Every year, traffic accidents kill more than a million people and injure close to 50 million around the world. As tragic and needless as these deaths are, they’re expected to increase over time: By 2020, traffic crashes will be third in the world ranking of burden of disease, as measured in disability-adjusted life years.

Injury severity is directly related to vehicle speed: The faster a car or truck is traveling, the greater the injury to people inside and outside the vehicle. One of the most common methods to reduce car and truck velocity is the use of speed cameras. A 2010 metastudy by researchers from the University of Queensland, “Speed Cameras for the Prevention of Road Traffic Injuries and Deaths,” documents the findings from 35 different studies of speed cameras, 28 of which measured their effect on crashes.

The findings of the metastudy include:

• All 28 studies showed a decline in the number of crashes in areas where speed cameras were deployed.
• Speed cameras reduced crashes by 8% to 49%.
• Speed cameras reduced fatal and serious injury crashes by 11% to 44%.
• The relative average speed reduction was 1% to 15%.
• Cameras reduced the proportion of speeding vehicles by 14% to 65%.
• Studies of longer duration showed that positive trends were maintained or improved with time.

All studies reported positive reductions in speed and crashes, implying that speed cameras are beneficial in reducing road traffic injuries and deaths. The authors suggest that future research look at the use of speed cameras in developing countries to compare their effects in different settings.

Tags: cars, metastudy, safety, technology

By Leighton W. Klein | November 29, 2010