The Effectiveness of Speed Cameras: A Review of Evidence

This report pulls together a range of analyses on the effectiveness of safety cameras, and some more recent data, to provide a considered and comprehensive assessment of their contribution to road safety.

The sources of information include the four-year camera evaluation report published in December 2005; related work by Mountain, Hirst and Maher; studies in London; national statistics on traffic speeds, collisions and casualties and international research on relations between them; and recent figures from road safety partnerships.

The key findings of this report are:
• Deployment of speed cameras leads to appreciable • reductions in speed
in the vicinity of the cameras and substantial reductions in collisions and
casualties there over and above the likely effects of regression to the mean.
• Reductions in collisions and casualties differ between fixed and mobile,
and between urban and rural camera sites. Judging from the evidence,
the operation of cameras at over 4,000 sites of all types resulted in around
1,000 fewer people being killed or seriously injured in the vicinity of
cameras in the year ending March 2004.
• National surveys indicate clear and sustained falls in the average speeds
of cars on 30 mph roads, and in the proportion of cars exceeding the limit,
which are likely to have contributed to concurrent reductions in collisions
and casualties on built-up roads.
• The evidence from a study in West London is that speed cameras led to a
reduction in casualties not only at camera sites, but across the wider road
network.
• Majority public acceptance of cameras was widespread at the height
of the national camera safety programme. Subsequent annual surveys
by the AA indicate that it has remained so, with three-quarters of those
questioned in October 2010 regarding the use of cameras as acceptable.
• Increases in speeds and speeding at various sites where cameras were
visibly out of action have been recorded over the years since 2004.
• Data for 2007-2009 supplied by a number of road safety partnerships,
while not covering the whole country, suggests that big falls in fatal or
serious casualties at camera sites have persisted over time.
• National decommissioning could result in about 800 extra people across
Great Britain being killed or seriously injured each year.
• In the year ending March 2004 the benefit/cost ratio of camera
enforcement was about 2.3. Data for 2006-07 shows the cost of camera
enforcement was being covered by penalties paid by detected offenders
with only a modest surplus to the Exchequer of less than £4 out of each
£60 penalty paid.