Speed cameras do reduce accidents, say researchers

Sep 12, 2008

(PhysOrg.com) -- Scientists at the University of Liverpool have developed an accident prediction model which proves that speed cameras are effective in reducing the number of road traffic accidents by 20 per cent.

They claim that other assessment methods have exaggerated their effectiveness by failing to account for the phenomenon ‘regression-to-the-mean’ whereby extreme values on one observation will, for purely statistical reasons, probably give less extreme measurements on other occasions when they are observed.

Taking into account ‘regression-to-the-mean’ when evaluating the success of a speed camera allows for the fact that the camera could genuinely be responsible for a reduction in accidents or that a run of bad luck on that road has just come to an end.

Dr Linda Mountain, from the University’s Department of Engineering, explains: “Although some parts of the road network are undoubtedly more dangerous than others, there is also a degree of randomness in where accidents occur – driver error, bad luck etc. – which means that an accident can happen anywhere. The obvious way to work out the true effects of cameras through a control group has been avoided because it involves deliberately leaving sites that would benefit from a camera with no equipment (or any other type of road safety scheme) which could cost lives.

“We used an alternative method for our analysis called Empirical Bayes. This takes into account uncertainty and predicts the mean number of accidents given what is known about the site – for example the type of road and the level of traffic on it. Our study looking at road accidents before and after the cameras were installed showed a fall in accidents of 19% allowing for regression-to-the-mean compared with a fall of 50% if the phenomenon had not been allowed for.”

She added: “Accident prediction models are essential to reliably evaluate the effectiveness of road safety measures and alternative design options.”

Provided by University of Liverpool

Explore further: Can science eliminate extreme poverty?

add to favorites email to friend print save as pdf

Related Stories

Ground Control to Major Tom: London ISA Catches Speeders

May 11, 2009

An Intelligent Speed Adaption (ISA) system is being tested by the London for Transport (TfL). The eye-in-the-sky ISA system relies on a computer installed in the vehicle with pre-loaded speed limit road data ...

Audi plans next-level tech for smarter driving

Apr 19, 2013

(Phys.org) —Audi, along with several U.S. universities, has been studying what contributes to road accidents, what can avert accidents, and the right technology systems that can keep drivers on track. According ...

Ford explores call turnoffs for stressed-out drivers

Jun 28, 2012

(Phys.org) -- No calls for you. That is the word from a new technology experiment by Ford, for stressed-out drivers who risk accidents by distractions from incoming calls, playing music, and other vehicle ...

Recommended for you

Can science eliminate extreme poverty?

3 hours ago

Science has often come to the rescue when it comes to the world's big problems, be it the Green Revolution that helped avoid mass starvation or the small pox vaccine that eradicated the disease. There is ...

Japan stem cell body splashes cash on luxury furniture

Apr 14, 2014

A publicly-funded research institute in Japan, already embattled after accusing one of its own stem cell scientists of faking data, has spent tens of thousands of dollars on designer Italian furniture, reportedly to use up ...

User comments : 0

More news stories

Progress in the fight against quantum dissipation

(Phys.org) —Scientists at Yale have confirmed a 50-year-old, previously untested theoretical prediction in physics and improved the energy storage time of a quantum switch by several orders of magnitude. ...