Transcript Evidence Base Presentation
A9 Safety Group
Accident and Speed Analysis - Evidence Base 7 March 2013
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
Presentation
Contents
• Route Overview • Accident Analysis • Speed Analysis • Current Speed Enforcement • Next Steps / Further Considerations
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
Route Overview – Traffic Volumes • Indicative Annual Average Daily Traffic Flows (2012)
Section
Dunblane to Perth Perth to Luncarty Luncarty to Pitlochry Pitlochry to Inches Inches to Raigmore Raigmore to Longman Longman to Dornoch Dornoch to Scrabster
AADT
25,000 22,500 13,500 8,500 26,500 37,500 6,000 2,500
% By Vehicle Class Car PSV M’cycle
81.8% 87.7% 78.7% 77.3% 89.2% 0.4% 0.6% 0.6% 0.8% 0.7% 0.4% 0.7% 1.4% 0.4% 0.5%
LGV / HGV <7.5T
9.0% 6.9% 12.4% 14.1% 7.1%
HGV >7.5T
8.4% 4.0% 6.9% 7.4% 2.5%
Route Overview – Traffic Volumes • Noticeable seasonal variation in traffic flows on the route (example at Dunkeld below)
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
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
Route Type Slight
Dual 142
Serious
42
Fatal
8
Total
192 National Av.
KSI Ratio
0.26
0.24
20% 15% 10% 5% 0%
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)
A9 NE Unit A9 NE Unit 20% 15% 10% 5% 0%
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
Manoeuvre / Causation
Junction Manoeuvre Illness / Disability Pedestrian Impaired by Alcohol Loss of Control Failed to Look
Number
4 1 1 1 1
% of Total
50% 12.5% 12.5% 12.5% 12.5%
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
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
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
Route Type Slight
Single 203
Serious
41
Fatal
9
Total KSI Ratio
253 0.20
National Av 0.24
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)
A9 NW Unit A9 NW Unit 15% 15% 10% 10% 5% 5% 0% 0%
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
Manoeuvre / Causation
Junction Manoeuvre Moved over Centre Line Overtaking Loss of Control Ped Stepped Out Wrong Side of Road (Foreign Driver)
South of Dornoch Number % Total
1 33.3% 1 1 33.3% 33.3%
North of Dornoch Number % Total
1 3 1 1 16.7% 50% 16.7% 16.7%
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
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)
Route Type Slight
Single Dual WS2+1 Total 141 79 1 221
Serious Fatal
41 14 0 55 25 6 0 31
Total
207 97 1 307
KSI Ratio
0.32
0.21
0.00
0.28
% of Route Total Total
68%
KSI
77% 32% <1% 100% 23% 0% 100%
15% 10% 5% 0%
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%)
A9 NW Unit A9 Single NW Unit 25% 20% 15% 10% 5% 0%
10% 5% 0%
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)
A9 Single NW Unit A9 Dual NW Unit 10% 5% 0%
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
Involved Vehicle Type
Car Goods Vehicles<7.5T
HGV>7.5T
Motorcycle PSV Other Minibus
Number of Accidents % of Total
3 2 1 7 5 22 7 71% 23% 23% 16% 10% 6% 3%
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
Manoeuvre / Causation
Overtaking Moved out of Lane / Drifting Loss of Control Pedestrian Stepped Out Junction Manoeuvre Following Too Close
Number
3 3 8 7 6 4
% of Total Involved HGV>7.5T
25.8% 22.6% 19.0% 12.9% 9.7% 9.7% 0 2 1 1 0 3
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
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
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 Location Luncarty Moulinearn Killiecrankie Dalwhinnie Kincraig Moy North of Inveralmond Greenloaning Dunblane Bypass North of Auchterarder Carriageway Type Single Dual Single Single Single Single Dual Dual Dual Dual
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
Vehicle Type
Cars
Dunblane to Perth Perth to Inverness Single Av Speed (mph) %Above Limit Av Speed (mph) %Above Limit
67.8
HGVs>7.5 tonnes 53.8
39.7% 57.6
51.5
30.2% >95%* Motorcycles 70.1
50.9% 57.9
29.2%
Perth to Inverness Dual Av Speed (mph) %Above Limit
67.0
32.1% 53.5
>75%* * Approximate value
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
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
Section No of Mob Sites
Full Route Dunblane to Perth Perth to Inverness (Single) Perth to Inverness (Dual) Inverness to Dornoch Dornoch to Scrabster 109 9 52 18 17 13
Offences
10,238 4,589 4,491 834 189 135
Deployment Hours Offences / Hour
1,513 395 707 209 112 88 6.8
11.6
6.4
4.0
1.7
1.5
A9 Post Code Analysis – Offenders
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
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
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
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
Next Steps…… • Discuss key outcomes • Reach outline consensus on issues • Circulate supporting reports • Identify appropriate measures
A9 Safety Group
Accident and Speed Analysis - Evidence Base 7 March 2013