Scottish Trunk Road Infrastructure Project Evaluation - Evaluation Report for Trunk Road Projects Opened between April 09 and March 10
Appendix A: Evaluations For Projects That Opened Between April 09and March 10
A.1 A830(T) ARISAIG TO LOCH NAN UAMH
A.1.1 Introduction
Project Overview
The project involved the upgrade of 7.5 kilometres of single track road with passing places on the A830(T) between Arisaig and Loch Nan Uamh to single carriageway, to allow for the two way flow of traffic on this link to Mallaig and its ferry connections to the Small Isles.
The general location of the project is shown in Figure A.1a.
The A830(T) Arisaig to Loch Nan Uamh project was officially opened to traffic on 15th April 2009.
Project Objectives
The objectives of the A830(T) Arisaig to Loch Nan Uamh project were set as follows:
- to minimise the impact of the route upgrading on the sensitive environment of the area, in particular, the designated sites, Glen Beasdale candidate Special Area of Conservation, Morar, Moidart and Ardnamurchan National Scenic Area, Proposed Area of Great Landscape Value, the Designed Landscapes of Larachmore Gardens and Arisaig House, other cultural heritage interests, the rural community and existing land use;
- to improve road safety, reducing the number of damage, slight only and serious accidents, on this section of the A830;
- to provide a value for money solution to improve journey times and level of service for local, business, commercial and tourist users of the A830, maintaining the lifeline link to Arisaig, Morar, Mallaig and to the ferry links to the Small Isles: Rum, Muck, Eigg, Canna and to South Uist and Skye;
- to aid sustainable economic development, encourage inward investment and creation of business opportunities in the Ardnamurchan and Moidart areas;
- to maintain a link to the Beasdale Railway Halt and Highland Line;
- to fit with land-use policy as identified in Highland Council Structure Plan and Lochaber Local Plan;
- to ensure rural and island communities remain sustainable and strengthen in the longer term, providing improvement in links to employment and for tourism;
- to provide better local community access, aid more efficient delivery of services and improve communications locally;
- to enable the area at a regional level to realise its economic development potential in terms of external markets, in particular, tourism, timber and fishing;
- to improve access to Arisaig, Morar, Mallaig, the Small Isles, South Uist and Skye for non motorised users of the trunk road corridor, in particular touring cyclists and walkers; and
- to ensure a good fit with existing access to established Rights of Way and minor roads and tracks used by walkers in the area between Glen Beasdale and Arisaig.
Evaluation Methodology
The A830(T) Arisaig to Loch Nan Uamh project has been evaluated against the above objectives and the following criteria:
- Environment;
- Safety;
- Economy;
- Integration;
- Accessibility & Social Inclusion;
- Costs to Government; and
- Value for Money.
The evaluation is supported by the consideration of network traffic indicators, including traffic volumes and travel times presented in the following section.
Traffic Volumes
The location of the Automatic Traffic Counter (ATC) within the study area is shown in Figure A.1a.
Comparison Between Pre and Post Opening Traffic Flows
The Annual Average Daily Traffic (AADT) flows pre and post project opening on the A830(T) route within the vicinity of the project are presented in Table A.1.1.
|
ATC Reference |
AADT by Year |
|||||
|---|---|---|---|---|---|---|
|
2006 |
2007 |
2008 |
2009 |
2010 |
2011 |
|
|
A830(T) West of Polnish |
||||||
|
ATC01072 |
931 |
1,002 |
1,032 |
Year of Opening |
1,024 |
1,006 |
A comparison between pre and post opening traffic volumes on the A830(T) mainline to the west of Polnish indicates that traffic flows in 2010 were broadly comparable with 2008 flow levels and flows in 2011 were marginally lower.
Given the nature of the A830(T) Arisaig to Loch Nan Uamh project, reductions in traffic are not likely to be as a consequence of changes to the carriageway standard and may be as a result of general reductions in traffic volumes across the wider trunk road network due to the economic downturn experienced during the evaluation period.
Comparison Between Predicted and Actual Traffic Flows
The opening year flow comparisons for the A830(T) Arisaig to Loch Nan Uamh project are based on AADT flows from 2010 as this was the first full year of reliable traffic data available from Transport Scotland's traffic counter within the vicinity of the project.
As part of the project's appraisal, National Road Traffic Forecasts (NRTF) high traffic growth factors were applied to the 2005 base year traffic flows to derive opening and future modelled assessment year traffic flows. Predicted traffic flows for 2010 have been derived by factoring the 2005 base year flows used in the economic assessment with NRTF high traffic growth factors.
A summary of the actual and predicted traffic data is shown in Table A.1.2 below.
* 2010 flows (first full year of ATC data available)
The comparison between predicted and actual AADT flows in Table A.1.2 indicates that the predicted 2010 flow was 3.4% (around 30 vehicles) greater than the observed 2010 flow, which is well within accepted limits.
Carriageway Standard Assessment
A single carriageway was constructed on the A830(T), between Arisaig and Loch Nan Uamh, to allow for the two way flow of traffic on this link to Mallaig and its ferry connections to the Small Isles to help improve journey times and level of service as well as aid sustainable economic development.
An assessment of the carriageway standard according to TA 46/97- Economic Assessment and Recommended Flow Ranges for New Rural Road Links, which applied at the time of the project design, is shown in Table A.1.3 based on the observed 2010 traffic flow.
|
Opening Year AADT* |
TA 46/97 Standard |
Constructed Standard |
|---|---|---|
|
1,024 |
Single 2-Lane |
Single 2-Lane |
* 2010 flows (first full year of ATC data available)
The carriageway assessment indicates that the observed 2010 flow lies within the flow range appropriate for a single 2-lane standard of carriageway, which is the minimum standard.
Travel Times
Comparison Between Pre and Post Opening Travel Times
Journey time surveys were carried out for the A830(T) Arisaig to Loch Nan Uamh project in September 2002 and April 2012, to provide an indication of the changes in average journey times along the A830(T) between Arisaig and Loch Nan Uamh.
The average pre and post journey times along with the post opening savings in travel time are shown in Table A.1.4 below.
Stakeholder Feedback
Anecdotal evidence indicates that the reliability of journey times has improved as a result of the project.
Shiel Buses, a local bus operator, was approached to determine the impact of the project on local bus operations. The company, which runs several services along the A830(T) route, indicated that, as a result of the project, a more reliable timetable and service could be provided and arrival times to connect with the Acharacle to Fort William connection could now be accurately predicted.
Comparison Between Predicted and Actual Travel Times
The available predicted 2010 journey times have been compared with the post opening journey times collected in April 2012. The comparison between the available predicted and actual journey times indicates that the predicted journey times on the A830(T) between Arisaig and Loch Nan Uamh are around 1 minute longer than the observed journey times in both directions of travel.
A.1.3 Environment
Review of Environmental Mitigation Measures
The environmental mitigation measures originally proposed for the A830(T) Arisaig to Loch Nan Uamh project were obtained from the project's Environmental Statement. A review of the environmental mitigation measures was carried out in July 2011, which confirmed that the majority of measures committed within the Environmental Statement were in place and were providing appropriate levels of mitigation. The key mitigation measures implemented as part of the project are as follows:
- provision of culverts and water course realignment to protect existing riverbeds;
- encouragement of the regeneration of natural oakwood habitat;
- specific measures for the protection of mammals including badgers and otters;
- construction of pedestrian and estate access and stone walling on the edge of Arisaig Village;
- construction of deer fencing to minimise collisions between larger mammals and vehicles;
- new structures constructed with a similar design to existing structures to maintain landscape character;
- provision of deciduous woodland planting, native grasses and herbs to grub up sections of the redundant road;
- provision of deciduous woodland planting on embankment slopes to reduce visual impacts from Arisaig House, Borrodale House and Farm Steading;
- provision of a dedicated cycle / pedestrian track linking to Arisaig village; and
- provision of a road with sufficient capacity to ensure the free flow of traffic along the route to avoid driver frustration.
Noise and Air Quality
Given the rural nature of the A830(T) Arisaig to Loch Nan Uamh project, no significant impact on noise and air quality is expected. It is therefore not appropriate to evaluate the project's impact on noise and air quality.
Environment: Key Findings
The review of mitigation measures implemented for the A830(T) Arisaig to Loch Nan Uamh project confirmed that the majority of measures committed within the Environmental Statement were in place. Whilst some variations from the proposed mitigation measures had been identified, these were not considered to have had a material detrimental impact on the general integration of the project into its surrounding.
A.1.4 Safety
Accidents
Comparison Between Pre and Post Opening Personal Injury Accident Numbers
The locations and severities of accidents occurring within the vicinity of the A830(T) Arisaig to Loch Nan Uamh project 3 years before and 1 year after project completion are shown in Figures A.1b and A.1c.
A summary of the personal injury accident data is shown in Table A.1.5.
|
Period |
Fatal |
Serious |
Slight |
Total Accidents |
|---|---|---|---|---|
|
3 Years Before |
||||
|
A830(T) |
0 |
0 |
4 |
4 |
|
1 Year After |
||||
|
A830(T) |
0 |
0 |
0 |
0 |
As can be seen from Table A.1.5, no personal injury accidents occurred in the 1 year period following the opening of the project in comparison to four personal injury accidents (slight) in the 3 years before opening, suggesting a potential improvement in road safety.
Stakeholder Feedback
HITRANS (Highlands and Islands Transport Partnership) questioned whether the improved standard of carriageway may have created a perception for drivers that vulnerable users will be segregated and, as such, drivers may be less aware of active travel users on adjacent sections of the A830(T) route. The pedestrian / cycle track was observed as being in regular use during the environmental mitigation measures review and there is no evidence of a reduction in safety for active travel users on adjacent sections.
In addition, anecdotal feedback from The Highland Council suggests that there has been an improvement in safety for cyclists using the "old" road to access Arisaig, which has seen reduced traffic levels as a result of the project.
Road Safety Audits
The Stage 4 Road Safety Audit (RSA) was carried out in June 2010 and examines the accidents which occurred during the period January 2005 to May 2010. This period differs with the summary of pre and post opening accidents presented in Table A.1.5, which covers the 3 year period prior to the opening of the project from 15th April 2006 to 14th April 2009 and the 1 year period following opening of the project from 15th April 2009 to 14th April 2010.
The RSA notes that five slight injury and 14 non-injury accidents occurred between January 2005 and the opening of the project and confirmed that no accidents (injury or damage only) had occurred within the vicinity of the project in the 1 year period after project opening. One of the accidents that occurred prior to the opening of the project involved a collision between a car and a parked HGV and the RSA suggests that this accident may have been attributable to the construction traffic associated with the A830(T) improvements.
The Stage 4 RSA raised some issues that still require to be resolved. These focus on incorrect mounting of 'Give Way' signs; and the requirement for fencing to protect cyclists and pedestrians from leaving the cycleway on a steep, downhill section of the combined cycle/footway. Furthermore, the audit concluded that on the eastbound approach to Loch Nan Uamh, cyclists are more likely to remain on the carriageway than use the segregated section as certain features of this section are not attractive to users (the eastbound cycle facility may result in cyclists travelling downhill at speed).
Safety: Key Findings
An assessment of the 1 year post opening personal injury accidents and a review of the Stage 4 RSA report, suggests that the A830(T) Arisaig to Loch Nan Uamh project is operating safely, however, some unresolved issues have been raised pertaining to active travel users.
Transport Economic Efficiency
The comparisons between predicted and actual traffic flows and travel times, presented in section A.1.2, can be considered a proxy for whether the predicted economic benefits of the project are likely to be realised.
Comparison Between Predicted and Actual Traffic Flows
The comparison between predicted and actual traffic flows indicates that the predicted 2010 flow was within 3.4% (around 30 vehicles) of the observed 2010 flow on the A830(T).
Comparison Between Predicted and Actual Travel Times
The comparison of predicted and actual travel times indicates that the predicted journey times are around 1 minute longer than observed journey times.
Stakeholder Feedback
Highlands and Islands Enterprise, the local enterprise body for the region, has suggested that the project has had a positive impact on several aspects of local economic development including a marked improvement in: journey times and journey time reliability; the attraction of visitors to the area; the connectivity of Mallaig and Arisaig to Fort William; and a perceived improvement to access for local businesses.
Economy: Key Findings
The comparison of predicted and actual traffic flows and travel times confirms that the predicted economic benefits may have been underestimated.
Qualitative anecdotal evidence indicates that the project has provided local economic benefits - reducing time lost to commuters, businesses, transport operators and visitors through improved journey time reliability; improving the attractiveness of the area for investment; and improving economic ties between Mallaig and Fort William.
A.1.6 Integration
Transport Integration
Stakeholder Feedback
Shiel Buses, a local bus operator on the route, indicated that as a result of the project, it had been able to provide a more reliable timetable and service and is now able to predict arrival times to link with the Acharacle to Fort William connection.
Highlands and Islands Enterprise has suggested that the project has played a role in encouraging use of the Mallaig to Armadale ferry route. Whilst the total number of passengers using the Mallaig to Armadale ferry service has increased from 209,000 in 2009 to 221,000 in 2011 (Ref. Annual Carrying Statistics, CalMac Ferries Ltd), it cannot be confirmed that the A830(T) Arisaig to Loch Nan Uamh project has been the sole factor. Transport Scotland's Scottish Ferry Services: Draft Plan for Consultation (2011) states that the Mallaig to Armadale ferry route is predominantly used by leisure travellers as opposed to businesses or residents (who have transferred to the A87(T) route via the Skye Bridge) and this suggests that the increase in use has been from leisure travellers.
Policy Integration
The Environmental Statement for the project contains a detailed assessment against the planning policies in place at the time of the project's development and implementation. The assessment concluded that the proposed realignment of the A830(T) between Arisaig and Loch Nan Uamh accords with the policies contained within the Highland Council Structure Plan and the Lochaber Local Plan in respect of their objective of promoting the economic development of the area by improving transport links.
The Environmental Statement highlighted areas of potential conflict with development plan policies with regards to the impact of the project on aspects of the natural and built environment. No evidence has been found to challenge any of the conclusions.
Integration: Key Findings
Stakeholder feedback indicates that the interchange experience has been enhanced for bus passengers as a result of more reliable connections and that the project has played a role in encouraging the use of the Mallaig to Armadale ferry route.
The A830(T) Arisaig to Loch Nan Uamh project accords with the policies contained within the Highland Structure Plan and the Lochaber Local Plan in respect of their objective of promoting the economic development of the area by improving transport links.
A.1.7 Accessibility & Social Inclusion
Community Accessibility
Measures to mitigate impacts to cyclists and pedestrians were implemented during the project, with access to Rights of Way protected, and a dedicated cycle / pedestrian track provided along the length of the improvement. During the environmental mitigation measures review, the cycle / pedestrian track was observed as being in regular use, however, no evidence has been identified to confirm whether there has been a change in the levels of use of this route by active travel users.
It is likely that accessibility improvements will have been felt by local active travel users in and around Arisaig where the segregated track links with local cycling routes. It is difficult, however, to conclude whether any wider accessibility impacts have resulted from this active travel element of the project.
Stakeholder Feedback
The Shiel Buses service between Mallaig and Fort William operates along the A830(T) route enhanced by the improvement. Anecdotal evidence indicates that, as a result of the A830(T) Arisaig to Loch Nan Uamh project, journey time reliability has improved, allowing Shiel Buses to provide a more reliable timetable, which has in turn improved the interchange experience for passengers linking with the Acharacle to Fort William connection. No quantitative evidence has been identified to confirm whether the improvement in journey times has led to increased accessibility through the provision of additional services or revised service patterns.
Anecdotal evidence from Highlands and Islands Enterprise suggests that the project has had a positive impact on community access and has improved supply chains and linkages between the areas of Mallaig and Arisaig to Fort William.
Accessibility & Social Inclusion: Key Findings
A new cycle / pedestrian track has been implemented as part of the project and has been observed to be in regular use. It is, therefore, likely that local accessibility for pedestrians and cyclists has been enhanced as a result of the project.
Stakeholder feedback indicates that the reduction in journey times and improvement in journey time reliability has had a positive impact on community access and has improved supply chains and linkages between the areas of Mallaig and Arisaig to Fort William.
Investment Costs
Comparison Between Predicted and Out-turn Costs
The out-turn and predicted project costs are shown in Table A.1.6. As schemes progress towards procurement, there is normally greater confidence in their cost predictions and optimism bias can be reduced. Due to the timing of the pre-tender assessment for the A830(T) Arisaig to Loch Nan Uamh project, optimism bias was not considered to be required.
Cost to Government: Key Findings
The out-turn cost of the A830(T) Arisaig to Loch Nan Uamh project was approximately £0.7m (4%) lower than was predicted at the time of the assessment.
A.1.9 Value for Money
Initial Indications
The pre-tender economic appraisal results for the A830(T) Arisaig to Loch Nan Uamh project predicted a Net Present Value (NPV) of -£4.55m and Benefit to Cost Ratio (BCR) of 0.77 under the high traffic growth forecast scenario.
The appraisal was updated at the post-tender stage and with European funding available, the scheme was considered to deliver value for money.
Based on the comparisons presented in sections A.1.5 and A.1.8, which suggest that the benefits may have been underestimated and indicate that the out-turn cost is less than predicted, the NPV and BCR of the project is likely to be greater than predicted at the pre- and post-tender stages.
Value for Money: Key Findings
It is judged that the project is likely to deliver value for money over and above that predicted as part of the project's assessment.
A.1.10 Achievement of Objectives
As specific indicators to measure the performance of the A830(T) Arisaig to Loch Nan Uamh project against its objectives have not been developed, an initial indication of how the project is progressing towards achieving its objectives is based on the pre opening data available, supplemented by post opening data collected as part of the evaluation.
Initial Indications
A summary of the evaluation, providing an indication of how the A830(T) Arisaig to Loch Nan Uamh project is progressing towards achieving its objectives, is presented in Table A.1.7.
A.2 A7(T) Auchenrivock
A.2.1 Introduction
Project Overview
The project, located on the A7(T) approximately 3km south of Langholm, involved the off-line construction of 1.6 kilometres of single 2-lane carriageway and 1.7 kilometres of wide single 2-lane carriageway, to improve overtaking opportunities, on the A7(T) and includes two dedicated right turn ghost island junctions allowing access to Langholm.
The existing route was de-trunked, with part of the carriageway converted into a cycleway / footpath, with the intention of providing local people and tourists with the opportunity to switch to a more sustainable mode of transport.
The general location of the project is shown in Figure A.2a.
The A7(T) Auchenrivock project was officially opened to traffic on 18th June 2009.
Project Objectives
The objectives of the A7(T) Auchenrivock project were set as follows:
- to improve the operational performance, level of service and road safety on the A7 by reducing the effects of driver stress and journey times;
- to improve and increase the number of overtaking opportunities to eradicate the conflicts between long distance users, local and agricultural traffic;
- to incorporate measures for non-motorised users;
- to mitigate the environmental impact of the new works where possible; and
- to achieve good value for money for both taxpayers and transport users.
Evaluation Methodology
The A7(T) Auchenrivock project has been evaluated using network traffic indicators and comparisons against the above objectives and the following criteria:
- Environment;
- Safety;
- Economy;
- Accessibility & Social Inclusion;
- Costs to Government; and
- Value for Money.
As the evaluation focuses on impacts relating to the project objectives, a specific evaluation against the Integration criterion has not been undertaken.
The evaluation is supported by the consideration of network traffic indicators, including traffic volumes, overtaking opportunities and travel times presented in the following section.
Traffic Volumes
The location of the Automatic Traffic Counter (ATC) within the study area is shown in Figure A.2a.
Comparison Between Pre and Post Opening Traffic Flows
The Annual Average Daily Traffic (AADT) flows pre and post project opening on the A7(T) route within the vicinity of the project are presented in Table A.2.1.
|
ATC Reference |
AADT by Year |
|||||
|---|---|---|---|---|---|---|
|
2006 |
2007 |
2008 |
2009 |
2010 |
2011 |
|
|
A7(T) South of Langholm |
||||||
|
JTC08199 |
3,605 |
3,570 |
3,586 |
Year of Opening |
3,431* |
3,434* |
* flows based on partial data
A comparison between pre and post opening traffic volumes on the A7(T) south of Langholm indicates that traffic flows in 2010 were around 150 vehicles per day (approximately 4%) lower than 2008 flow levels. Flows in 2011 were consistent with 2010 levels.
Given the nature of the A7(T) Auchenrivock project, changes in traffic are not likely to be as a consequence of changes to the carriageway standard and may be as a result of general reductions in traffic volumes across the wider trunk road network due to the economic downturn experienced during the evaluation period.
Comparison Between Predicted and Actual Traffic Flows
The opening year flow comparisons for the A7(T) Auchenrivock project are based on AADT flows from 2010 as this was the first year of post opening traffic data available from Transport Scotland's traffic counter within the study area. Whilst the 2010 traffic data only covers the period from August to December, a review of the data from previous years indicates that the average flow over this period is reasonably consistent with the AADT flow.
As part of the project's appraisal, National Road Traffic Forecasts (NRTF) low and high traffic growth factors were applied to the modelled 2009 opening year traffic flows to derive future modelled assessment year traffic flows. Predicted traffic flows for 2010 have been derived by interpolating between the modelled assessment year, design network flows.
A summary of the actual and predicted traffic data is shown in Table A.2.2 below.
* 2010 flows based on available data (August to December)
The comparison between predicted and actual AADT flows in Table A.2.2 indicates that the predicted 2010 flow (derived by interpolating between the modelled assessment year, design network flows) was 5% and 14% greater than the observed 2010 flow under low and high traffic growth forecast scenarios respectively.
Whilst this comparison indicates that traffic growth on the A7(T) has fallen short of the assumed NRTF forecasts, the difference is within accepted limits. It is recognised that there has been a general reduction in traffic volumes across the wider trunk road network in recent years due to the economic downturn that may in part account for the difference.
Carriageway Standard Assessment
In order to satisfy the project objectives, a wide single carriageway was constructed over a section of the A7(T), at Auchenrivock, providing increased overtaking opportunities to help reduce platooning as well as to reduce journey times and improve journey time reliability.
An assessment of the carriageway standard according to TA 46/97 - Economic Assessment and Recommended Flow Ranges for New Rural Road Links, which applied at the time of the project design, is shown in Table A.2.3, based on the observed 2010 traffic flow.
|
Opening Year AADT* |
TA 46/97 Standard |
Constructed Standard |
|---|---|---|
|
3,431 |
Single 2-Lane |
Single 2-Lane & Wide Single 2‑Lane |
* 2010 flows based on available data (August to December)
Although the carriageway assessment indicates that the observed 2010 flow lies within the flow range appropriate for a single 2-lane standard of carriageway, given the project objectives, the constructed wide single 2-lane carriageway section is considered appropriate.
Overtaking Opportunities
Post Opening Overtaking Opportunities
Based on the evaluation of other projects with a comparable standard of carriageway for which overtaking surveys have been carried out, the provision of the wide single 2-lane carriageway is judged to have a positive impact on the number of overtaking manoeuvres. As a consequence of providing overtaking opportunities, the project is also likely to help reduce platooning.
Stakeholder feedback
Dumfries and Galloway Council has indicated that overtaking opportunities have increased significantly as a result of the project.
Travel Times
Change in Travel Times
Based on the evaluation of other projects with a comparable standard of carriageway for which journey time data is available, the provision of the wide single 2-lane carriageway is judged to reduce journey times.
Stakeholder feedback
Dumfries and Galloway Council has indicated that the project has had a positive impact on journey times and journey time reliability.
A.2.3 Environment
Review of Environmental Mitigation Measures
The environmental mitigation measures originally proposed for the A7(T) Auchenrivock project were obtained from the project's Environmental Statement. A review of the environmental mitigation measures was carried out in July 2011, which confirmed that the majority of measures committed within the Environmental Statement were in place and were providing appropriate levels of mitigation.
Noise and Air Quality
Given the rural nature of the A7(T) Auchenrivock project, no significant impact on noise and air quality is expected. It is therefore not appropriate to evaluate the project's impact on noise and air quality.
Environment: Key Findings
The review of mitigation measures implemented for the A7(T) Auchenrivock project confirmed that the majority of measures committed within the Environmental Statement were in place. Whilst some variations from the proposed mitigation measures had been identified, these were not considered to have had a material detrimental impact on the general integration of the project into its surrounding.
A.2.4 Safety
Accidents
Comparison Between Pre and Post Opening Personal Injury Accident Numbers
The locations and severities of personal injury accidents occurring within the vicinity of the A7(T) Auchenrivock project 3 years before and 1 year after project completion are shown in Figures A.2b and A.2c.
A summary of the accident data is shown in Table A.2.4.
|
Period |
Fatal |
Serious |
Slight |
Total Accidents |
|---|---|---|---|---|
|
3 Years Before |
||||
|
A7(T) |
1 |
0 |
0 |
1 |
|
1 Year After |
||||
|
A7(T) |
0 |
0 |
0 |
0 |
As can be seen from Table A.2.4, no personal injury accidents occurred in the 1 year period following the opening of the project in comparison to one personal injury accident (fatal) in the 3 years before opening, suggesting a potential improvement in road safety.
Road Safety Audits
The Stage 4 Road Safety Audit (RSA) was carried out in August 2010. The RSA report confirmed that no personal injury accidents had occurred within the vicinity of the project in the 1 year period after project opening. The report noted that a damage only accident had occurred within the vicinity of the project in the 1 year after opening and involved a single vehicle losing control and colliding with a safety barrier. An issue surrounding the speed of vehicles on the new section has been noted and the local police are monitoring the situation.
It was also noted that during a period of adverse weather conditions in December 2009, approximately 20 vehicles were stranded on the 8% uphill gradient at the northern end of the project due to the blizzard conditions.
The audit concluded that the new road layout at Auchenrivock is operating safely and efficiently.
Safety: Key Findings
An assessment of the 1 year post opening personal injury accidents and a review of the Stage 4 RSA report, suggests that while an issue surrounding the speed of vehicles on the new section has been noted, the A7(T) Auchenrivock project is operating safely.
Transport Economic Efficiency
Comparison Between Predicted and Actual Traffic Flows
The comparison between predicted and actual traffic flows, presented in section A.2.2, can be considered a proxy for whether the predicted economic benefits of the project are likely to be realised.
The comparison indicates that the predicted 2010 flows were between 5% and 15% greater than the observed 2010 flows on the A7(T) depending on the growth scenario considered. This overestimation may in part be due to the general economic downturn.
Economy: Key Findings
The difference between predicted and actual AADT flows suggests that, due to external factors that could not have readily been foreseen at the time of assessment, the economic benefits of the project will have been overestimated.
A.2.6 Accessibility & Social Inclusion
Community Accessibility
It is likely that accessibility improvements will have been felt by local active travel users in and around Auchenrivock due to the provision of the new cycleway / footpath. Public transport uses the de-trunked A7 route and bus passengers are likely to feel safer and less intimidated by traffic as a result.
Cycling Audits
A Cycle Audit for the A7(T) Auchenrivock project was carried out in June 2009, as part of the RSA.
The audit report notes the following to address potential issues with the measures provided for cyclists as part of the A7(T) Auchenrivock project:
- Signage for cyclists and motor vehicles be improved at access points to the bypassed carriageway;
- Bollards be erected at the access point to the bypassed carriageway; and
- Reflectors be attached at the northern access to the bypassed carriageway to mitigate risk to cyclists.
Accessibility & Social Inclusion: Key Findings
The Cycle Audit carried out as part of the RSA for the A7(T) Auchenrivock project provides recommendations to address potential issues with the measures provided for cyclists.
Investment Costs
Comparison Between Predicted and Out-turn Costs
The out-turn and predicted project costs are shown in Table A.2.5.
Cost to Government: Key Findings
The out-turn cost of the A7(T) Auchenrivock project is approximately £1.0m (21%) greater than was predicted at the time of assessment.
A.2.8 Value for Money
Initial Indications
The economic appraisal results for the A7(T) Auchenrivock project predicted a Net Present Value (NPV) of £1.19m and Benefit to Cost Ratio (BCR) of 1.19 under the 60/40 traffic growth forecast scenario.
Based on the comparisons presented in sections A.2.5 and A.2.7, which suggest that the benefits may have been overestimated and indicate that the out-turn cost is greater than predicted, the NPV and BCR of the project are unlikely to be as great as predicted.
Value for Money: Key Findings
Although the NPV and BCR are unlikely to be as great as predicted at the time of assessment, it is judged that the project will continue to provide benefits to road users.
A.2.9 Achievement of Objectives
As specific indicators to measure the performance of the A7(T) Auchenrivock project against its objectives have not been developed, an initial indication of how the project is progressing towards achieving its objectives is based on the pre opening data available, supplemented by post opening data collected as part of the evaluation.
Initial Indications
A summary of the evaluation, providing an indication of how the A7(T) Auchenrivock project is progressing towards achieving its objectives, is presented in Table A.2.6.
A.3 A9(T) Bankfoot
A.3.1 Introduction
Project Overview
The project involved removing right turn manoeuvres across the main A9(T) carriageway to/from the B867 and Bankfoot Village through improvements to the existing A9(T)/B867 junction and the realignment of a minor road to the north, providing left-in, left-out junctions on the A9(T) for both northbound and southbound traffic.
The general location of the project is shown in Figure A.3a.
The A7(T) Bankfoot project was officially opened to traffic on 28th August 2009.
Project Objectives
The objectives of the A9(T) Bankfoot project reflect those set for the A9(T) route, which were as follows:
- to provide a good, quick and reliable inter urban road link;
- to improve road safety;
- to minimise the intrusion of the road and traffic on the environment; and
- to achieve good value for money.
Evaluation Methodology
The A9(T) Bankfoot project has been evaluated using network traffic indicators and comparisons against the above objectives and the following criteria:
- Environment;
- Safety;
- Economy;
- Costs to Government; and
- Value for Money.
As the evaluation focuses on impacts relating to the project objectives, specific evaluations against the Integration and Accessibility & Social Inclusion criteria have not been undertaken.
The evaluation is supported by the consideration of network traffic indicators, including traffic volumes and travel times presented in the following section.
Traffic Volumes
The locations of the Automatic Traffic Counters (ATCs) within the study area are shown in Figure A.3a.
Comparison Between Pre and Post Opening Traffic Flows
The Annual Average Daily Traffic (AADT) flows pre and post project opening on the A9(T) route within the vicinity of the project are presented in Table A.3.1.
A comparison between pre and post opening traffic volumes on the A9(T) north of Luncarty indicates that traffic flows in 2010 were around 200 vehicles per day (approximately 1%) lower than 2008 flow levels. Flows in 2011 were marginally higher than 2008 levels. Traffic volumes on the A9(T) at Dunkeld have seen a reduction of around 600 vpd (approximately 4%) between 2008 and 2010 with flows in 2011 around 200 vpd (approximately 2%) higher than 2008 levels.
Given the nature of the A9(T) Bankfoot project, changes in traffic are not likely to be as a consequence of changes to the junction layout and carriageway.
Comparison Between Predicted and Actual Traffic Flows
The opening year flow comparisons for the A9(T) Bankfoot project are based on AADT flows from 2010 as this was the first full year of reliable traffic data available from Transport Scotland's traffic counters within the vicinity of the project.
As part of the project's appraisal, National Road Traffic Forecasts (NRTF) central traffic growth factors were applied to the 2005 base year traffic flows to derive opening and future modelled assessment year traffic flows. Predicted traffic flows for 2010 were derived by factoring the 2005 base year flows used in the economic assessment with NRTF central traffic growth factors.
A summary of the actual and the predicted traffic data is shown in Table A.3.2 below.
* 2010 flows (first full year of ATC data available)
The comparison between predicted and actual AADT flows in Table A.3.2 indicates that the predicted 2010 flows were between 15% and 25% lower than the observed 2010 flows.
Carriageway Standard Assessment
As the A9(T) Bankfoot project involved the construction of an improved junction layout, as opposed to a new section of carriageway, it has not been necessary to carry out a carriageway standard assessment.
Travel Times
Change in Travel Times
Whilst journey times for some local trips accessing the A9(T) may have marginally increased as a result of the revised junction layout due to the removal of right turns to/from Bankfoot village, it can be expected that journey times on the A9(T) carriageway itself over the extents of the improvement will have reduced, and journey time reliability improved, in both directions of travel as a result of removing delays to mainline traffic caused by right turning vehicles.
A.3.3 Environment
Review of Environmental Mitigation Measures
The environmental mitigation measures originally proposed for the A9(T) Bankfoot project were obtained from the project's Environmental Statement. A review of the environmental mitigation measures was carried out in July 2011, which confirmed that the majority of measures committed within the Environmental Statement were in place and were providing appropriate levels of mitigation.
As part of the review the following areas were identified that require maintenance:
- several locations throughout the project where the growth of weeds has been significant;
- rank weed growth on the rock blanket located on the north eastern cutting slope; and
- the SUDS pond which has been overgrown by weeds including dock and clover.
Noise and Air Quality
As no significant impact on noise and air quality is expected as a result of the A9(T) Bankfoot project, it is not appropriate to evaluate the project's impact on noise and air quality.
Environment: Key Findings
The review of mitigation measures for the A9(T) Bankfoot project confirmed that the majority of measures committed within the Environmental Statement were in place. Whilst some variations from the proposed mitigation measures had been identified, these were not considered to have had a material detrimental impact on the general integration of the project into its surrounding.
Maintenance is required to avoid any significant impact on the tree and hedgerow planting within the vicinity of the project.
A.3.4 Safety
Accidents
Comparison Between Pre and Post Opening Personal Injury Accident Numbers
The locations and severities of accidents occurring within the vicinity of the A9(T) Bankfoot project 3 years before and 1 year after project completion are shown in Figures A.3b and A.3c.
A summary of the personal injury accident data is shown in Table A.3.3.
|
Period |
Fatal |
Serious |
Slight |
Total Accidents |
|---|---|---|---|---|
|
3 Years Before |
||||
|
A9(T) |
0 |
0 |
6 |
6 |
|
1 Year After |
||||
|
A9(T) |
0 |
0 |
0 |
0 |
As can be seen in Table A.3.3, no personal injury accidents occurred in the 1 year period following the opening of the project in comparison to six (slight) personal injury accidents in the 3 years before opening, suggesting a potential improvement in road safety.
Road Safety Audits
The Stage 4 Road Safety Audit (RSA) was carried out in May 2012. The RSA report confirmed that no personal injury accidents had occurred within the vicinity of the project in the 1 year after project opening. The RSA noted a skid risk from vehicles overrunning filter drain material and scattering it on the carriageway surface.
Safety: Key Findings
An assessment of the 1 year post opening personal injury accidents and a review of the Stage 4 RSA report, suggests that the A9(T) Bankfoot project is operating safely.
A skid risk from vehicles overrunning the filter drain and scattering it on the carriageway surface has been noted.
Transport Economic Efficiency
The comparison between predicted and actual traffic flows, presented in section A.3.2, can be considered a proxy for whether the predicted economic benefits of the project are likely to be realised.
Comparison Between Predicted and Actual Traffic Flows
The comparison between predicted and actual traffic flows indicates that the predicted 2010 flows were 20% to 30% lower than the observed 2010 flows on the A9(T). The project may, therefore, deliver additional benefits to road users than those predicted as part of the project's appraisal.
Economy: Key Findings
The difference between predicted and actual AADT flows is likely to have resulted in an underestimation of road user benefits.
Investment Costs
Comparison Between Predicted and Out-turn Costs
The out-turn and predicted project costs are shown in Table A.3.4.
Cost to Government: Key Findings
The out-turn cost of the A9(T) Bankfoot project was approximately £0.8m (60%) greater than was predicted at the time of the assessment.
A.3.7 Value for Money
Initial Indications
The economic appraisal results for the A9(T) Bankfoot project predicted a Net Present Value (NPV) of £0.97m and Benefit to Cost Ratio (BCR) of 1.97 under the central traffic growth forecast scenario.
Based on the comparisons presented in sections A.3.5 and A.3.6, which suggest that the benefits may have been underestimated and indicate that the out-turn cost is greater than predicted, the NPV and BCR of the project is unlikely to be as great as predicted.
Value for Money: Key Findings
Whilst the NPV and BCR are unlikely to be as great as predicted at the time of assessment, it is judged that the project will continue to provide a benefit to road users.
A.3.8 Achievement of Objectives
As specific indicators to measure the performance of the A9(T) Bankfoot project against the route objectives have not been developed, an initial indication of how the project is progressing towards achieving its objectives is based on the pre opening data available, supplemented by post opening data collected as part of the evaluation.
Initial Indications
A summary of the evaluation, providing an indication of how the A9(T) Bankfoot project is progressing towards achieving its objectives, is presented in Table A.3.5.