1 / 34

A9 Safety Group

Accident and Speed Analysis - Evidence Base 7 March 2013. A9 Safety Group. Presentation Purpose. To provide a summary of the accident analysis and review of vehicle speeds and speed enforcement on the route

adonica
Download Presentation

A9 Safety Group

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Accident and Speed Analysis - Evidence Base 7 March 2013 A9 Safety Group

  2. Presentation Purpose • To provide a summary of the accident analysis and review of vehicle speeds and speed enforcement on the route • All supporting reports and analysis to be circulated in due course to group members for more detailed consideration

  3. Presentation Contents • Route Overview • Accident Analysis • Speed Analysis • Current Speed Enforcement • Next Steps / Further Considerations

  4. Route Overview • Route serving a mix of local and strategic traffic movements, connecting major conurbations and serving smaller towns • Critical link between the Central Belt and the North • Mix of dual with at grade junctions, single, WS2+1 and dual route provisions

  5. Route Overview – Traffic Volumes • Indicative Annual Average Daily Traffic Flows (2012)

  6. Route Overview – Traffic Volumes • Noticeable seasonal variation in traffic flows on the route (example at Dunkeld below)

  7. Accident Analysis Approach • Route split into three distinct parts • STATS19 analysis (2007 to 2011) • Comparisons made against wider trunk road averages • Consideration made to standard STATS19 indicators (vehicle type, manoeuvre, weather / lighting conditions, road surface, driver age, driver postcode, time of day etc) • Route wide approach to identify key themes • More detailed review of police report for all fatal accidents • Targeted analysis by section (acc rate and KSI rate) • Identification of cluster locations to capture localised issues

  8. A9 Dunblane to Perth – Summary Statistics • Accident Rate comparable with trunk road national average • KSI Ratio marginally higher than trunk road national average (0.26 v 0.24) • Annual accident levels declining

  9. A9 Dunblane to Perth – Key Safety Themes • Higher number of HGV>7.5Ts involved in accidents (17% v 9% NE unit average) • 53% of right turn accidents are KSIs (compared to 29% NE unit average)

  10. A9 Dunblane to Perth – Fatal Accident Analysis • 4 out of 8 fatal accidents occurred at a junction • 3 out of 8 fatal accidents involved HGVs (1 accident with HGV>7.5T) • Only 1 of the fatal accidents was a single vehicle accident

  11. A9 Dunblane to Perth–Section Analysis • Two section accident rates are higher than the national average (7.7pia/100mvk) • Dunblane to Greenloaning (8.8pia/100mvk) • Influence of accidents in 2007 • Blackford to Shinafoot (11.8pia/100mvk) • Over 50% of accidents were ‘single vehicle’ (35% on wider route and NE unit) • 56% of accidents involved roadside strikes (31% route average, 35% NE unit average) and the majority occurred in the Gleneagles area • Proposal under consideration as part of on-going SRS work to improve roadside safety

  12. A9 Dunblane to Perth – Cluster Identification • 14 cluster sites identified with concentration of accidents • 10 of these sites have previously been identified / investigated / treated • Remaining 4 cluster sites be programmed for investigation and analysis for common causations • Auchterarder Bypass • Balhaldie Services • Crieff Road • Inveralmond Roundabout

  13. A9 Inverness (Tore) to Scrabster – Summary Statistics • Accident rate is higher than the trunk road national average (24.3 v 18.7 pia/100mvk) • But lower accident frequency due to lower traffic volumes • KSI Ratio is less than the trunk road national average (0.20 v 0.24) • Annual accident levels declining

  14. A9 Inverness (Tore) to Scrabster – Key Safety Themes • ‘Turning right’ the most common vehicle manoeuvre in accidents (13.5% compared to 6.1% NW unit average) • ‘Failed to look properly’, ‘failed to judge other persons speed’, ‘careless/reckless’ and ‘poor turn’ the most common contributory factor in accidents • 43% of accidents occurred at a junction (compared to 26% NW unit average)

  15. A9 Inverness (Tore) to Scrabster – Fatal Accident Analysis • 9 fatal accidents (3 south and 6 north of Dornoch Bridge) • 50% of fatals north of Dornoch Bridge were due to ‘loss of control’ • 3 out of 5 fatals north of Dornoch Bridge were single vehicle

  16. A9 Inverness to Scrabster – Cluster Identification • 9 cluster sites identified • 6 sites addressed / being addressed through safety improvements • 1 investigation identified no treatable common factors • 2 sites currently under more detailed investigation • Drummond Junction • Dunrobin Castle Junction

  17. A9 Perth to Inverness (Tore) - Overview • Varying route provision requires analysis by route type • Single carriageway makes up 65% of the route length • 68% all accidents occurred on single carriageways • 77% of all KSI accidents occurred on single carriageways • Single carriageway KSI ratio (0.32) > trunk road national av. (0.24)

  18. A9 Perth to Inverness (Tore) – Key Themes • HGV>7.5Ts involved in 12.4% of accidents (compared to the NW unit average of 6.1%) • HGV>7.5T involved in 22.8% of accidents on single carriageways • Goods vehicles<7.5T involved in 13.6% of accidents on single carriageways (compared to NW unit average of 7.0%)

  19. A9 Perth to Inverness (Tore) – Key Themes • Similar contributory factors are higher than the NW unit average on single and dual route types • However ‘fatigue’ more prevalent on single carriageway sections (4.1% compared to 0.8% on dual and 1.6% NW unit average) • And ‘sudden braking’ more prevalent on dual carriageway sections (6.0% compared to 3.9% on single and 4.0% NW unit average)

  20. A9 Perth to Inverness (Tore) – Fatal Accident Analysis • 25 out of 31 fatal accidents occurred on single carriageways • HGVs>7.5T involved in 23% of fatal accidents

  21. A9 Perth to Inverness (Tore) – Fatal Accident Analysis • ‘Overtaking’, ‘moved out of lane’ and ‘loss of control’ the most common causes of fatal accidents • Only 1 overtaking accident involved an HGV>7.5T

  22. A9 Perth to Inverness (Tore) – Section Analysis • 3 out of 25 route sections were identified to have an accident rate higher than the national average • Bankfoot (9.4 pia/100mvk) • Faskally (50.9 pia/100mvk) • Meall Mor to Kessock Bridge (9.0 pia/100mvk) • Road improvements delivered in 2009/2010 at Bankfoot and Faskally and in 2012/2013 across the Meall Mor to Kessock Bridge section

  23. A9 Perth to Inverness – Cluster Identification • 9 cluster sites identified • 6 sites addressed / being addressed through safety improvements • 1 site investigated but no works taken forward (Munclochy Junction) • 1 site investigated but no treatable common factors identified • 1 site currently under more detailed investigation • Granish (A95) Junction

  24. A9 Summary of Vehicle Speeds - Approach • Speed data by vehicle class collected at 10 SRTBd counter locations across the route • Summary of data from full neutral months in 2012 • Data summarised by speed bins, by hour, max speed to be used to inform existing speed enforcement regime

  25. A9 Vehicle Speed Summary – Average Speeds • Evidence of vehicles travelling above the posted speed limit at every counter location interrogated • Most pronounced for HGVs>7.5Ts * Approximate value

  26. A9 Current Speed Enforcement (2012) • Speed Enforcement by Northern, Tayside and Central Police and Safety Camera Partnerships (SCPs) • Police enforcement through patrols on the route • SCP enforcement through 5 Fixed Safety Cameras • Dunblane to Perth (3) • Perth to Inverness (2) • And widespread mobile enforcement (109 sites) across the entire route

  27. A9 Current Safety Camera Deployment • Fixed cameras had an average of 0.1 offences per hour in 2012 • SCPs deployed mobile enforcement on the A9 for a total of approximately 1,500 hours in 2012

  28. A9 Post Code Analysis – Offenders

  29. A9 Existing Speed Enforcement Regime • Speed enforcement undertaken through a collection of fixed sites, mobile sites and police patrols • Higher offence rates recorded south of Inverness • Offenders typically reside across Scotland's key areas of population

  30. A9 Evidence Base Summary • Accident Analysis • Dunblane to Perth • High severity of accidents at junctions • High number of single vehicle, roadside strike accidents in the Gleneagles area • Inverness to Scrabster • High number of accidents at junctions • High proportion of fatal accidents north of Dornoch Bridge single vehicle and due to loss of control

  31. A9 Evidence Base Summary • Perth to Inverness • High number of HGV>7.5Ts in accidents, particularly on single carriageways • Fatigue contributing to accidents is more common on single carriageway sections • Sudden braking contributing to accidents is more common on dual carriageway sections • Vast majority of fatal accidents occurred on single carriageways • Overtaking, moved out of lane and loss of control most common manoeuvres in fatal accidents

  32. A9 Evidence Base Summary • Vehicle Speeds • Evidence of a significant proportion of vehicles exceeding the posted speed limit • Speed Enforcement • Highest offence rates recorded south of Inverness

  33. Next Steps…… • Discuss key outcomes • Reach outline consensus on issues • Circulate supporting reports • Identify appropriate measures

  34. Accident and Speed Analysis - Evidence Base 7 March 2013 A9 Safety Group

More Related