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Speed cameras' effectiveness questioned
JAMES GOFFIN
23 May 2005 18:17
Speed camera bosses in Norfolk today defended their efforts to cut road deaths despite new research that suggest doing nothing is as effective as installing one of the controversial roadside devices.
Engineers from Liverpool University looked at 149 roads around the country to compare the effects of speed cameras, road humps and chicanes.
Their study found that while road humps led to a 44pc fall in accidents in 30mph zones, speed cameras managed just half that reduction.
Dr Linda Mountain's team found that in some cases doing nothing would have been just as effective as installing speed cameras, thanks to a statistical anomaly known as “regression to mean”.
The phenomenon – acknowledged by the Department for Transport but not taken into account in their figures for accident reduction – occurs where a series of accidents happen in the same place by chance rather than because of the road design.
The blip would naturally be expected to even out over following years, but speed cameras are misleadingly given the credit for the improved safety record.
“Cameras tend to be used at locations with a high accident frequency. But if you do nothing, you would tend to have fewer accidents in a subsequent time period,” said Dr Mountain.
“Estimates of the effectiveness of the cameras are almost certainly overestimates if they don't take into account this statistical effect.”
Founder of the Safe Speed road safety campaign Paul Smith said: "It's a great relief to see the truth about speed camera policy failure gradually coming out.
“Britain's motorists have been fined, lied to and distracted for far too long. Speed cameras are a £700 million policy failure.
“Far from saving lives they have displaced genuine life saving road safety policies resulting in considerable loss of life."
But tonight a spokesman for the Norfolk Casualty Reduction Partnership, which runs the county's network of fixed and mobile speed cameras, said
the statistical quirk was not relevant to Norfolk.
“If there were only a few accidents it would have an effect, but we only put cameras where there is a significant accident record,” he said.
He added that it was not particular helpful to compare cameras to road humps or chicanes.
“You wouldn't want road humps at places like Grapes Hill. Norwich has a lot of speed humps, but they are all in housing estates.
“They are different measures for different types of road.”
According to Government research published last year, speed camera sites in Norfolk saw a 56pc drop in accidents causing death or serious injury, and Cambridgeshire a 21pc fall. Separate research for Suffolk found a 75pc drop.
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See that that I've emboldened? UNBELIEVABLE!
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