep Clear box.

The indicative implementation cost for this option is $15,000. Potential savings from crash reductions were computed, and a benefit/cost ratio of 2.78 was determined. This indicates the treatment would return over two and half times its cost in crash benefits.

The proposal for Intersection warning signs and a ‘keep clear’ is recommended on Melrose Drive as a form of low cost improvement.

However, it should be noted that higher safety improvement could be gained with more capital expenditure (e.g.: signalising the intersection) although investigation into this type of treatment was not explored in this study.

Wentworth Avenue / Mildura Street / Leichhardt Street Safety improvements were made in 2007 under the black spot program to the intersection of Wentworth Avenue, Mildura Street and Leichhardt Street. The improvements included installation of traffic islands, signs and line marking. An assessment of the improvements was conducted by Roads ACT in 2010.

There was one fatal adjacent approach crash in the after study period. Opposing turn collisions, lane side swipes and manoeuvring crashes all increased. An overall 8% increase in the total number of crashes was detected at this intersection after the treatment.

The recorded crashes for the five year period from January 2007 through December 2011 were analysed. Sixteen crashes have occurred at the intersection of Melrose Drive and Theodore Street in the five year period. Of these crashes, 1 was a fatal crash and the rest were property damage only crashes. Crashes were well distributed among types; however, 9 of 16 were right angle crashes from adjacent approaches.

The recommended low cost safety improvements at the intersection of Wentworth Avenue, Mildura Street and Leichhardt Street include:

- Reposition existing Give Way sign on Mildura Street closer to intersection

- Supply additional Give Way sign on the median island on Mildura Street

- Refresh paint and install Reflective Pavement Markers (RPM) for all median crosshatching in intersection.

The indicative implementation cost for this option is $15,000. Potential savings from crash reductions were computed, and a benefit/cost ratio of 1.34 was determined. This indicates the treatment would result in a crash reduction value only slightly greater than installation and maintenance costs.


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iii

Despite not meeting the desired ratio of benefits outweighing costs by a factor of two, the low cost safety improvements at Wentworth Avenue and Mildura Street / Leichhardt Street may still be considered for their ability to improve safety at the intersection. If the restriping of the approach islands and raised pavement markers are not initially installed, replacement of a second Give Way sign on the median of Mildura Street should be considered as a maintenance item.

Kuringa Drive Safety improvements were made under the black spot program to the mid-block section of Kuringa Drive between Tillyard Drive and Kingsford Smith Drive in June 2008. These improvements included Installation of warning signs, guardrails and lighting.

There were 23 crashes on this segment of Kuringa Drive in four year period after the treatment. These crashes include one fatality, 8 injury crashes, and 14 property damage crashes. The crash frequency is almost 8 crashes per year, an increase over the five crashes per year in the period studied before the treatment was installed.

The most common crash types were single vehicles leaving the roadway. The bulk of the crashes, 20 of 23, occurred in the westbound direction. About half were on wet roads. More than half occurred on weekends or public holidays.

The proposed remedial measures for this midblock road section are:

- Improve speed limit signage with larger signs at the beginning of the road segment and repeater signs along the road. To highlight the change in speed limit on the approach form the west, the speed limit should be marked in the westbound lane after Kingsford Smith Drive.

- Enhance curve warning and advisory speed signs by installing on both sides of the road leading into the back to back curve and repeating curve warning signs on both sides of the road in between back to back curves.

- Increase supply of retro-reflective raised pavement markers (RRPMs) by halving spacing along the centreline and edge lines approaching and through all signposted curves.

The indicative implementation cost for this option is $15,000. Potential savings from crash reductions were computed, and a benefit/cost ratio of 4.60 was determined. This indicates the treatment would return over four times its cost in crash benefits.

Existing deficiencies and maintenance items include: overgrown trees should be cut back, missing and damaged signs and guide posts should be replaced, and an eroded shoulder in the westbound lane should be repaired.

The proposal for enhanced speed limit signs and marking, curve warning signs and retro-reflective raised pavement markers is recommended for the mid-block section of Kuringa Drive between Tillyard Street and Kingsford Smith Drive as a form of low cost improvement. However, it should be noted that higher safety improvement could be gained with more capital expenditure (e.g. realignment) although investigation into this type of treatment was not explored in this study.

It should be noted that this form of treatment relies on a high level of driver compliance. As such, this location should be considered for increased speed enforcement. Extra attention should be given in the back to back curves. This enforcement should be focused on the westbound traffic, particularly on straight segments and in the back to back turns. Both police speed enforcement and automated speed enforcement means should be considered.


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1.0 Introduction Roads ACT have commissioned AECOM Australia Pty Ltd to reinvestigate, analyse and provide recommendations for low-cost safety improvements at intersections on Hindmarsh Drive, Melrose Drive and Wentworth Avenue, and on a midblock segment of Kuringa Drive. These analyses included the examination of the most recently available five year crash history for each site to ascertain the contributory factors and develop remedial measures for each site.

The following sites were examined.

Intersections

1. Hindmarsh Drive / Launceston Street

2. Hindmarsh Drive / Eggleston Crescent

3. Melrose Drive / Theodore Street

4. Wentworth Avenue / Mildura Street / Leichhardt Street

Mid-Block Locations

1. Kuringa Drive between Kingsford Smith Drive and Tillyard Drive Crescent

1.1 Overall objective The ACT Road Safety Strategy for 2011 – 2020 aims to meet a national goal of at least a 30% reduction in fatalities and serious injuries by 2020. Providing safe roads and roadsides is one component of an integrated approach to meet this goal. Our study will provide the ACT Government with cost effective and safe upgrade options which will allow for informed recommendations to be made. The aim of the project is to: - Identify the contributory factors associated with crashes at each site

- Identify any features seen during site inspections, which may adversely contribute to crashes at this location

- Suggest remedial measures

1.2 Project tasks For the Hindmarsh Drive locations:

- previous studies have been reviewed

- recommended options have been modelled through computer aided micro-simulation to determine their ability to serve existing and expected future volumes of traffic

- additional low cost safety improvements have been explored for implementation in lieu of the modelled options.

For the re-investigations of intersections on Melrose Drive and on Wentworth Avenue, and Kuringa Drive:

- updated analysis has been performed on the last five years of crash data

- crash factor matrices have been developed

- low-cost countermeasures have been developed

- preferred countermeasures have been recommended


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5

2.0 Hindmarsh Drive/ Launceston Street and Hindmarsh Drive/ Eggleston Crescent

2.1 Review of previous studies Crash Analysis

The crash analysis performed for the Hindmarsh Drive and Launceston Street intersection indicated that 27 crashes occurred during the five year period January 2006 to December 2010. Of these crashes, three (11%) were injury crashes and 24 were property damage crashes. A large proportion of crashes (10 of 27) were right angle (adjacent approach) crashes—all of these involved right turns out of Launceston Street. This movement was also implicated in two of the three injury crashes.

At the Hindmarsh Drive and Eggleston Crescent intersection, there were 32 recorded crashes in the period January 2006 to December 2010. Of these crashes, four (12.5%) were injury crashes and the rest were property damage only crashes. The greatest number of crashes were rear-end collisions. All injury crashes were the result of adjacent approach crashes. Half of the adjacent approach crashes and 40% of the rear-end crashes involved the left turn out of Eggleston Crescent.

Site Inspection

The observations noted at Hindmarsh Drive and Launceston Street included:

- Sight distance is reasonable at the intersection; however it seems that drivers turning right out of Launceston Street don’t select a safe gap, possibly due to difficulty detecting gaps in three lanes on Hindmarsh Drive.

- Right turn movements out of Launceston Street don’t have a dedicated acceleration lane in the median on Hindmarsh Drive; this may result in frustration and taking unsafe gaps particularly in peak hours.

- There are missing connecting footpaths on either side of Launceston Street.

- Pavement has deteriorated at Launceston Street particularly on the left turn lane from Hindmarsh Drive.

- The relatively straight alignment and pavement width of Hindmarsh Drive tends to invite a higher operational speed than the posted 80 km/h.

The observations noted at Hindmarsh Drive and Eggleston Crescent included:

- The majority of turning movements at the intersection are right turn movements into Eggleston Crescent and left turn movements out of Eggleston Crescent (in the PM)

- Many drivers turning right into Eggleston Crescent use Eggleston Crescent to connect to other Woden Valley suburbs via Macfarlane Crescent.

- Drivers turning right into and out of Eggleston Crescent may misjudge the gap crossing three lanes which are travelling at 80 km/h.

- Sight lines of vehicles in the left turn lane out of Eggleston Crescent can be obscured by vehicles turning right. This may result in hesitation and may be a factor in rear-end crashes, as the driver of the second vehicle may have a better view than the drive of the lead vehicle.

Options Analysis

Each option was allocated an indicative implementation cost and assessed for potential crash reduction savings. The results of the cost benefit analysis for Hindmarsh Drive and Launceston Street are summarised in Table 1. Table 1 Summary of Benefit to Cost Analysis Hindmarsh Drive / Launceston Street

OPTION Treatment Cost B/C Ratio NPV

OPTION 1 Acceleration Lane $200,000 0.17 -$224,098

OPTION 2 Signalisation $525,000 0.51 -$344,055


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Both options failed to yield benefits in excess of their costs. As a result, neither of the options were considered viable for implementation.

The results of the cost benefit analysis for Hindmarsh Drive and Eggleston Crescent are summarised in Table 2. Table 2 Summary of Benefit to Cost Analysis Hindmarsh Drive / Eggleston Crescent

OPTION Treatment Cost B/C Ratio NPV

OPTION 1 a Lane reduction of Hindmarsh Drive at Eggleston Crescent $94,000 2.66 $210,765

OPTION 1 b Lane reduction of Hindmarsh Drive at Eggleston Crescent and at Launceston Street $230,000 2.09 $337,305

OPTION 2 Median closure with left turn deceleration / acceleration lanes $122,000 3.54 $419,354

OPTION 3

Closure of the subject intersection with installing new signalised intersection at Hindmarsh Dr / Launceston St. / MacDonald St $370,000 0.58 -$209,491

Options 1a reducing from three through lanes to two at Eggleston Crescent; and Option 1b, reducing from three through lanes to two at Eggleston Crescent and at Launceston Street were both regarded as viable options. Option 1b (see Figure 1), was recommended because it offered effective crash reductions for two intersections and maintained consistency and driver expectations.

Figure 1 Option 1 b – Lane reduction on Hindmarsh Drive

With traffic volumes on three lanes of Hindmarsh Drive estimated at 2,300 vehicles per hour in the peak direction, it was expected that the recommendation may increase safety without significantly increasing delays. However, it was noted that further analysis would need to be undertaken before implementation was considered.

2.2 Results of modelling safety improvements In this study, the Option 1b lane reduction was modelled using Commuter microsimulation software. Simulation of the proposed lane arrangement indicated it will not provide adequate capacity to service the existing AM peak hour volumes.

An alternative lane arrangement (Option 1c) was considered which reduced the number of through lanes on the near side approach at each t-intersection: westbound Hindmarsh Drive at Eggleston Crescent and eastbound Hindmarsh Drive at Launceston Street. At the intersections an ‘add lane’ was formed to allow for right turners out of the side streets to have a dedicated lane on Hindmarsh Drive.

The model has indicated that the proposed changes as part of Option 1c would not cause any significant traffic issues along the corridor. Furthermore, this option will reduce the number of lanes required to be crossed (one-


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7

way) from three to two, in order to undertake a right turn. This in turn should improve the legibility to drivers and improve safety at the intersections.

Overall Option 1C provides a good balance between maintaining capacity along Hindmarsh Drive and safety improvements at the intersections of Launceston Street and Eggleston Crescent. As such, should be considered as a possible solution to the current safety concerns at the two intersections.

2.3 Low cost safety measures At the intersection of Hindmarsh Drive and Launceston Street, possible low cost safety measures were identified to improve existing safety conditions.



Enhance signage may include LED displays or larger signs

- Install a second Stop sign on the splitter island Launceston Street approach (this approach is already controlled with a Stop sign)

- Install a Keep Right sign on the seagull island

At the intersection of Hindmarsh Drive and Eggleston Crescent, it is recommended to



- Relocate the Give Way warning sign on Eggleston Crescent to improve its visibility

Increased speed limit enforcement by both police and automated means, is recommended for both locations

Figure 2 Enhanced speed limit and side road warning signs for Hindmarsh Drive intersections

The estimate of probable cost to install this treatment is $15,000 excluding GST. No detailed design or assessment of the existing hardware or underground services has been undertaken.


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Figure 3 Additional signs at Launceston Street

Figure 4 Sign relocation at Eggleston Crescent

2.4 Expected crash reductions Expected crash reductions were tabulated by applying reductions available from road safety literature to the 5-year crash experience in the intersection. Where crash reductions were not available through research, engineering judgement and experience were used to determine potential benefits. Only crashes of the particular type identified through literature or by engineering judgment, and on the correct approach to be affected by the option, were considered targeted crashes for reduction. The results are detailed in the “Target Crashes” and “Assumed Reduction” columns in Table 3

The low cost safety improvement option, enhanced speed limit, priority and warning signs, should reduce adjacent approach (codes 101-109) and opposing turn crashes (codes 202-206) by 5%. This treatment should reduce the likelihood of 22 of 59 total crashes that occurred during the crash history period.

2.5 Economic Analysis The 2011 crash costs were obtained from Roads ACT to develop an economic analysis of the costs and benefits of low cost improvements. Crash cost by crash type was used for costing future crashes. When crash types were encountered that did not have indicative costs; the cost of an average property damage crash was substituted in the analysis.

The present-day value of the expected costs and benefits over a 10-year project life for the option were analysed. The results are detailed in Table 3.


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Table 3 Benefit/cost analysis Hindmarsh Drive

LOCATION: Hindmarsh Drive / Launceston St & Eggleston Crescent Low Cost Option

Discount rate 7% Enhanced Speed Limit, Priority and Warning Signs

Years of Crash Data 5 Initial Cost of Treatment $15,000

Assumed Project Life 10 Annual Maintenance $750

Crash Code Crash Description Tota

l C

rash

es

Cos

t per

C

rash

Cos

t of

Cra

shes

Targ

et

Cra

shes

Ass

umed

R

educ

tion

Dis

coun

ted

Ben

efits

101-109 Intersection, adjacent approaches 16 $35,265 $564,240 16 5% $39,630

201 Head-on 138,301 0

202-206 Opposing vehicles; turning 6 32,584 195,504 6 5% $13,731

301 - 304 Rear-end 30 19,909 597,270

305 - 307 Lane change 2 21,557 43,114

001 - 003 Vehicle hits pedestrian 163,946

706 - 707 Loss of Control (L or R turns) 82,427

401 - 402 Hit parked vehicle 21,586

601 Hit parked vehicle 23,675

501 - 506 Overtaking 28,113

901 Fell from moving vehicle 70,222

Other 5 18,096 90,480

TOTAL 59 $1,490,608 22 $53,361

B/C

Ratio NPV Discounted

Costs

2.63 $33,094 $20,268

The benefit to cost analysis indicates that the proposed low cost safety improvement has a Benefit/Cost Ratio of 2.63. This indicates the treatment would result in over two and half times the cost of improvements returned in crash benefits.

2.6 Recommendation The proposal for enhanced speed limit, priority and warning signs is recommended along Hindmarsh Drive at Launceston Street and Eggleston Crescent as a form of low cost improvement. Increased speed limit enforcement by both police and automated means, is also recommended.

However, it should be noted that higher safety improvement could be gained with more capital expenditure (e.g.: signalising the intersections) although investigation into this type of treatment was explored in the original study.


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3.0 Melrose Drive / Theodore Street

3.1 Background Safety improvements were made under the black spot program to the intersection of Melrose Drive and Theodore Street in late 2006. These improvements included re-alignment of the right turn and left turn entry into Theodore Street and construction of splitter Island to re-align entry into Melrose Drive. An assessment of the improvements was conducted by Roads ACT in 2010. The crash data for both the “before treatment’ and ‘after treatment’ crashes were compared. Table 4 Crash comparison before and after treatment Melrose Drive / Theodore Street

RUM Code

ACT Crash Type

Before (1/06/03 – 31/05/06)

After (1/12/06 – 30/11/09) Change

% Fatal Injury PDO Total Fatal Injury PDO Total

001-003 101-109 1, 2, 4 1 5 1 14 15 150 201 202-206 1 2 2 200 301-304 6 3 3 5 5 66.7 305-309 3, 9 2 2 200 401-408 8 1 1 -100 501-506 601-609 12 701-709 19 901 Totals 1 9 10 1 23 24 140

Table 4 outlines the increase and decrease in crashes before and after the treatment specific to the crash type and severity for each crash group.

Prior to treatment, the most dominant crash type was right angle collisions between vehicles from adjacent approaches (RUM 101-109). This increased by 150% after the application of treatment. Whilst the treatment eliminated manoeuvring crashes (401-408), it increased the number of right turn crashes between vehicles from opposing directions (202-206,) rear end collisions (301-304) and lane change collisions (RUM 305-309). A total increase of 140% in the number of crashes was detected at this intersection.

An increase in traffic volume, especially during the peak hours was considered to be a probable factor in the increased crash rate. This caused delays at the intersection, in particular the queuing of right turn vehicles on both roads, and may have encouraged more road users to take unnecessary risks in negotiating the intersection. This may have accounted for the increase in the adjacent and opposing approach crashes, as well as the increase in rear end crashes.

3.2 Updated crash analysis The recorded crashes were obtained from Roads ACT for the five year period from January 2007 until December 2011. The records indicate that 37 crashes have occurred at the intersection of Melrose Drive and Theodore Street. Of these crashes, 4 were injury crashes and the rest were property damage only crashes as shown in Table 5.


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Table 5 Updated crash history Melrose Drive / Theodore Street

Severity 2007 2008 2009 2010 2011 Total

Fatal - - - - - -

Admitted to Hospital

- - - - - -

Received Medical Treatment

- 1 - 1 2 4

Property Damage Only

8 13 2 2 8 33

Total 8 14 2 3 10 37

In the two-year period 2010 – 2011, 13 crashes were reported at the intersection. This crash frequency is in line with the four-year count of 24 crashes in 2006 – 2009. It should also be noted that 3 injury crashes were reported in this period, an increase over the previous analysis period.

A crash factor matrix has been prepared and is shown in Table 6. Almost half, 18 of 37 crashes in the 5 year period involved vehicles turning right out of Theodore Street. Most of the crashes (65%) occurred outside of peak periods.


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Table 6 Crash factor matrix Melrose Drive / Theodore Street

DCA Code On Street

Key Direct-ion

Year of Crash Total

Other Direction Surface Light

Conditions

Type of Day Weekday

Peak Period

2007

2008

2009

2010

2011

Nor

th

Eas

t

Sout

h

Wes

t

Dry

Wet

Day

Dar

k P

ublic

H

olid

ay

Wee

k - e

nds

Wee

k - d

ays

103 Theodore St ES 1 1 1 1 1

104

Melrose Dr NB 3 8 2 2 1 16 15 1 13 3 14 2 2 14 6

Theodore St NB 2 2 1 1 1 2 2

105 Melrose Dr SB 1 1 1 1 1 1

107

Theodore St SB 1 1 1 1 1 1

Melrose Dr NB 1 1 1 1 1 1

202 Melrose Dr SB 1 1 2 1 1 2 2 1 1 1

Theodore St SB 1 1 1 1 1 1

301 Theodore St SB 1 1 1 1 1

Melrose Dr NB 2 2 2 2 2 1

303 Theodore St ES 1 1 1 3 1 3 1 2 3 2

Melrose Dr SB 2 2 1 1 1 2 1 1

305 Melrose Dr NB 1 1 1 1 1 1

306 Melrose Dr NB 1 1 1 1 1

307 Theodore St NB 1 1 1 1 1 1

309 Melrose Dr NB 1 1 1 1 1 1

Total 10 13 2 2 10 37 2 20 2 1 30 7 31 6 0 5 32 13


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3.3 Traffic characteristics Intersection/Road geometry

Melrose Drive

Melrose Drive is a dual carriageway arterial road running north-south across the Woden District. It connects Yarra Glen / Yamba Drive to Athllon Drive and runs between the suburbs of Phillip, Chifley and Lyons. Melrose Drive is 6 lanes wide at its intersection with Theodore Street. The pavement width at this intersection is about 11 metres on each carriageway. Theodore Street

Theodore Street is a major collector road in Curtin connecting Melrose Drive to Carruthers Street and the Curtin Shops. It is a two lane undivided road. Approaching Melrose Drive the pavement width is about 12 metres. At the intersection the road widens to accommodate parking and turn lanes, a raised concrete median and splitter island. Intersection

The intersection is a seagull arrangement controlled by a ‘give way’ sign on Theodore Street. Right turn movements out of Theodore Street have a dedicated lane on Theodore Street but have no acceleration lane on Melrose Drive. Right turn movements out of Melrose Drive have a deceleration turn lane on Melrose Drive.

Figure 5 Melrose Drive/ Theodore Street

Source; ACTMAPi - ACT Government online interactive maps


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Traffic volume and speed

The ACT Traffic Volumes 2005 – 2007 report indicates that in 2005, Melrose Drive in the vicinity of Theodore Street was travelled by approximately 11,000 vehicles in each direction each weekday; with about 1,400 heading north in the AM peak hour, and 1,400 heading south in the PM peak hour.

The sign-posted speed limits on the roads approaching the intersection are as follows:

- 70 km/h on Melrose Drive

- 60 km/h on Theodore Street

Public transport

Many ACTION weekday bus services travel through the intersection, going to and from the Woden Bus Interchange. Melrose Drive carries routes 21, 22, all Blue Rapid 300 series and several Xpresso routes. Theodore Street carries route 2, 76, 77, 932, and 732. There are bus stops on each side of Melrose Drive, just south of the intersection as shown in Figure 6. These bus stops are among the busiest non-interchange bus stops in the ACT, with gaps between buses well under five minutes in peak hours. It is not unusual to see two or three buses stopping in the northbound stop. There is also a bike parking cage for Bike and Ride customers.

Figure 6 ACTION Weekday Bus Service

Bicycles and Pedestrians

On road cycle lanes and a shared use path are provided on Melrose Drive. Foot paths are provided on both Theodore Street and Melrose Drive as shown in Figure 3 below. There is also a Bike and Ride bicycle cage adjacent to the City-bound bus stop.


D R A F T


15

Figure 7 ACT Walking and Cycling Map: Melrose Drive / Theodore Street detail

Legend: On road Cycle Lane, Shared Path, Foot path

Land Use

There is no direct property access on Melrose Drive. Theodore Street provides direct access to residential properties.

3.4 Site inspection A weekday site inspection was undertaken on Tuesday, 3 July 2012 at 10:30 AM. The following observations were noted:

- The majority of turning movements at the intersection are right turn movements out of Theodore Street to Melrose Drive.

- Many cars turning right on Melrose Drive quickly moved left to turn left at Launceston Street.

- The intersection warning sign for pedestrians and bicycle riders (on side road) on Melrose Drive when turning into Theodore Street is confusing and can be misunderstood.

- Sight distance is adequate at the intersection.

- A waiting queue on the right turn movement out of Theodore Street was observed.

- There was little to no queuing on the left turn movement out of Theodore Street.

- Drivers turning right into and out of Theodore Street may misjudge the gap crossing three lanes which are travelling at 70 km/h.

- It was also noted that there was no formal pedestrian crossing on Melrose Drive.


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16

Queuing on the right turn movement out of Theodore Street onto Melrose Drive.

No formal pedestrian facilities for crossing Melrose Drive at Theodore Street

Intersection ‘On side road’ warning sign for pedestrians and bicycle riders may be misunderstood.

The left turn out of Theodore Street was not very heavy at 10:30 am.

3.5 Remedial measures Several scenarios were considered at this location. The greatest crash reduction would probably come from installing traffic signals at this intersection, however this would be outside the scope of low cost safety measures, so were not investigated any further. Banning the right turn out of Theodore Street, particularly in the morning, would reduce the likelihood of crashes; however, this would have to be studied separately as it would impact other intersections within the network. A third scheme was considered, which involved extending the bus lane through the intersection at Theodore Street. This would require merging the left and centre lanes of Melrose Drive south of the bus stop, and may impact the intersection of Melrose Drive and Launceston Street. This was dismissed due to the potential capacity reduction and unintended safety impacts at the intersection and merge point.

The proposed remedial measure for this intersection is enhancing intersection conspicuity with dual intersection warning signs on Melrose Drive, and marking the intersection on northbound Melrose Drive with a ‘Keep Clear’ box. The intersection warning signs will remind drivers that turn movements may be occurring ahead. One sign is mounted in the median as the road is quite wide here, and warnings in the verge may be missed or obscured by vehicles in the bus stop. The keep clear marking will give drivers turning out of Theodore Street a wider field of vision to check for oncoming traffic.


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17

Figure 8 Low-Cost Safety Option for Melrose Drive / Theodore Street


3.6 Expected crash reductions Expected crash reductions were tabulated by applying reductions available from road safety literature to the 5-year crash experience in the intersection. Where crash reductions were not available through research, engineering judgement and experience were used to determine potential benefits. Only crashes of the particular type identified through literature or by engineering judgment, and on the correct approach to be affected by the option, were considered targeted crashes for reduction. The results are detailed in the “Target Crashes” and “Assumed Reduction” columns in Table 7.

The low cost safety improvement option, intersection warning signs and keep clear marking, should reduce adjacent approach (codes 101-109) and opposing turn crashes (codes 202-206) by 5%. This treatment should reduce 23 of 37 total crashes that occurred during the crash history period.

3.7 Economic analysis Crash costs for 2011 were obtained from Roads ACT to develop an economic analysis of the costs and benefits of low cost improvements. Crash costs by crash type were used for costing future crashes. When crash types were encountered that did not have indicative costs; the cost of an average property damage crash was substituted in the analysis.



D R A F T


18

Table 7 Benefit/cost analysis Melrose Drive / Theodore Street

LOCATION: Melrose Drive / Theodore Street OPTION 1

Discount rate 7% Intersection warning signs and a keep clear box.




l C

rash

es

Cos

t per

C

rash

Cos

t of

Cra

shes

Targ

et

Cra

shes

Ass

umed

R

educ

tion

Dis

coun

ted

Ben

efits


201 Head-on 138,301

202-206 Opposing vehicles; turning 3 32,584 97,752 3 5% $6,866

301 - 304 Rear-end 8 19,909 159,272

305 - 307 Lane change 3 21,557 64,671





501 - 506 Overtaking 28,113


Other 1 18,096 18,096

TOTAL 37 $1,115,621 23 $56,403

B/C


Costs

2.78 $36,135 $20,268


D R A F T


19

The benefit to cost analysis indicates that the proposed low cost safety improvement has a Benefit/Cost Ratio of 2.78. This indicates the treatment would result in over two and half times the cost of improvements returned in crash benefits.

3.8 Recommendation The proposal for Intersection warning signs and a ‘keep clear’ is recommended on Melrose Drive as a form of low cost improvement.

However, it should be noted that higher safety improvement could be gained with more capital expenditure (e.g.: signalising the intersection) although investigation into this type of treatment was not explored in this study.


D R A F T


20

4.0 Wentworth Avenue / Mildura Street / Leichhardt Street

4.1 Background Safety improvements were made in 2007 under the black spot program to the intersection of Wentworth Avenue, Mildura Street and Leichhardt Street. The improvements included installation of traffic islands, signs and line marking. An assessment of the improvements was conducted by Roads ACT in 2010. The crash data for both the “before treatment’ and ‘after treatment’ crashes were compared. Table 8 Crash comparison before and after treatment Wentworth Avenue / Mildura Street / Leichhardt Street

RUM Code

ACT Crash Type

Before (1/03/04 – 28/02/07)

After (1/10/07 – 30/09/10) Change

% Fatal Injury PDO Total Fatal Injury PDO Total

001-003

101-109 1, 2 5 6 11 1 7 8 -27.3

201 5

202-206 1 1 1 100.0

301-304 6 1 1 1 1 0

305-309 3, 9 1 1 100.0

401-408 8 2 2 200.0

501-506 9

601-609

701-709 19

901

Totals 5 7 12 1 12 13 8.3

Table 8 outlines increase and decrease in crashes before and after the treatment specific to the crash type and severity for each crash group.

The most dominant crash type before the treatment was due to collisions between vehicles from adjacent approaches (RUM 101-109). After black spot improvements, the total number of these crashes was reduced by 27%. However, there was one fatal adjacent approach crash in the after study period. Opposing turn collisions (RUM 202-206), lane side swipes (RUM 305-309) and manoeuvring crashes (RUM 401-408) all increased. An overall 8% increase in the total number of crashes was detected at this intersection after the treatment.

The modifications done to this intersection was not found to be cost effective as it had increased the number of crashes by 8% and given a savings of only $ 1,596 in crash costs per annum.

4.2 Crash analysis The recorded crashes were obtained from Roads ACT for the five year period from January 2007 through December 2011. These crashes were reviewed to identify any crash patterns and trends and also assist in the understanding of the contributory causes of the crashes.

The records indicate that 16 crashes have occurred at the intersection of Melrose Drive and Theodore Street. Of these crashes, 1 was a fatal crash and the rest were property damage only crashes as shown in Table 9.


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21

Table 9 Updated crash history Wentworth Avenue / Mildura Street / Leichhardt Street

Severity 2007 2008 2009 2010 2011 Total

Fatal 1 1




3 4 5 1 2 15

Total 3 5 5 1 2 16

In 2011, 2 crashes were reported at the intersection. This crash frequency represents a significant decrease from the 3.5 per annum crash rate of the previously studied 2007 – 2010 period.

Crashes were well distributed among types; however, 9 of 16 were right angle crashes from adjacent approaches. A crash factor matrix has been prepared and is shown in Table 10.


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22

Table 10 Crash factor matrix Wentworth Avenue / Mildura Street / Leichhardt Street

DCA Code On Street Key Direction

Year of Crash

Total

Other Direction Surface Light Conditions Type of Day

Weekday Peak

Period

2007

2008

2009

2010

2011

Nor

th

Eas

t

Sou

th

Wes

t

Dry

Wet

Day

Dar

k

Publ

ic H

olid

ay

Wee

k - e

nds

Wee

k - d

ays

101 Wentworth Av. SB 2 2 2 2 2 1 1

Mildura St. SB 1 1 2 4 1 2 3 4 3 1 4 1

102 Wentworth Av. WB 1 1 2 1 1 2 1 1 1

Mildura St. WB 1 1 1 1 1

104

Wentworth Av. SB 1 1 1 1 1 1

Mildura St. SB 1 1 1 1 1 1

202 Wentworth Av. NB 1 1 1 1 1 1

301 Wentworth Av. NB 1 1 1 1

308

Wentworth Av. NB 1 1 1 1 1

404 Mildura St. NB 1 1 2 1 2 2 2

Total 3 5 5 1 2 16 3 2 2 8 14 2 11 1 4 11 3


D R A F T


23

4.3 Traffic characteristics Intersection/Road Geometry

Figure 9 ACTMAPi aerial view of Wentworth Avenue / Mildura Street / Leichhardt Street

Wentworth Avenue

Wentworth Avenue is an arterial road running northwest -southeast across Kingston suburb of the ACT. It is a 4 lane divided carriage way separated by a 32 m median at its intersection with Leichhardt Street/ Mildura Street. The pavement width at its intersection with Leichhardt Street is about 9 metres in the northbound direction and 5.5 metres in the southbound direction.

Leichhardt Street

Leichhardt Street is a major collector road in the suburbs of Kingston and Griffith connecting Wentworth Avenue to Giles Street. It is a two lane undivided road. At its intersection with Wentworth Avenue the pavement width is about 8 metres.

Mildura Street

Mildura Street is a major collector road in the suburb of Fyshwick connecting Wentworth Avenue to Canberra Avenue. It is a two way undivided road. At its intersection with Wentworth Avenue the pavement width is about 11.4 metres.


The ACT Traffic Volumes 2005 – 2007 report indicates that in August, 2007, the segment of Wentworth Avenue between Hely Street and Hume Circle (one block east of the intersection) carried approximately 20,000 vehicles on each weekday; with about 1,300 travelling toward the subject intersection in the AM peak hour, and 1,100 travelling away from the intersection in the PM peak hour.


D R A F T


24

The sign-posted speed limits on the roads approaching the intersection are as follows:

60 km/h on Wentworth Avenue

50 km/h on Mildura Street

50 km/h on Leichhardt Street

Public transport

Wentworth Avenue carries the Red Rapid 200 service and several Xpresso services. Mildura Street carries route 80 weekday service and 980 weekend service; however current routing does not go through the intersection. There are no bus stops located near the intersection.



On road cycle lanes and a shared use path are provided on Wentworth Avenue. Foot paths are provided on both Leichhardt Street and Mildura as shown in Figure 11 below.


D R A F T


25

Figure 11 ACT Walking and Cycling Map: Wentworth Avenue detail

Legend: On road cycle lane, shared path, foot path

Land Use

There is no direct property access on Wentworth Avenue. Leichhardt Street and Mildura Street provide direct access to commercial properties, including the railway station and the Capitol Chilled Foods facility.

4.4 Site inspection A weekday site inspection was undertaken on Tuesday, 10 July 2012 at 2:30 pm. The following observations were noted:

The intersection can be difficult to perceive when coming from the west on Wentworth Avenue.

Give Way signs at the intersection can be replaced with Stop signs in order to improve intersection crossing and reinforce priority.

The One Way sign post that was seemingly located at the intersection of Wentworth Avenue/ Mildura Street was uprooted which left a hole on the side of the road by the pedestrian shared path.

Motorists may be confused about priority when through and turning vehicles leaving the median conflict with through and turning vehicles leaving the side roads.

The bicycle warning sign on Mildura Street approaching Wentworth Avenue is may not be perceived properly by some drivers.


D R A F T


26

Uprooted One Way sign post by the side of the road

Unclear bicycle warning sign on Mildura Street. One Give Way sign on the Mildura Street east approach

4.5 Remedial measures Converting the median Give Way signs to Stop signs was considered because drivers may have difficulty looking to their left when leaving the median. However the sight lines at the intersection appear to be adequate, and the Australian Standard AS 1742.2 explicitly discourages installation of Stop signs solely due to crash history.

The recommended low cost safety improvements at the intersection of Wentworth Avenue, Mildura Street and Leichhardt Street include:

- Reposition existing Give Way sign on Mildura Street closer to intersection

- Supply additional Give Way sign on the median island on Mildura Street

- Refresh paint and install Reflective Pavement Markers (RPM) for all median crosshatching in intersection (see Figure 12).


D R A F T


27

Figure 12 Low Cost Safety Improvements Wentworth Avenue / Mildura Street / Leichhardt Street



The low cost safety improvement option, intersection warning signs and keep clear marking, should reduce adjacent approach (codes 101-109) by 5%. This treatment should reduce the likelihood of 11 of 16 total crashes that occurred during the crash history period.

4.7 Economic analysis Crash costs for 2011 were obtained from Roads ACT to develop an economic analysis of the costs and benefits of low cost improvements. Crash costs by crash type were used for costing future crashes. When crash types were encountered that did not have indicative costs; the cost of an average property damage crash was substituted in the analysis.



D R A F T


28

Table 11 Benefit/cost analysis Wentworth Avenue / Mildura Street / Leichhardt Street

LOCATION: Wentworth Ave / Mildura St / Leichhardt St OPTION

Discount rate 7% Restripe Mildura Island, reposition Give Way signs, RPMs in median




l C

rash

es

Cos

t per

C

rash

Cos

t of

Cra

shes

Targ

et

Cra

shes

Ass

umed

R

educ

tion

Dis

coun

ted

Ben

efits


201 Head-on 138,301 0

202-206 Opposing vehicles; turning 1 32,584 32,584

301 - 304 Rear-end 1 19,909 19,909

305 - 307 Lane change 21,557 0

001 - 003 Vehicle hits pedestrian 163,946 0

706 - 707 Loss of Control (L or R turns) 82,427 0

401 - 402 Hit parked vehicle 21,586 0

601 Hit parked vehicle 23,675 0

501 - 506 Overtaking 28,113 0

901 Fell from moving vehicle 70,222 0

Other 3 18,096 54,288

TOTAL 16 $484,696 11 $27,246

B/C


Costs

1.34 $6,978 $20,268


D R A F T


29

The benefit to cost analysis indicates that the proposed low cost safety improvement has a Benefit/Cost Ratio of 1.34. This indicates the treatment would result in a crash reduction value only slightly greater than installation and maintenance costs.

4.8 Existing deficiencies and maintenance items The uprooted One Way sign at the northeast corner should be reinstalled.

4.9 Recommendation Despite not meeting the desired ratio of benefits outweighing costs by a factor of two, the low cost safety improvements at Wentworth Avenue and Mildura Street / Leichhardt Street may still be considered for their ability to improve safety at the intersection. If the restriping of the approach islands and raised pavement markers are not initially installed, replacement of a second Give Way sign on the median of Mildura Street should be considered as a maintenance item.

Should the crash record continue to increase in the future, consideration should be given to a more substantial upgrade to the intersection.


D R A F T


30

5.0 Kuringa Drive

5.1 Background Safety improvements were made under the black spot program to the mid-block section of Kuringa Drive between Tillyard Drive and Kingsford Smith Drive in June 2008. These improvements included Installation of warning signs, guardrails and lighting. An assessment of the improvements was conducted by Roads ACT in 2011. The crash data for both the “before treatment’ and ‘after treatment’ crashes were compared. Table 12 Crash comparison before and after treatment Kuringa Drive

RUM Code

Before (1/03/05 – 28/02/08)

After (1/10/08 – 30/09/11) Change

%

Fatal Injury PDO Total Fatal Injury PDO Total

001-003 101-109 201 202-206 301-304 2 2 -100.0 305-309 1 1 +100.0 401-408 501-506 601-609 1 1 1 1 0 701-709 1 8 9 1 2 3 -66.7 801-805 4 4 1 7 11 19 +375.0 Totals 1 15 16 1 8 15 24 +50.0

Table 12 outlines the increase and decrease in crashes before and after the treatment specific to the crash type and severity for each crash group.

Prior to treatment, the most frequent crash type was single vehicle off path on straight (RUM 701-709). This fell by 66.7% after the application of treatment, and off path on curve (RUM 801-805) crashes increased by 375%. A total increase of 50% in the number of crashes was detected on this midblock section.

It was considered that continued speeding on the road may have been responsible for the continued crashes.

5.2 Updated crash analysis The recorded crashes were obtained from Roads ACT for the five year period from January 2007 through December 2011. The four years since safety treatments were installed (2009 – 2011) were analysed. The records indicate that 23 crashes occurred on Kuringa Drive in this period. These crashes include one fatality, 8 injury crashes, and 14 property damage crashes as shown in Table 13.


D R A F T


31

Table 13 Updated crash history Kuringa Drive

Severity 2009 2010 2011 Total

Fatal 1 1


2 1 3


1 4 5


4 6 4 14

Total 6 12 5 23

The crash frequency is almost 8 crashes per year. An increase over the five crashes per year in the period studied before the treatment was installed. This period contained nine injury or fatal crashes compared to one injury crash in the previous analysis period.

The most common crash types were single vehicles leaving the roadway. Nineteen of 23 (85%), were RUM Code 8xx, “off path on curve” crashes. Two more were code 7xx, “off path on straight”. The bulk of the crashes, 20 of 23, occurred in the westbound direction. Twelve of 23 crashes were on wet roads, and one involved snow or ice. Only one crash occurred during the weekday peak traffic periods. Fourteen (61%) occurred on a weekend or public holiday. A crash factor matrix is shown in Table 14.


D R A F T


32

Table 14 Crash factor matrix for Kuringa Drive

DCA Code On Street

Key Direct-ion

Year of Crash

Total Surface

Light Conditio

ns Type of Day

Weekday Peak

Period

2009

2010

2011

Dry

Wet

*

Day

Dar

k P

ublic

H

olid

ay

Wee

k - e

nds

Wee

k - d

ays

307

Kuringa Drive WB 1 1 1 1 1

609


703


704


801

Kuringa Drive WB 2 2 2 1 1 2

Kuringa Drive EB 1 1 2 1 1 1 1 1 1

802

Kuringa Drive WB 1 2 3 3 2 1 1 1 1

803

Kuringa Drive WB 2 2 2 1 1 1 1

Kuringa Drive EB 1 1 1 1 1

804


805


Total 6 12 5 23 10 13 14 9 3 11 9 1


D R A F T


33

5.3 Traffic characteristics Road geometry

Kuringa Drive is a two lane arterial road connecting the north Belconnen suburbs of Fraser and Spence to the Barton Highway. With the extension of Clarrie Hermes Dive, Kuringa Drive also provides access to Nicholls and Ngunnawal in Gungahlin.

The pavement width is about 6.4 metres widening slightly at curves. There are three curved sections: a very sharp curve at Tillyard Drive, back to back curves about midway to Kingsford Smith Drive, and a curve just west of Kingsford Smith Drive. The curves are posted with advisory speed warning signs at 35, 45 and 55 km/h.

Figure 13 Kuringa Drive

Source: Google Earth Pro

Kuringa Drive


D R A F T


34

Figure 14 Kuringa Drive / Tillyard Drive Curve

Source: ACTMAPi

Figure 15 Kuringa Drive back-to-back curves

Source: ACTMAPi


D R A F T


35

Figure 16 Kuringa Drive / Kingsford Smith Drive

Source: ACTMAPi

Land use

There is no residential frontage along the road. The only property access on the road is a driveway approximately 400 m west of Kingsford Smith Drive which provides access (through a locked gate) to the rural blocks to the north.


The ACT Traffic Volumes 2005 – 2007 report indicates that in 2007, Kuringa Drive between Barton Highway and Owen Dixon Drive was travelled by approximately 11,000 vehicles each weekday. This gives an indication of the volume of traffic in the study area. Traffic volumes may have risen in recent years with development in northern and western Belconnen. Volumes will likely rise again with the recent opening of the Clarrie Hermes Drive extension at the signalise intersection of Barton Highway and Kuringa Drive.

The sign-posted speed limits on Kuringa Drive are as follows:

- 80 km/h from Barton Highway to Owen Dixon Drive - 70 km/h from Owen Dixon to Kingsford Smith Drive - 60km/h from Kingsford Smith Drive to Tillyard Drive

Public transport

There are no ACTION bus services on Kuringa Drive. Weekday bus services stop nearby on Tillyard Drive (314) and Kingsford Smith Drive (315). There are similar weekend and Xpresso (peak hour) services. The weekday bus services are depicted in Figure 17.


D R A F T


36



There are no bicycle or pedestrian facilities on this section of Kuringa Drive. Nearby foot paths and shared paths are depicted in Figure 18.

Figure 18 ACT Walking and Cycling Map: Kuringa Drive detail

Legend: On road Cycle Lane, Shared Path, Foot path


D R A F T


37

5.4 Site inspection A weekday site inspection was undertaken on Monday, 15 October 2012 at 2:00 PM. The following observations were noted:

- The road presents a long (1.5 kilometres) stretch of asphalt without intersections or turn offs

- Pavement width appears adequate, however, there are no paved shoulders, and soft shoulders are often overgrown or in poor condition

- There is little superelevation through curves

- Several signs are missing, and many are overgrown

- Asphalt condition is adequate, markings are clear and raised pavement markers are plentiful

- Several guide posts are missing or damaged

- “Reduce Speed Now” signs are conspicuous, however some are obscured by trees

- Curve warning and advisor speed signs are standard size and mounting

- In the middle of the afternoon, traffic was steady in both directions, and vehicles were not platooned Drivers travelled the road at differing speeds. Some were very cautious and adhered to speed limits and advisory speeds, others exceeded speed limits

- Vehicle skid marks were noted on the westbound lane, possibly indicating an eastbound driver who lost control and crossed the oncoming lane before leaving the roadway

Shoulder erosion westbound in back-to-back curves Unmarked and unprotected culvert headwall westbound

Overgrown signage Damaged guide post


D R A F T


38

Reduce speed sign and curve warning sign westbound Damaged speed limit sign eastound near Tillyard Drive

Overgrown curve warning sign eastbound

Missing curve warning sign eastbound “Reduce Speed Now” sign obscurred


D R A F T


39

5.5 Remedial measures The proposed remedial measures for this midblock road section are:

- Improve speed limit signage with larger signs at the beginning of the road segment and repeater signs along the road. To highlight the change in speed limit on the approach form the west, the speed limit should be marked in the westbound lane after Kingsford Smith Drive.

- Enhance curve warning and advisory speed signs by installing on both sides of the road leading into the back to back curve and repeating curve warning signs on both sides of the road in between back to back curves. The missing curve warning sign eastbound should be replaced.

- Increase supply of retro-reflective raised pavement markers (RRPMs) by halving spacing along the centreline and edge lines approaching and through all signposted curves.

Figure 19 Tillyard Street curve detail for RRPM treatment extents

Figure 20 Back to back curve detail for RRPM treatment extents


D R A F T


40

Figure 21 Kingsford Smith Drive curve detail for RRPM treatment extents

Figure 22 Enhanced speed limit marking on Kuringa Drive


D R A F T


41

Figure 23 Enhanced curve warning and speed signs on Kuringa Drive


D R A F T


42



The low cost safety improvement options—enhanced speed limit signs and marking, curve warning signs and retro-reflective raised pavement markers—should reduce “Other” crashes by 10%. Other crashes include primarily RUM code 703 – 704 off path on straight and 801 – 805 off path on curve crashes. This treatment should reduce the likelihood of 22 of 23 total crashes that occurred during the crash history period.

5.7 Economic analysis Crash costs for 2011 were obtained from Roads ACT to develop an economic analysis of the costs and benefits of low cost improvements. Crash costs by crash type were used for costing future crashes. When crash types were encountered that did not have indicative costs; the cost of an average property damage crash was substituted in the analysis. It should be noted that crash costs were not provided for “Other” crashes such as off path on straight and off path on curve. Following methodology employed in previous safety and black spot studies, the cost of a property damage crash was substituted for these values. However, actual crash costs may be greater than this aggregate value. This may cause the benefit cost analysis to understate the benefits of a given treatment.


.


D R A F T


43

Table 15 Benefit/cost analysis Kuringa Drive

LOCATION: Kuringa Drive (Tillyard Street to Kingsford Smith Drive LOW COST OPTION

Discount rate 7% Enhanced speed limit signs and marking, curve warning signs and RRPMs




l C

rash

es

Cos

t per

C

rash

Cos

t of

Cra

shes

Targ

et

Cra

shes

Ass

umed

R

educ

tion

Dis

coun

ted

Ben

efits

101-109 Intersection, adjacent approaches $35,265

201 Head-on 138,301

202-206 Opposing vehicles; turning 32,584

301 - 304 Rear-end 1 19,909 19,909

305 - 307 Lane change 21,557





501 - 506 Overtaking 28,113


Other 22 18,096 398,112 22 10% $93,206

TOTAL 23 $418,021 $418,021 22 $93,206

B/C


Costs

4.60 $72,938 $20,268


D R A F T


44

The benefit to cost analysis indicates that the proposed low cost safety improvement has a Benefit/Cost Ratio of 4.60. This indicates the treatment would result in a crash reduction value four times greater than installation and maintenance costs.

5.8 Existing deficiencies and maintenance items Overgrown trees, particularly those obscuring warning signs should be cut back. Missing and damaged signs should be replaced. The eroded shoulder in the westbound lane in the back to back curves should be repaired. Guide posts in the verge and marking hazards should be reviewed and repaired throughout the road length and particularly in the back to back curves.

5.9 Recommendation The proposal for enhanced speed limit signs and marking, curve warning signs and retro-reflective raised pavement markers is recommended for the mid-block section of Kuringa Drive between Tillyard Street and Kingsford Smith Drive as a form of low cost improvement. However, it should be noted that higher safety improvement could be gained with more capital expenditure (e.g. realignment) although investigation into this type of treatment was not explored in this study.

The existing deficiencies identified in Section 5.8 should be addressed as part of regular maintenance.

It should be noted that this form of treatment relies on a high level of driver compliance. As such, this location should be considered for increased speed enforcement. Extra attention should be given in the back to back curves. This enforcement should be focused on the westbound traffic, particularly on straight segments and in the back to back turns. Both police speed enforcement and automated speed enforcement means should be considered.

low cost safety improvements hindmarsh drive, melrose drive, wentworth avenue & kuringa drive

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