Speeding and road safety

We might naturally assume that speeding (exceeding the speed limit) is a major factor in accidents, but the official evidence shows that this is not the case. The vast majority of even the most serious accidents occur when motorists are travelling within the speed limit. The evidence presented here is from official reports and links are provided so you can check everything for yourself.

Summary for all of Great Britain:

• Less than 14% of fatal collisions involve a vehicle that was speeding.
• Less than 8% of KSI (Killed or Seriously Injured) collisions involve a vehicle that was speeding.
• Around 5% of all collisions involve a vehicle that was speeding.

Summary for vulnerable road users:

• 98.9% of accidents where child pedestrians were killed or injured involved motorists who 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.

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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 speeding?
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.

1.1 Introduction

In order to prevent collisions, we need to know why they occur. When a collision results in death or injury, the Police should attend the scene and investigate. The factors that may have contributed to the collision (up to 6) are recorded and sent to the DfT (Department for Transport). They add up the factors and publish the results online. Police don’t investigate all collisions, and they don’t always find suitable factors to assign when they do. The official 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 cameras within 10 years, speeding was not investigated nationally until 2005. These are the results to the end of the decade.

1.2 Results of police investigations (Data):

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1.3 The speed camera puzzle.

How can there be a 42% reduction at speed camera sites, if less than 8% involve a vehicle that was speeding? (Table 1.2)

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 largest official report (the 4YE) does show (if read very carefully) that the speed cameras did not cause the 42% reduction. So the first is true, but do Police also 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.” 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. This means that speeding (and other factors) will tend to be lower than the official figures.

1.4 Can Police ‘prove’ after a collision that a vehicle had been “exceeding the speed limit”?

Answer: they don’t have to. Obviously, if police had to “prove” every contributory factor, then very few would be reported and their investigations would be of little value.

Instructions on how Police are to report collisions are in the “STATS20” form (report). It states (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 investigating 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 may naturally pay particular attention to factors that can lead to prosecution, such as exceeding the speed limit, drink driving and mobile phone use. 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 given include all “very likely” and all “possible” factors.

In collisions where “exceeding the speed limit” was not reported, the officer at the scene formed the opinion that it was not “possible” that any vehicle had been “exceeding the speed limit”. As a result, the figures for “exceeding the speed limit” should be 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, we might expect to see large variations in the frequency of “exceeding speed limit” in different Police force areas or large variations year after year, but this is not the case. All reports seem to show remarkable consistency both over many years and in different areas (see contributory factors tables, pages “Country” and “English Regions”). For instance in Thames Valley (report), the percentages of collisions that involved speeding were very similar to the national average:

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

Unfortunately, probably not. Even in collisions where vehicles were speeding, they may include stolen cars, criminals, foreign drivers, foreign vehicles, drivers who have not registered their vehicles correctly, the emergency services, joy riders, illegal, illegible or cloned number plates etc. In such cases, speed cameras may have no beneficial effect. Collision investigations do not report which of the collisions that involved speeding might have been influenced by speed cameras.

Also, some of the collisions that involved speeding may have been caused by a driver under the influence of alcohol or other drugs. It seems unlikely that speed cameras would prevent drugged drivers 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 enforcement of speed limits, but is speeding a major factor? The answer is known, so why is this information not included in the publicity?

This Dft Think! report (report) lists the top 10 contributory factors assigned to drivers in collisions where child pedestrians were killed or injured. “Exceeding the speed limit” was not in the top 10 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 speeding (p3). Note: there were actually more children “impaired by alcohol” in these collisions than motorists who were speeding. Note also that “Travelling too fast for conditions” is defined as being within the speed limit.

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

Cyclists:

This study of collisions involving cyclists (TRL report) on roads in Britain finds (p48) that 5% of cyclist fatalities involved motorists “exceeding the speed limit”. Where there were serious or slight injuries to cyclists, “exceeding the speed limit” was not in the top 10 and was therefore a factor in 3% or less.

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

This Transport for London report (report) examined cyclists killed or injured in Greater London and found there were a total of 4,021 pedal cycles (p21) involved in collisions. In these collisions, 30 of the motorists (0.7%) had been “exceeding the speed limit” (p22). Interestingly, almost as many cyclists (24) were “exceeding the speed limit” as motorists. Note, it is not illegal for us as cyclists to exceed speed limits, but how fast can we cycle? Were those collisions in 20mph zones?

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

Pedestrians:

This Dft report (p15 Table 7 report) examines pedestrians in collisions with cars in GB.

• Of all pedestrians killed in collisions with cars, 94% of the drivers were not speeding.

Note: why publish 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 these are for Scotland (Data: 2005 2006 2007).

“Exceeding the speed limit” was a factor (or a possible factor) in 3.2% of pedestrian deaths each year on average in Scotland. Note, that’s all vehicles, not just cars. In 2008 they appear to have stopped publishing this information.

• 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?

• It’s very unlikely that the speed cameras could be in just the right location (even using a thousand of them).
• The data doesn’t include which of those collisions involved stolen cars, criminals, drunk drivers/pedestrians, joy riders, foreign drivers, vehicles not registered correctly or illegal / illegible or cloned number plates etc.
• Speed cameras may have negative side effects that could be larger than any benefit they provide (effects of cameras).

1.9 Motorcycles and mopeds:

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?

The Department for Transports in depth study (report) on motorcycle accidents 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 (report) investigates fatal motorcycle 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. They investigated 39 fatal motorcycle accidents over 7 years (36% of the total). 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.

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 there may also be significant negative side effects (effects of cameras).