Mendivil et al's (1) excellent paper demonstrates the cost-benefits to be derived from investment in speed cameras. It invokes that remarkable Achilles-heel accompanying mass motoring: the toleration of levels of preventable danger that are unacceptable in other transport modes (2).

Attitudes to speed-cameras may reflect the misplaced suspicion that motorists have long directed to the accuracy of their speedometers (3). In the UK, the initial attitude of a considerable section of the motoring public towards speed-cameras was hostile: Cameras were deliberately smashed in the context of a campaign which asserted that speed-cameras were no more than indirect taxation: a cash-cow for government. It was further asserted that overt placement of speed-cameras would lead to erratic speeds which would increase the number and severity of crashes. This problem could of course be alleviated by covert placing of speed- cameras, but this solution was no emollient; it would likely bring about greatly increased detection-rates (4)!

The attitude of the current UK government has unfortunately regressed during the economic downturn: a shift to local decision-making could lead to the reduction or elimination of speed-cameras in some areas. Mendivel et al make it clear that this is not an economically sensible path to follow.

The story of speed-cameras may come to follow the older story of breathalysers: the latter have steadily achieved acceptance by most motorists - but a substantial minority continue stubbornly to misbehave (5). In the meantime, a side-effect of such toleration of danger may be that measures to promote less intrusive and healthier modes of travel - cycling and walking both for full journeys and in conjunction with public transort - remain less effective than they might be in many jurisdictions.

REFERENCES

1. Mendivil J, Gancia-Altes A, Perez K, et al. Speed cameras in an urban setting: a cost-benefit analysis. Inj Prev 2011:10.1136/ip.2010.030882.

2. Reinhardt-Rutland A H. Attitudes to SUVs and "slam-door" rolling stock represent a paradox. BMJ 2005; 331:967.

3. Denton G G. The use made of the speedometer as an aid to driving. Ergonomics 1969;12:447-454.

4. Reinhardt-Rutland A H. Roadside speed-cameras: arguments for covert siting. Police J 2001;74:312-315.

5. Gunay R A, Haran I. Face-to-face interviews with motorists who admit to drink driving in rural Northern Ireland. Traffic Eng Control 2005;46:376-379.

Conflict of Interest:

None declared