The UK Department for Transport is commissioning a study of the possible negative side effects of photo enforcement. The research is expected to look into whether "the use of speed cameras causes a migration of accidents to other locations."

In addition, the Department wants to know whether the claimed reductions in accidents at speed camera sites comes from the "regression to the mean" phenomenon. This statistical effect describes what happens when a location experiences an unusually high number of accidents but naturally drops back to a normal level of accidents if nothing else is done. Since speed cameras are usually placed at such locations, it can appear as if the device caused the reduction in accidents.

At least one critic believes it is a little late for such research. Speed cameras have been used for more than 13 years and there are nearly 10,000 of the devices currently deployed throughout the country.

"It's good to see a move towards proper understanding of the issues surrounding speed cameras," said Paul Smith, founder of the Safe Speed road safety campaign. "But this is far too little and far too late. The research was required before the large scale introduction of speed cameras. Not only that but we shouldn't expect to see the results of this urgent research until 2008."