What do systematic reviews say?

Quality of Life Manchester Short Assessment (MANSA) · patients with acute psychiatric disorders

On 80 km/h sections an 8% reduction of speeding vehicles seen on experimental sites compared to control sites in year 1, with a further 2% decrease in year 2. On 100 km/h stretches a 5% reduction in number of speeders seen in year 1, with a furthe...

Reduction in mean speeds by an average of 4.4 mph, 85% percentile speed reduction of 5.9 mph and a 35% reduction in percentage over the speed limit. These reductions were comparable for all monitored lengths e.g. up to 250m, 500m and 1 km.

Aggregate changes in crashes showed an insignificant 19.7% reduction in all reported crashes with a 20.1% reduction in injury crashes and an 89.8% reduction in fatal crashes along camera segments.

A significant 11% reduction in total crashes outside of city. Estimated 31% reduction in fatal crashes.

Greatest crash reductions in areas within 2km of camera sites, with 31% (1100), 39% (2200), 19% (500) and 21% (1600) reductions estimated for hospitalisation, medically treated, other injury and non‐injury crashes respectively.

A significant 58% reduction in serious or fatal injury crashes.

An estimated 7% reduction in overall injuries, 10% reduction in serious injury, and a 13% reduction in fatal crashes was reported

A net reduction of 71.3 % (p = 0.064) in injury crashes up to and including 4 days after the presence of enforcement. A net reduction of 73.9% (p =0.045) on the day when a mix of overt/covert enforcement employed.

A 25% reduction in expected crash rate, 11% reduction in injury crashes and a 17% reduction in daytime crash fatalities.

A reduction of 16% (+/‐ 7%) in expected crashes along study corridor. A 2.8km/h reduction in mean speed at monitoring site.

A 22% reduction in injurious crashes in first year and 20% in second year post intervention compared to before.

A non‐significant 19% reduction in crashes (not defined) A 20% reduction in injury crashes 2 years post intervention

After accounting for all potential confounders, the overall average effect of speed cameras on crashes was a reduction of 25% in personal injury crashes (PIA's) and an average 11% reduction in fatal and serious crashes for the 500m monitoring leng...

At camera sites a reduction of 19% for all crashes and a reduction of 44% for fatal and serious crashes. The authors state that the reduction in total crashes was significantly greater than that expected from the effect of RTM in 12 out of the 20 ...

Main findings= 5.8km/h reduction in mean speeds at 24 months at camera sites. For percentage exceeding speed limit, a 70% reduction at camera sites and a 20.9% reduction downstream at 12 months. These reductions were maintained at 24 months. For p...

A significant 56% reduction in fatal crashes relative to controls, a 12% reduction for all crashes and a 25% for serious crashes.

23% reduction in number of injury crashes. 66% reduction in fatal crashes.

Aggregate change in crashes was a significant 12% reduction for experimental roads.

A reduction of 35% in the total number of crashes for phase 1 and 2 compared to the control roads and the same period 3 years previously.