Simon Dando Contract Director Ringway Jacobs County Hall Walton Street Aylesbury Buckinghamshire HP20 1UY
COLLISION INVESTIGATION AND ANALYSIS REPORT.
A412 Uxbridge Road, Wexham. Five Points Roundabout to the County Boundary with Slough.
1. Introduction
Transport for Buckinghamshire is aware that there is a collision history on the A412 Uxbridge Road, with a large proportion specifically relating to drivers making turning manoeuvres into or out of junctions along the road. TfB are also aware of local concern regarding the speed of vehicles traveling on the A412, and requests for measures to reduce speed to be implemented. The two recent fatal collisions at the Black Park Road junction have renewed requests for junction improvements.
Extensive analysis has previously been undertaken to seek to identify any common factors in the collisions such as contributory factors, location, time of day, road condition, weather, driver details.
The data and information within this report relates to the period 01/01/2000 – 30/06/2016; it is relevant to look at this length of time as it is likely that the collision analysis and investigation which took place prior to the Billet Lane gap closure in 2008, the earliest major Local Safety Scheme that was implemented, related to at least 5 years “before” data. The period between deciding to pursue the implementation of a Local Safety Scheme, until its actual completion, is likely to have been at least 12 months, taking into account the planning, feasibility study, design stage and public consultation period. Therefore, for the most comprehensive picture of the collision history on this stretch of road and particularly at its junctions, it has been decided to include all collision data since 01/01/2000.
2. Road Environment
The 3km length of the A412 subject to this report can be separated into 3 sections by the difference in speed limits, although the road environment is the same throughout. The entire section from Five Points roundabout to the county boundary at Slough is a dual carriageway. The section from the roundabout to approximately 200m west is subject to a 40mph speed limit. The speed limit then increases to 60mph for 2 km until 200m southwest of the junction with Wexham Park Lane, where it returns to 40mph for 800m. The section that is currently subject to a 60mph speed limit was previously subject to National Speed Limit (70mph on a dual carriageway), but was reduced in January 2007 as part of the countywide speed limit review.
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3. Collision History
Between 01/01/2000 and 30/06/2016 there have been 172 reported injury collisions, of which, 7 were Fatal, 35 were Serious and 130 Slight.
The graph below shows how the collision figures have changed along the whole route between Five Points roundabout and the county boundary, since January 2000. It can be seen that since 2008 there has been a downward trend in collisions across the whole route.
• Of the 172 collisions, 30%(52) occurred in darkness and 28%(49) on a wet/damp road surface; this is in line with the county average of approximately 30% of collisions occurring in these conditions.
• The most common collision type was ‘Single Vehicle’ accounting for 22%(37), followed by ‘Right turn from a main road’ and ‘Right turn onto a main road’ which combined, accounted for 20%(35) collisions.
• The top 3 most commonly used contributory factors, as attributed by Thames Valley Police, were ‘Failed to look properly’, ‘Careless/reckless/In a hurry’ and ‘Failed to judge other persons path or speed’.
The table below indicates the decline in annual collisions by severity on this section of the A412 since 2006; 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Total Fatal 0 0 1 1 0 2 0 0 1 0 3 8 Serious 5 2 0 4 1 0 3 1 0 1 1 18 Slight 14 10 13 7 8 3 3 3 6 5 2 73 TOTAL 19 12 14 12 9 5 6 4 7 6 6 99
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The table below indicates the decline annual casualties by severity on this section of the A412 since 2006; 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Total Fatal 0 0 1 1 0 2 0 0 2 0 3 9 Serious 5 3 0 6 1 0 3 1 0 2 2 23 Slight 24 19 18 12 11 4 8 5 6 6 4 117 TOTAL 29 22 19 19 12 6 11 6 8 8 9 149
Fatal Collisions
Following a fatal collision in Buckinghamshire, a site visit is carried out between a member of the TfB Network Safety Team and a Thames Valley Police Traffic Management Officer. The purpose of this visit is to identify any factors directly related to the road environment which may have been contributory to the collision, with the intention of seeking to prevent the potential for repeat occurrences at road death sites.
In addition, the Network Safety Team aims to have a member of the team in attendance at all relevant Coroner’s Inquests into a fatal road collision (examples of inquests we do not attend are where it has already been confirmed by the Police that the collision was due to a medical episode i.e. heart attack, or where the collision occurred on a section of road under the authority of Highways England (i.e. the trunk road and motorway network). Following the inquest, notes on the evidence given are written up and distributed to the relevant people.
Between 01/01/2000 and 30/06/2016 there have been 7 fatal collisions on this stretch of the A412; the plot below shows the locations of each fatal collision. The circumstances of each collision are detailed below. There are an additional 3 fatal collisions in the last 2 months. These most recent collisions are shaded blue; we cannot comment on the circumstances until the Police investigation of each is complete and the inquests have taken place.
Light Contributory Location on A412 Uxbridge Date Time or Circumstances Factors as Road Dark Listed by TVP Impairment - Alcohol. Pedestrian under the
influence of alcohol Jct with George Green Failed to judge 25/11/2000 03:01 Dark attempted to cross the Road, Wexham other's path or A412 and was hit by an speed. HGV.
Inattention.
Car driver waiting in Failed to judge central refuge to perform other's path or U-turn manoeuvre to speed. 13/03/2003 16:35 Light Jct Billet Lane, Iver Heath travel back to Iver, pulled out in front of vehicle Looked but did travelling east. not see.
Car driver travelling southwest on A412 lost Approx. 200m northeast of control and crossed onto 16/04/2008 22:37 Dark jct with Black Park Road, central reservation then Loss of control. Wexham back across the carriageway. Driver ejected from vehicle.
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Car driver travelling Opposite Black Park southwest lost control 20/05/2009 18:46 Light Loss of control. Cottages and spun into trees on the nearside. Motorcyclist travelling Failed to judge northeast attempted to other's path or turn into Black Park speed. 23/07/2011 17:40 Light Jct with Black Park Road Road Jct at speed, lost control and hit the kerb, Learner or causing rider to be inexperienced thrown from motorbike. driver/rider. Failed to look properly.
Car driver parked facing Impaired by southwest standing to alcohol. the side of his car filling
with petrol, having run Impaired by Southwest of jct Black Park out. Goods Vehicle has 01/08/2011 01:35 Dark drugs (illicit or Road hit the rear of car and medicinal). caused fatal injuries to
car driver. Goods Vision affected Vehicle driver left the by road layout scene. (e.g. bend, winding road, hill crest). Car driver travelling Failed to look southwest, turned right properly. through central reservation gap to travel Failed to judge into Wexham Park Lane, other's path or 04/05/2014 13:01 Light Jct Wexham Park Lane across the path of speed. motorcyclist travelling northeast. Fatal injuries Careless, to both motorcyclist and reckless or in a car driver. hurry.
Just northeast of junction 17/10/2016 11:00 Light with Black Park Road Currently under Police investigation so no 150m north of the jct with 19/10/2016 19:50 Dark details are currently available for release to Black Park Road the public. 100m south of George 11/12/2016 23.26 Dark Green Rd
There are 3 areas within this length of the A412 with a concentration of collisions.
1. Billet Lane and Black Park Road Junctions
In the 8 years prior to Billet Lane gap being closed there were 16 injury collisions (1 fatal, 5 serious and 10 slight), 14 involved a turning movement at the gap. In this same period there were 19 collisions at and in the immediate vicinity of the junction with Black Park Road, of these 8 collisions involved a turning movement at the junction. Following the gap closure at Billet Lane in 2008, up to 30/06/2016 which is currently our most recent data, there has been 1 collision, naturally there have been no collisions involving turning movements. There have been a total of 18 collisions at, and in the
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immediate vicinity of, the Black Park Road junction; 13 of these collisions involved turning movements at the Junction.
This can be seen more clearly in the table below.
Before (01/01/2000-31/03/2008) After (01/04/2008-30/06/2016) Turning Turning Total Collisions Movement Total Collisions Movement Collisions Collisions Billet Lane 16 14 1 0 Black Park 19 8 18 13 Road
Black Park Road junction now has an almost identical “before” collision history as Billet Lane did prior to the decision to close the gap. Consideration should be made for the closure of the gap in the central reservation at the Black Park Road junction; however it must be acknowledged that there are 3 possible implications to this measure:
1. Most importantly, the turning collisions that are currently occurring at this junction are likely to be transferred/displaced onto the next available turning point on Uxbridge Road, which is Wexham Park Lane, therefore not solving the problem, simply moving it to another location.
2. The speeds of vehicles on A412 Uxbridge Road may increase, particularly in the southwest bound carriageway, as there is no physical reason to slow down and no chance that a vehicle will be making a turning movement ahead. This may then introduce speed related loss of control collisions.
3. The traffic that currently exits the Black Park Road junction and turns right to travel southwest may choose to use an alternative route, rather than having to turn left onto Uxbridge Road and travel up to Five Points roundabout to turn around. This may introduce other related issues onto the network.
2. Wexham Park Lane .
Between 01/01/2000 and 30/06/2016 there have been 13 injury collisions at the junction of A412 Uxbridge Road and Wexham Park Lane, 12 of these involved a turning movement from the central reservation across the path of vehicle on the A412 (1 fatal, 3 serious and 8 slight). Work was completed in summer 2016 to improve visibility at this junction from the central reservation gap. There are no reported injury collisions at this junction in 2015 and 2016.
It is extremely likely that if we were to close the gap at Black Park Road, then the turning collisions that are currently occurring would be transferred to the junction at Wexham Park Lane.
3. George Green.
Between 01/01/2000 and 30/06/2016 there have been 46 injury collisions in the 800m section at George green within the 40 mph section, 1 fatal, 10 serious and 35 slight. Over 30 of these are at the road junctions of Coronation Avenue (3 serious, 8 slight), George Green Road (1 fatal, 2 serious, 13 slight) or Church Lane (1 serious, 7 slight). The prominent factors involved in these collisions vary with single vehicle loss of control, rear shunts, non-
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compliance with signals, failing to look properly, exceeding the speed limit and aggressive driving featuring highly. Impairment by Alcohol also features higher than one would expect.
Both sets of traffic signals are currently due for imminent upgrades and renewal of the anti- skid surface on the southbound section at George Green Road
Safety Schemes installed.
Below are details of the Safety Schemes that have been implemented on the A412 Uxbridge Road.
• 01/03/2000 Bar Markings installed on the northbound approach to Five Points roundabout
• 01/10/2003 Installation of a VAS on the northbound approach to Five Points roundabout.
• 31/03/2008 Billet Lane gap closure and Black Park Road Junction realignment
• 08/04/2011 Installation of 2 VAS units and new advance direction signs on both approaches to Black Park Road.
• 21/05/2013 Black Park Road Junction - New temporary kerbing, red surfacing, new lining, and advanced junction layout sign installed. Vegetation cut back, increased police enforcement and installation of speed camera signs
• 22/01/2016 Black Park Road Junction - Permanent kerbing installed to replace the temporary build out. Changes made to the road markings within central crossover section.
• 14/03/2016 Wexham Park Lane junction – Construction of a hard landscaped area within the central reserve.
There has been an approximate total of over £250,000 spent on this section of the A412 in the past 15 years.
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Further Measures for Potential Consideration
Once the outcomes of the police investigation into the recent fatal collisions are known, TfB will be in a better position to understand the reasons why crashes continue to occur.
Possible counter measures which are subject to available funding include:
• Full Junction closures at Black Park Road and Wexham Park Lane
Pros: removes right turn manoeuvre and ‘U’ turns
Cons: Displaces turns (right and ‘U’ turns) to other junctions further south. (See comment above re turns at Wexham Pk La) Longer journeys via left turns and use of roundabouts. May increase speeds through the junction by removing the hazard but retaining a left turn onto the main carriageway.
• Partial Junction closure. Left turn only out of Black Park Road
Pros: Removes one right turn manoeuvre and may discourage ‘U’ turns Removes a movement and allows right turning vehicles into BPR to position themselves further forward. Diversion route facilitated by Five Points roundabout. Low cost and relatively simple to implement.
Cons: Displaces traffic to alternative routes, possibly Wexham Pk La. Longer journeys via left turns and use of roundabouts.
• Average speed cameras.
Pros: Enforces the speed limit, and therefore may reduce collisions and the severity of casualties. Will regulate speed through the junctions. Mounted on the central reservation would be able to enforce in both directions.
Cons: Requires TVP agreement and management Expensive to install and several may be required to cover the whole route and entry/exit points. May not stop excessive speed by unregistered vehicles or motorcycles (if forward facing – no front reg plate). Turning movements remain.
• Speed limit reduction.
Pros: Potential reduction in collisions and casualty severity. Stopping distances reduced, and reaction distance reduced.
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Cons: may not meet national assessment criteria. Drivers may not recognise the requirement to travel at a lower speed and therefore - Non-compliance may be higher. Enforcement commitment from police is required. Turning movements remain.
• Roundabout at Black Park Road.
Pros: Controls and prioritises turning movements at the junction Reduces speeds on the approach Retains turning movements and allows controlled ‘U’ turning.
Cons: Expensive to design and build. Most effective with equal movements on all arms. Could result in rear shunt collisions or side impact if drivers fail to give way. Possible collisions with the roundabout.
• Signal control at Black Park Road
Pros: Positive control of the junction Retains all turning movements May allow controlled ‘U’ turns. May control speed by physically stopping vehicles. Could incorporate a pedestrian facility. Similar junctions on the route in close proximity.
Cons: Expensive to design and install. May require speed limit reduction, with cons as previously given. May introduce other types of collisions (side impact, junction / signal overshoots, red light jumping, rear shunts). Southbound approach visibility may need improving.
• Lane drop to a single lane by road markings (hatching)
Pros: Speeds reduced through the junction. Retains all turning movements and vehicles are turning across one line of vehicles. Low cost depending on the length of the scheme.
Cons: Reduced capacity on the route May lead to queuing at peak times. May require speed limit reduction, with cons as previously given. May introduce other types of collisions (rear shunts, side swipe). Non-compliance of the hatching. Could facilitate and increase ‘U’ turns at the junction.
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• Central barrier.
Pros: Prevents crossover collisions.
Cons: Whole route may be necessary, or selected areas. Expensive to install Few crossover collisions reported. Maintenance liability. Vehicles that could have come to rest on central reserve may be deflected back onto the carriageway into the path of following vehicles.
The cost of each measure, or combination of measures, cannot be estimated until a full study is made. The above measures range from a speed limit reduction at around £15000 to full junction re design / roundabout at nearer £500,000.
Driver Demographics.
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Vehicle Drivers: 20 worst postcodes last 5 years
6
5
4
3
2
1
0 SL12 SL25 SL21 SL00 SL22 UB82 HP51 UB94 UB54 SL14 SL16 NW69 W53 RM95 HP124 SL65 HA11 UB83 SL13 UB109
A tabulation of the driver postcodes of those involved in the collisions on the A412 (not necessarily to blame) over the last 15 and 5 years indicates that SL1. SL2, SL3 and UB8 feature the most. This is useful as it indicates some targeted education in conjunction with Slough BC; LB of Hillingdon and TVP may be worthwhile to highlight the dangers of excessive speed, alcohol.
SL1 Latitude: 51.51 degrees Longitude: -0.61 degrees Postal Town: Slough Easting: 496439 degrees Northing: 180151 degrees Grid Ref: SU964801 District: Slough (B) Ward: Chalvey
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SL2 Latitude: 51.53 degrees Longitude: -0.6 degrees Postal Town: Slough Easting: 494555 degrees Northing: 182112 degrees Grid Ref: SU945821 District: Slough (B) Ward: Britwell
SL3 Latitude: 51.49 degrees Longitude: -0.55 degrees Postal Town: Slough Easting: 500439 degrees Northing: 177907 degrees Grid Ref: TQ004779 District: Windsor and Maidenhead (B) Ward: Datchet
UB8 Latitude: 51.53 degrees Longitude: -0.47 degrees Postal Town: Uxbridge Easting: 505732 degrees Northing: 182399 degrees Grid Ref: TQ057823 District: Hillingdon London Boro Ward: Uxbridge South
Summary.
• Between 01/01/2000 and 30/06/2016 there have been 172 reported injury collisions, of which, 7 were Fatal, 35 were Serious and 130 Slight.
• During this period collisions and casualties have reduced but 3 recent fatal collisions in the last 3 months, 2 at the junction with Black Park Road, have resulted in increased local concerns and a petition to install a roundabout.
• This section of the route is consistently high on the network safety team’s route list (ranked by the last 5 years KSI collisions per km). As a result many schemes have been carried out over the last 16 years.
• At 2 KSI collisions per km it would be 14 th on the annual Network Safety route list, ranked by KSI collisions per km.
• Most collisions are single vehicle loss of control or a right turning manoeuvre. There is a concentration of collisions at 3 sites along the route; Black Park Road, Wexham Park Lane and George Green. Wexham Park Lane has seen recent improvements and there is currently a scheme to improve the signals at George Green.
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• Black Park Road junction has seen the most collisions in the last 5 years (3 KSis and 8 slight) the majority (7) being right turn manoeuvres. It is also the junction subject of the petition and the site of 2 of the last 3 fatal collisions.
• Analysis of the collisions indicates that junction control would be a viable counter measure.
Recommendation.
• Long term; A bid is made to BCC to fund the feasibility, design and installation of traffic signals or a roundabout to control traffic and facilitate the turning movements. Signals would be consistent for the route and would involve less realignment of the road. However, the whole life cost of any measure would need to be considered prior to a final recommendation being made
• Short term; Explore and consider the lane drop or one right turn restriction. Consider other minor adjustments to include improved signing, lining, and contrasting surfacing at Black Park Road, together with possible education campaign with Slough BC.
Sue Brown, Peter Chapman, Naomi Povey. Network Safety Team Transport for Buckinghamshire [email protected]
3rd January 2017.
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Locations of Fatal collisions between 01/01/2000 and 30/06/2016
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Collisions reported in the last 5 years:
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Reported collisions in the last 3 years:
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