Average speed cameras (ASC) have been hailed as revolutionary – avoiding the problems of distraction and sudden braking associated with fixed/mobile cameras.  But the Highways Agency's report “Safety Camera Technology at Roadworks – Final Report, March 2008”, concedes that several hazards are created by the deployment of ASCs:

·         Sudden braking

·         Distraction

·         Reduced headway (time between vehicles) - exacerbated by the sudden braking

·         Lane changing

The report also acknowledges that there are no proven safety benefits (collision/casualty reduction) and that driver education campaigns may become of increased importance to encourage “correct behaviour” in the presence of the cameras.

These conclusions are all the more surprising when you realise that the participants in this study were employees of the HA or the consultancy preparing the report (many subjective comments suggest that they are predisposed to the “potential benefits of speed cameras”).

The HA report can be downloaded from

http://www.ha-research.gov.uk/projects/index.php?id=1258

Safety engineering is guided by a number of principles, one of the most important being the order of precedence for methods to address hazards, as follows:

1. Eliminate the hazard.
2. Reduce the risk associated with the hazard or accident by implementing engineered mitigation strategies (eg. safety interlocks, such as the safety catch on a gun).
3. Reduce the risk associated with the hazard or accident by implementing mitigation strategies based on human factors (labelling, training or procedures).

In the case of ASCs, the source of the hazard is clear – it's the introduction of the cameras.  It is no more than wishful thinking that drivers can be educated to deal with that hazard - that is very poor, indeed culpable, safety engineering. 

As there is no safety argument for using the cameras, the first choice is to remove the cause of the hazard (i.e. take away the camera);  increased signage and driver education (as proposed by the report) to mitigate the hazard are covered by number 3 on the list and are therefore much less satisfactory and will never be as beneficial as eliminating the source of the hazard.

A “safety device” that actually reduces road safety until drivers adjust to it is totally alien to all safety thinking and culture.

The HA report was comparing ASCs with fixed cameras, concluding that ASCs had fewer drawbacks.  I have explained above that there is no safety argument for the deployment of ASCs, and it therefore follows that no speed camera should be allowed to be deployed on our roads as it is clearly decreasing road safety.  Mobile cameras are worse than fixed cameras in this respect.