Thames Valley Speed Cameras

An independent report        

SPEEDING AND ROAD SAFETY

 

There are many claims about speeding and accidents, but what is the actual evidence?

 

This page contains the best evidence I can find regarding the involvement of speeding vehicles in accidents. All figures are taken from official published government reports (except for the Northern Ireland motorcycle report) and every figure can be verified by downloading the reports using the links provided. The information presented here has not been selected to promote any particular view, it is genuinely representative of the best evidence that I have found. If there is more accurate data, or data that challenges the figures given, please email me so that I can investigate further.

 

Terms:

 

Collisions      Road traffic accidents that result in fatal, serious or slight injuries, as recorded by Police

KSI               Killed or Seriously Injured. People who suffer fatal or serious injuries in collisions

Speeding      Exceeding the speed limit

 

Summary of findings for all of Great Britain:

 

  • 4.9% of all collisions involved a vehicle that was speeding

  • 7.4% of KSI collisions involved a vehicle that was speeding

  • 13.6% of fatal collisions involved a vehicle that was speeding

 

Summary of findings for collisions involving vulnerable road users:

 

  • Overall, 98.9% of child pedestrian injuries (killed or injured) occurred when motorists were not speeding.

 

  • Of all pedestrians killed in collisions with cars, the driver was not exceeding the speed limit in 94% of cases.

  • In Scotland, over 96% of pedestrian fatalities occurred when motorists were not speeding.

 

  • Overall, 95% of cyclist fatalities occurred when motorists were not speeding.

  • In Greater London, over 99% of collisions with cyclists occurred when motorists were not speeding.

 

  • All motorcyclists admitted speeding, yet over 96% of motorcycle accidents occurred when no-one was speeding.

  • In Northern Ireland, over 89% of motorcyclist fatalities occurred when the motorcyclists were not speeding.

1.3 The speed camera puzzle

 

If fewer than 8% of KSI collisions involve a vehicle exceeding a speed limit (Table 1.2) ...

... how can speed cameras reduce the number of KSI collisions by 42% (national report)?

 

Clearly something is wrong so there are 2 possibilities:

 

1) speed cameras are not causing those reductions.

2) the Police are under-reporting "exceeding the speed limit" as a contributory factor.

 

The governments Four Year Evaluation does show (if read VERY carefully) that the speed cameras did not cause the 42% reduction but do Police under-report speeding as a factor in collisions?

 

The contributory factors tables state: "Includes only accidents where a police officer attended the scene and in which a contributory factor was reported." Therefore all the collisions included in the tables above were investigated by the Police at the scene of the collision and the Police were confident enough in their conclusions that they officially reported the factors that contributed. The tables do not include collisions where Police did not attend or where they did not investigate or where they determined that no particular factor contributed so this may exaggerate all factors, including speeding (ie the real percentages are likely to be lower than shown in Tables 1.1, 1.2, and 1.3).

 

1.4 Can Police 'prove' after a collision that a vehicle had been "exceeding the speed limit"?

 

They don't have to. Obviously, if police had to "prove" every contributory factor, then very few would be reported and the results of their investigations would be of little value. The contributory factors form has been very well designed as it only requires the Police to give their "opinion", proof is not required. This should allow full reporting of all contributory factors.

 

The instructions on how police officers are to report collisions are on the main page (above) (download the STATS20 form).

 

This "STATS20" form states (p10): "The Contributory Factors are largely subjective and depend on the skill and experience of the investigating officer to reconstruct the events which led directly to the accident".

 

and (still p10): "The Contributory Factors reflect the Reporting Officer's opinion at the time of reporting and are not necessarily the result of extensive investigation. Furthermore, it is recognised that subsequent enquiries could lead to the reporting officer changing his opinion. This is not a problem."

 

This clearly states that the contributory factors are the "opinion" of the Police officer, proof is not required.

 

While slight injury accidents may not always be subject to "extensive investigation", serious injury accidents should be investigated more thoroughly and it could be expected that fatal accidents will be subject to "extensive investigation".

 

Also, Police officers will be aware of current road safety strategies and may therefore pay particular attention to factors such as exceeding the speed limit, drink driving, mobile phone use etc when investigating a collision. As a result, these particular factors would be unlikely to be overlooked. Furthermore, each "contributory factor" has 2 boxes, the first called "very likely" and the second called "possible" (p10). The figures quoted in all the tables on this page include all the "very likely" and all the "possible" factors. In collisions where "exceeding the speed limit" was not reported, the officer at the scene should have formed the opinion that it was not "possible" that any vehicle was "exceeding the speed limit". As a result, the figures for "exceeding the speed limit" should be around the maximum that occurred.

 

1.5 Can Police accurately determine after a collision whether a vehicle had been exceeding a speed limit?

 

If Police were not able to do this, then we might expect to see large variations in the frequency of "exceeding speed limit" in different Police force areas or for different time periods, but this is not the case. All reports seem to show remarkable consistency both over time (9 years of data so far) and in different areas (see 2009 tables above, pages "Country" and "English Regions"). For instance, in Thames Valley, the percentages of collisions that involved speeding were very similar to the national average:

 

Table 1.4

% speeding,

all casualties

% speeding, all collisions

Year

Thames Valley

National

2005

4.8%

5.0%

2006

5.7%

5.0%

2007

5.8%

5.5%

2008

5.7%

5.4%

2009

5.5%

5.2%

Average

5.5%

5.2%

Table 1.5

% speeding,

KSI casualties

% speeding,

KSIcollisions

Year

Thames Valley

National

2005

7.5%

7.7%

2006

6.8%

7.7%

2007

8.0%

8.3%

2008

8.5%

8.1%

2009

7.7%

7.9%

Average

7.7%

7.9%

 

 

 

 

 

 

 

 

 

 

 

Note: Thames Valley figures, Latest Casualty Statistics (p3 for area wide totals and p4 for exceeding speed limit).

Note: Thames Valley figures may be slightly higher than stated because Police may not have investigated every collision.

 

In over 92% of KSI collisions, the Police officers at the scene formed the opinion that all the road users involved were travelling at or within the speed limit, and that it wasn't really "possible" that any were "exceeding the speed limit".

 

1.6 Can speed cameras at least prevent around 8% of KSI collisions?

 

Unfortunately, probably not. Even in collisions where vehicles were exceeding the speed limit, many of these collisions may include stolen cars, criminals, the emergency services, joy riders, foreign drivers, foriegn vehicles, drivers who have not registered their vehicles correctly, illegal / illegible or cloned number plates etc and, in such circumstances, speed cameras may have little or no beneficial effect. Unfortunately, collision investigations do not separate from the collisions that involved speeding, those that may have been influenced by speed cameras.

 

Also, some of the collisions that involved a speeding vehicle may have been caused by a driver under the influence of alcohol. Would keeping drunk drivers within the speed limit prevent them from crashing?

 

1.7 How many children, cyclists and pedestrians are killed or injured by motorists who were speeding?

 

"If you hit a child when driving at:

  • 40mph, you will probably kill the child  

  • 30mph, the child has an 80% chance of survival

  • 20mph, the child is likely to survive with minor injuries"

 

This is often quoted to justify the rigid enforcement of speed limits, but is speeding a major factor in collisions where children are killed or injured? The answer to this question is known, so why is this information not included in the publicity?

 

This DfT report (Think!) lists the top 10 contributory factors assigned to drivers in all collisions where child pedestrians were killed or injured in 2009 and where the Police attended the scene, investigated and reported the factors that contributed. "Exceeding the speed limit" (speeding) was not one of the 10 top factors therefore speeding was 11th or lower. That means that, out of 6,244 injured children, there were fewer than 66 motorists (1.1%) who were travelling above the speed limit (p3). Note: there were actually more children "impaired by alcohol" in these collisions than motorists who were speeding.

 

  • Overall, 98.9% of child pedestrian injuries (killed or injured) occurred when motorists were not speeding.

 

And cyclists:

 

This study of collisions involving cyclists (TRL) on roads in Britain finds that 5% of cyclist fatalities involved motorists "exceeding the speed limit" (p48) during the 3 year period from 2005 to 2007. In collisions resulting in serious or slight injuries to cyclists, "exceeding the speed limit" was not in the top 10 and was therefore a factor in 3% or fewer.

 

  • Overall, 95% of cyclist fatalities occurred when motorists were not speeding.

 

This report on contributory factors (TfL) for cyclists killed or injured in Greater London in 2010 shows that there were a total of 4,021 pedal cycles (p21) involved in collisions. In these collisions, 30 of the motorists (0.75%) had been "exceeding the speed limit" (p22). Interestingly, almost as many cyclists (24) were "exceeding the speed limit" as motorists (30). Note, it is not illegal for us as cyclists to exceed speed limits, but how fast can we go? Were many of these collisions in 20mph zones?

 

  • In Greater London, over 99% of collisions with cyclists occurred when motorists were not speeding.

 

And all pedestrians:

 

This report (DfT) shows "exceeding the speed limit" as a factor in collisions with pedestrians in GB in 2005 (p15, Table 7):

 

   Injury ............. Total ..... Percentage involving "exceeding the speed limit"

  • Fatal ................ 333 ....................... 6%

  • Serious ........... 3,956 ....................... 2%

  • Slight ............ 13,627 ....................... 1%

 

  • Of all pedestrians killed in collisions with cars, the driver was not exceeding the speed limit in 94% of cases.

 

(note: why show figures only for cars? Would speeding be a lower factor for all vehicles?). I could not find contributory factors for pedestrian fatalities for all of Great Britain for other years, but figures for Scotland are published here:

 

In 2005 there were 65 pedestrians killed where 1 involved a vehicle exceeding the speed limit: ... Scotland2005_0041882
In 2006 there were 61 pedestrians killed where 3 involved a vehicle exceeding the speed limit: ... Scotland2006_0054406
In 2007 there were 60 pedestrians killed where 2 involved a vehicle exceeding the speed limit: ... Scotland2007_0078805
In 2008 they seem to have stopped publishing this information.

 

In Scotland in the only years for which figures have been published (2005-2007) there were an average of 2 pedestrians killed each year where "exceeding the speed limit" was a factor (or a possible factor). That's an average of 3% of all pedestrian fatalities in Scotland that involved vehicles speeding (that's all vehicles, not just cars).

 

  • In Scotland, over 96% of pedestrian fatalities occurred when motorists were not speeding.

 

1.8 If Scotland had a thousand speed cameras, could the lives of 2 pedestrians be saved each year?

 

1) The chances that the speed cameras would be in just the right location (even using a thousand of them) is very small

 

2) The data doesn't tell us whether those collisions involved stolen cars, criminals, the emergency services, joy riders, foreign drivers, drivers who have not registered their vehicles correctly or illegal / illegible or cloned number plates etc

 

3) The data doesn't say if the drivers were drunk and speed cameras may not prevent drunks killing pedestrians

 

4) Speed cameras may have negative side effects that could be larger than any benefit they provide (effects of cameras)

 

1.9 Motorcycles and mopeds make up less than 1% of vehicle traffic, but their riders suffer 14% of the total deaths and serious injuries on Britain's roads. Is this because motorcyclists exceed speed limits?

 

This in depth study on motorcycle accidents (DfT) states:

 

On p36: “Speeding was found to be common among the respondents, with 58% (n ¼ 143) admitting to always, or frequently, breaking the speed limit. The remaining respondents admitted to ‘occasionally’ breaking the speed limit but only when they thought it was safe to do so. Travelling in excess of the speed limit was considered to be a contributory factor in just 3.5% accidents on the motorcycle accident database”.

 

  • All motorcyclists admitted speeding, yet over 96% of motorcycle accidents occurred when no-one was speeding.

 

This report investigates fatal motorcyle accidents in Northern Ireland. It was produced by Right To Ride (so it's not an official government report) but I have not found a more detailed study than this. There were 39 fatal motorcycle accidents investigated (36% of the total in the 7 years from 2004 to 2010). Regarding speeding, the report states:

 

p3, "There were four cases (10.3%) of speeding, but in all cases, the actions of the other vehicle driver precipitated the collision."

 

  • In Northern Ireland, over 89% of motorcyclist fatalities occurred when the motorcyclists were not speeding.

 

1.10 An example of "spinning" the statistics

 

It has been claimed that: "SPEED IS A FACTOR IN 28% OF FATAL CRASHES". Where does this come from?

 

1) This means that the majority of fatal crashes (72%), do not involve "SPEED" as a factor

2) "SPEED" has a wide definition including excessive or inappropriate speed, much of which is within the speed limit

 

So how many fatal crashes actually involved a vehicle "exceeding the speed limit"? Fewer than 14% of fatal crashes that occurred in the last 9 years involved (or possibly involved) a vehicle exceeding the speed limit (Table 1.3).

 

In other words, in over 86% of fatal crashes, the opinion of the investigating officer at the scene of the collision was that it was not "possible" that the deaths involved a vehicle exceeding a speed limit.

 

  • In the final analysis, speed cameras may be attempting to solve a problem that is actually much smaller than we are being led to believe, and speed cameras may also have significant negative side effects.

Contents

 

1.1 Introduction

1.2 Results of police investigations

1.3 The speed camera puzzle

1.4 Can Police 'prove' after a collision that a vehicle had been "exceeding the speed limit"?

1.5 Can Police accurately determine after a collision whether a vehicle had been exceeding a speed limit?

1.6 Can speed cameras at least prevent around 8% of KSI collisions?

1.7 How many children, cyclists and pedestrians are killed or injured by motorists who were speeding?

1.8 If Scotland had a thousand speed cameras, could the lives of 2 pedestrians be saved each year?

1.9 Motorcycles and mopeds

1.10 An example of "spinning" the statistics

 

1.1 Introduction

 

In order to prevent collisions, the first step is to find out why they occur. When a collision results in someone being killed or injured, the Police should attend the scene and investigate why it occurred. All of the factors that may have contributed to the collision (up to 6) are entered into a contributory factors form. The DfT (Department for Transport) collects these forms, adds up the factors and publishes the overall results online. The Police don't investigate all collisions, and they don't always find suitable factors to assign when they do. The following information, therefore, only contains those collisions where the Police attended the scene, recorded the collision, investigated and assigned at least one contributory factor.

 

Despite the speed camera programme starting in 1993 and building to over 4,000 speed cameras by 2004, speeding was not investigated as a contributory factor nationally until 2005. Also, just because a factor occurred, does not mean it caused the collision nor does it mean the information could be used to prevent further collisions. The real causes of a collision are not simply what happened, they are what went wrong ie what was different to normal in any particular circumstance. On it's own, exceeding the speed limit may only be of limited use for collision prevention because we would also need to know what speed other motorists that didn't crash were travelling at. The contributory factors do not contain any speed survey data that may have been collected at collision locations.

 

1.2 Results of police investigations.

 

Contributory factors (downloaded from the DfT website) for 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 and 2013.

 

Contributory factors for all years are collated here: contributoryfactors.xls and the results for speeding are as follows:

 

Table 1.1
All collisions 2005 2006 2007 2008 2009 2010 2011 2012 2013 Average
Speeding (% of collisions) 5.0% 5.0% 5.5% 5.4% 5.1% 4.8% 4.7% 4.1% 4.4% 4.9%
Speeding (number of collisions) 7,314 7,258 7,725 7,103 6,594 5,836 5,576 4,745 4,753 6,323
All collisions investigated 147,509 145,798 140,361 131,582 128,185 120,827 118,403 114,696 108,934 128,477
.
Table 1.2
KSI collisions 2005 2006 2007 2008 2009 2010 2011 2012 2013 Average
Speeding (% of KSI collisions) 7.7% 7.7% 8.3% 8.1% 7.5% 7.1% 6.5% 6.2% 7.1% 7.4%
Speeding (number of KSI collisions) 1,832 1,900 1,993 1,833 1,622 1,400 1,308 1,214 1,309 1,601
All KSI collisions investigated 23,893 24,814 23,884 22,594 21,501 19,663 20,054 19,693 18,460 21,617
.
Table 1.3
Fatal collisions 2005 2006 2007 2008 2009 2010 2011 2012 2013 Average
Speeding (% of fatal collisions) 12.4% 14.1% 13.5% 14.4% 15.6% 13.6% 12.8% 11.6% 14.5% 13.6%
Speeding (number of fatal collisions) 325 381 342 313 301 221 213 173 216 276
All fatal collisions investigated 2,613 2,703 2,538 2,170 1,935 1,620 1,663 1,497 1,486 2,025