Effectiveness of speed cameras in preventing road traffic collisions and related casualties: systematic review.
OBJECTIVE
To assess whether speed cameras reduce road traffic collisions and related casualties.


METHODS
Systematic review.


METHODS
Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials, Medline, Embase, Social Science Citation Index, TRANSPORT database, ZETOC, the internet (including websites of road safety and motoring organisations), and contact with key individuals and organisations.


METHODS
Road traffic collisions, injuries, and deaths.


METHODS
Controlled trials and observational studies assessing the impact of fixed or mobile speed cameras on any of the selected outcomes.


RESULTS
14 observational studies met the inclusion criteria; no randomised controlled trials were found. Most studies were before-after studies without controls (n = 8). All but one of the studies showed effectiveness of cameras up to three years or less after their introduction; one study showed sustained longer term effects (4.6 years after introduction). Reductions in outcomes across studies ranged from 5% to 69% for collisions, 12% to 65% for injuries, and 17% to 71% for deaths in the immediate vicinity of camera sites. The reductions over wider geographical areas were of a similar order of magnitude.


CONCLUSIONS
Existing research 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. Controlled introduction of speed cameras with careful data collection may offer improved evidence of their effectiveness in the future.
Pilkington
Paul
P
University of the West of England, Faculty of Health and Social Care, Bristol BS16 1DD. paul.pilkington@uwe.ac.uk
Kinra
Sanjay
S
D000056:Accident Prevention / Q000295:instrumentation*; D000063:Accidents, Traffic / Q000401:mortality / Q000517:prevention & control*; D006801:Humans; D010781:Photography; D011379:Prognosis; D012107:Research Design; D014947:Wounds and Injuries / Q000401:mortality / Q000517:prevention & control*