Speed cameras reduce road traffic collisions and related deaths and injuries.  This conclusion comes from the world’s first systematic review on speed camera effectiveness, conducted by researchers at the University of the West of England and the University of Bristol and published in the British Medical Journal.

The review identified fourteen studies from around the world, all of which found that when speed cameras are introduced into an area, collisions, deaths and injuries are reduced. 

Collisions were reduced between 5% to 69%, injuries by 12% to 65%, and deaths by 17% to 71% in the immediate vicinity of camera sites.  The reductions over a wider area were of a similar order of magnitude. 

The review has however flagged up the limitations of the existing evidence and suggested  ways to improve the quality of the evidence around speed camera effectiveness. 

If possible, speed cameras should be evaluated using a Randomised Controlled Trial approach.  This would control for other factors that can affect the number of road traffic collisions in an area.  Comparable sites or areas could be randomly selected to receive cameras or not.  After a given time, changes in collisions, deaths and injuries in areas with and without cameras could then be compared.  An alternative would be to carry out any introduction of speed cameras in a phased manner, over a few years with careful collection of data, hence producing a natural comparison group. 

“This review shows that speed cameras are an effective road safety device,” said Paul Pilkington, Lecturer in Public Health at the University of the West of England.  “When speed cameras are introduced into an area, we see collisions, deaths and injuries fall. ”

“However, the quality of research evidence is not very high” cautions Sanjay Kinra, the report’s co-author from the University of Bristol. “We have suggested ways in which the evidence could be made clearer by careful data collection. It is imperative that the authorities introducing new speed cameras carefully consider our suggestions. Otherwise, these opportunities will be lost and we may never be completely certain”.