06 August 2007

Beware the DataMan

Watch out when your local politician wants to start raising revenue by authorizing unmanned traffic enforcement. They may come armed with buckets of worthless data to convince you they're right:
The case for speed cameras is reasonable, as far as it goes, but there is more to the issue. There are, for example, legitimate questions about whether speed cameras actually reduce the number of people killed and injured on area streets, and whether there are more cost-efficient ways of achieving the same or better results. There also is a major concern about whether speed cameras will ultimately function more as revenue-raising devices than effective tools for increasing road safety. Too little attention has been devoted to these and other issues in the region's public discussion on speed cameras.

By way of preliminary analysis, there is a paucity of credible data on the effectiveness of speed cameras in reducing traffic fatalities and injuries. In 2005, British researchers Paul Pilkington and Sanjay Kindra assessed 92 studies worldwide that claimed to provide credible data, but rejected all but 14 of them. Even among the 14 that met minimal standard criteria for methodological soundness, Pilkington and Kindra concluded: "Research conducted so far consistently shows that speed cameras are an effective intervention in reducing road traffic collisions and related casualties. The level of evidence is relatively poor, however, as most studies did not have satisfactory comparison groups or adequate control for potential confounders."

No comments: