Safe Speed Forums

The public should be wary of claims of 'success' by the road safety industry regarding speed cameras – or 'safety cameras' as they prefer to call them, writes Malcolm Heymer, former highway engineer and traffic management adviser to the Association of British Drivers

When the Association of British Drivers (ABD) was formed in 1992, its founder members feared that the introduction of speed cameras would threaten the road safety culture that had given Britain the safest roads in the world. Events have shown those fears to be well founded.

The first cameras were installed where studies showed that high speeds had contributed to accidents. Subsequently, however, they became an automatic response to accident problems, regardless of their causes – a camera was often cheaper than an engineering solution. But the misuse of speed cameras really took off when the 'cost recovery' scheme was rolled out nationally in 2001. This enabled 'safety camera partnerships' to reclaim the costs of enforcement from the income raised by their cameras, which proliferated.

The cost recovery scheme incentivised empire building by the partnerships, which adopted the term 'safety camera' in an attempt to justify their activities. Creative accounting was used to increase the expenses reclaimed, and cameras were often sited where the most drivers could be caught exceeding the speed limit, rather than where accidents had occurred. Speeding penalties rocketed.

Allowing enforcement to be funded from fines was bound to lead to abuse, so the cost recovery scheme was terminated in 2007. But this did not mean the end for the camera partnerships, however, because they were still able to claim an annual grant from the Treasury.

Ever since cameras have been deployed in large numbers, the partnerships have claimed they have reduced accidents significantly. An evaluation of camera effectiveness, published in 2005, claimed a 42 per cent reduction in KSI (killed and seriously injured) casualties in the vicinity of cameras. Tucked away in an appendix to that report, however, is an evaluation of the 'regression-to-the-mean' effect (RTTM). Most cameras were installed after an upward blip in accident numbers, which would be expected to fall again to the long-term average, even without any action being taken. This is the RTTM effect, which was found to account for three-fifths of the headline claim!

In addition, there has been increasing under-reporting of non-fatal casualties in recent years, evidenced by comparison of official police figures with those from hospital admission records. With roughly 10 serious casualties to every fatality, the KSI trend is heavily influenced by the diminishing reporting of serious injuries. There is also the long-term trend of reducing road casualties. When all these factors are taken into account, the reduction due to cameras is small or non-existent.

While cameras have had little beneficial effect, even at camera sites, the fatality trend for Britain as a whole suggests they have been detrimental to road safety, as feared by the ABD's founder members.

From 1950 to 1995, the fatality rate per hundred billion vehicle-kilometres (which allows for fluctuating rates of traffic growth) fell at a remarkably consistent 7 per cent per year. The rate over the subsequent 11 years, the height of the speed camera era, fell to a third of that.

The adverse effects of cameras are not just the obvious ones, like a driver braking sharply on seeing a camera. Far more serious is the excessive focus on speed limit enforcement, which sends the subliminal message that rigidly observing speed limits is the key to being a safe driver. This is not the case – drivers must take responsibility for adjusting their speed to the conditions, sometimes slowing to well below the speed limit.

At the same time as cameras were proliferating, many speed limits were being lowered. International experience shows that speed limits should be set at the 85th percentile level – the speed that 85 per cent of drivers would not exceed anyway – to achieve maximum compliance, the smoothest traffic flow, the lowest spread of speeds and minimum accident frequency. Speed limits set below this level lead to poor compliance, bunching of traffic and frustration, resulting in more accidents.

Many speed cameras, both fixed and mobile, are deployed to catch people exceeding speed limits where they are unreasonably low and no danger is caused. Average speed cameras do nothing to stop drivers going too fast at danger spots, while forcing them to drive unnecessarily slowly elsewhere. The use of vehicle-activated signs, which flash a warning if drivers approach a hazard at too high a speed, are a much cheaper and more effective solution than speed cameras at genuine high-risk sites.

It is notable how quickly many local authorities have decided to reduce or abandon their use of speed cameras in the face of budget restraints, suggesting they were not convinced of their effectiveness anyway. The vested interests in the road safety 'industry' are predictably forecasting carnage on the roads, but there is no evidence to support this view. The ABD hopes that the demise of speed cameras will turn out to be a rare silver lining to the cloud of recession.