Studies Show Thames Valley Speed Cameras, An Independent Report
Special thanks to Jim for sharing this link with us!
http://www.speedcamerareport.co.uk/index.html
Thames Valley Speed Cameras, An Independent Report
http://www.speedcamerareport.co.uk/01_speeding.htm
SPEEDING AND ROAD SAFETY.
Last update: 29/Sept/2011
We hear a lot of claims about speeding (exceeding the speed limit) and accidents, so what are the facts?
In order to prevent collisions, we need to know why they occur. When a collision results in someone being killed or injured, the Police investigate and fill in a report form accompanied by a contributory factors form. The officers select from the supplied list of possible contributory factors those that may have contributed to each collision they investigate. The DfT collects these forms, adds up the factors and publishes the results online. Police don't investigate all collisions, and they don't always find suitable factors to assign when they do, so the following information contains only 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 by 2004, exceeding the speed limit was not investigated as a contributory factor by Police 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 other 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 were doing that didn't crash. The contributory factors do not contain any speed survey data that may have been taken at collision locations.
Results of police investigations can be downloaded from the DfT website: Road casualties in Great Britain. http://www2.dft.gov.uk/pgr/statistics/datatablespublications/accidents/casualtiesgbar/
2005 contributory factors: Road Casualties GB: 2005:
download "Contributory factors to road accidents (Excel 113 kb)" http://www.speedcamerareport.co.uk/contributoryfactors2005.xls
2006 contributory factors: Road Casualties GB: 2006 http://webarchive.nationalarchives.gov.uk/+/http://www.dft.gov.uk/pgr/statistics/datatablespublications/accidents/casualtiesgbar/roadcasualtiesgreatbritain2006
and download "Article 4 - Contributory factor statistics (Excel 229 kb)" http://www.speedcamerareport.co.uk/contributoryfactors2006.xls
2007 contributory factors: Road Casualties GB: 2007 http://www2.dft.gov.uk/pgr/statistics/datatablespublications/accidents/casualtiesgbar/roadcasualtiesgreatbritain20071.html
and download "Article 4 - Contributory factor statistics (Excel 243 kb)" http://www.speedcamerareport.co.uk/contributoryfactors2007.xls
2008 contributory factors: Road Casualties GB: 2008 http://www2.dft.gov.uk/pgr/statistics/datatablespublications/accidents/casualtiesgbar/rrcgb2008.html
and download "Article 4 - Contributory factors (Excel 378 kb)" http://www.speedcamerareport.co.uk/contributoryfactors2008.xls
2009 contributory factors: Road Casualties GB: 2009 http://www2.dft.gov.uk/pgr/statistics/datatablespublications/accidents/casualtiesgbar/rrcgb2009.html
and download "Article 4 - Contributory factors (Excel 378 kb)" http://www.speedcamerareport.co.uk/contributoryfactors2009.xls
2010 contributory factors: Road Casualties GB: 2010 http://www.dft.gov.uk/statistics?orderby=title&post_type=table&s=ras50 and download "RAS50001" http://www.speedcamerareport.co.uk/contributoryfactors2010.xls
Contributory factors for collisions from each year here contributoryfactors.xls (includes factors listed for PIA, FSC and fatal). http://www.speedcamerareport.co.uk/contributoryfactors.xls
Here is the puzzle:
If the police conclude that fewer than 8% of KSI collisions involved a vehicle exceeding a speed limit .....
..... how can speed cameras reduce the number of those KSI collisions by 42% (national average http://www.speedcamerareport.co.uk/03_government_reports.htm at camera sites)?
Clearly something is wrong so there are 2 possibilities:
1) cameras are not causing those reductions.
2) the police are under-reporting "exceeding the speed limit" as a contributory factor.
The governments 4-year evaluation report does show http://www.speedcamerareport.co.uk/03_government_reports.htm (if read VERY carefully) that the cameras did NOT cause the 42% reduction but do Police under-report?
The DfT spreadsheets 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 had contributed. The tables do not include collisions where Police did not attend 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).
Can Police 'prove' after the collision that a vehicle had been "exceeding the speed limit"?
Obviously if police had to "prove" every contributory factor, then very few would be reported and their investigations would be of little value. The contributory factors form has been very well designed such that the police officer is only requested to give his/her "opinion", proof is NOT required. This should ensure that no contributory factor will be under-reported.
The instructions on how police officers are to report accidents are on the main page http://www2.dft.gov.uk/pgr/statistics/datatablespublications/accidents/casualtiesgbar/ (above) (download the STATS20 form http://www.speedcamerareport.co.uk/stats20.pdf).
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.
Whilst slight injury accidents may not always be subject to "extensive investigation", we expect serious injury accidents to be investigated more thoroughly and we expect that fatal accidents WILL be subject to "extensive investigation".
Also every Police officer will be aware of the current road safety strategies and may 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 very unlikely to be "under-reported". Furthermore each "contributory factor" has 2 boxes, the first called "very likely" and the second called "possible" (p10). The figures quoted in the table above are the addition of all "very likely" factors and all "possible" factors therefore in all accidents where "exceeding the speed limit" was not reported, the opinion of the officer at the scene was that it was not even "possible" that any vehicle was "exceeding the speed limit".
As a result, the figures for "exceeding the speed limit" should be the maximum that occurred and these results are remarkably consistent both over time (6 years of data so far) and in different areas (see 2009 tables above, pages "Country" and "English Regions"). For instance, in Thames Valley, the percentage of KSI collisions (Killed or Seriously Injured) that may have involved a vehicle exceeding a speed limit was very similar to the national average:
year ....... Thames Valley ....... National
2005 ........... 7.5% ................. 7.7%
2006 ........... 6.8% ................. 7.7%
2007 ........... 8.0% ................. 8.3%
2008 ........... 8.5% ................. 8.1%
Average ...... 7.7% ................. 7.9%
And for all collisions (killed, seriously injured and slightly injured) which may have involved vehicles speeding:
year ....... Thames Valley ....... National
2005 ........... 4.8% ................. 5.0%
2006 ........... 5.7% ................. 5.0%
2007 ........... 5.8% ................. 5.5%
2008 ........... 5.7% ................. 5.4%
Average ...... 5.5% ................. 5.2%
Note: Thames Valley figures, Latest Casualty Statistics http://www.speedcamerareport.co.uk/tvsrp_sr09_02.pdf, 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 KSI collision.
We can see that in the vast majority (92%) of KSI collisions (Killed or Seriously Injured) the professional opinions of the police officers actually at the scenes was that they did NOT involve a vehicle exceeding a speed limit, not even "possible".
So can speed cameras at least prevent 7.8% 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, drivers who have not registered their vehicles correctly, illegal / illegible or cloned number plates etc and, in such circumstances, speed cameras may have little effect. Unfortunately the police reports do not separate out from the collisions that involved speeding, those that may have been influenced by cameras.
And many of the collisions that had exceeding the speed limit as a factor may have been caused by a driver under the influence of alcohol. Do speed cameras prevent drunk drivers from crashing? Are drunk drivers safe within the speed limit?
"If you hit a child when driving at http://www.saferroads.org/advice/drivers/speed/:, you will probably kill the child
40mph
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 why speed limits must be rigidly enforced, but is this why accidents occur? In other words, are pedestrians killed because vehicles are exceeding speed limits? The answer to this IS known, so why aren't we told? Why is this not publicised? This DfT report http://webarchive.nationalarchives.gov.uk/+/http://www.dft.gov.uk/adobepdf/162469/221412/221549/227755/contributoryfactorstoroadacc1802 states that exceeding the speed limit was recorded as a factor in pedestrian accidents in GB (P15, Table 7 http://www.speedcamerareport.co.uk/contributoryfactorstoroadacc1802.pdf):
..................... Total ..... Maximum percentage where speeding may have been a factor
Fatal ................333 ................. 6%
Serious ........... 3,956 ................ 2%
Slight ............ 13,627 ................ 1%
We can see that, of all pedestrians killed in collisions, the VAST majority (94%) did not involve any vehicle exceeding any speed limits. I cannot find contributory factors for pedestrian deaths for all of Great Britain for other years, but figures for Scotland are published here http://www.scotland.gov.uk/Topics/Statistics/Browse/Transport-Travel/TablesPublications/RoadAccidentsScotland:
In 2005 there were 65 pedestrians killed where 1 involved exceeding the speed limit: ... Scotland2005_0041882 http://www.speedcamerareport.co.uk/scotland2005_0041882.xls
In 2006 there were 61 pedestrians killed where 3 involved exceeding the speed limit: ... Scotland2006_0054406 http://www.speedcamerareport.co.uk/scotland2006_0054406.xls
In 2007 there were 60 pedestrians killed where 2 involved exceeding the speed limit: ... Scotland2007_0078805 http://www.speedcamerareport.co.uk/scotland2007_0078805.xls
In 2008 they seem to have stopped publishing this information.
We can see that in Scotland from 2005 to 2007, the only years for which figures have been published, there were an average of 2 pedestrians killed each year where "exceeding the speed limit" was a factor. That's an average of 3% of pedestrian deaths in Scotland involve speeding. Again we see that, of all pedestrians killed in Scotland, the VAST majority (over 96%) did not involve any vehicle exceeding any speed limits.
So, 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 tell us if the drivers were drunk and cameras may be unlikely to prevent drunks killing pedestrians.
4) Speed cameras may have negative side effects that are larger than any benefit they provide (effects of cameras).
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?
Report on mototcycle safety at DfT http://webarchive.nationalarchives.gov.uk/+/http://www.dft.gov.uk/pgr/roadsafety/research/behavioural/thirteenthseminar/motorcycleaccidentsprelimina4695?page=2 and download "In Depth Study of Motorcycle Accidents" http://www.speedcamerareport.co.uk/indepthstudyofmotorcycleacc.pdf .
On p35: “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 these Motorcyclists admitted to speeding, yet over 96% of motorcycle accidents were entirely within the speed limit.
An example of "spinning" the statistics:
Where does "SPEED IS A FACTOR IN 28% OF FATAL CRASHES" come from?
1) This means that the majority of fatal crashes (72%), have nothing to do with "SPEED".
2) "SPEED" has a wide definition that includes 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"? On average 13.9% of all fatal crashes that occurred in the last 6 years involved (or possibly involved) a vehicle exceeding the speed limit.
In other words, in over 86% of fatal crashes, the opinion of the investigating officer at the scene was that it was not even "possible" that the deaths involved a vehicle exceeding a speed limit. In the end, speed cameras may be attempting to solve a problem that is actually much smaller than we are being told, and may also have significant negative side effects. http://www.speedcamerareport.co.uk/10_effects_of_cameras.htm
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