Northamptonshire Speed Cameras: Post Switch-Off Collision Analysis

This report, which looks at casualty stats at speed camera sites in Northamptonshire after the cameras were switched off, found no significant change in collision rates at the fixed camera sites post-switch-off compared to the collision trends seen elsewhere in the county.

The report’s author, Richard Owen from Road Safety Analysis, says this is “significant as many people would have expected a rise in collisions”.

The report looks at the four year period prior to the cameras being switched off (April 2007 to March 2011) and the four years after (April 2011 to March 2015).

In the period after the cameras were switched off, the findings highlight a 45% reduction in KSI at camera sites (29 to 16), compared to a 27% reduction across the rest of the county’s road network (1,628 to 1,193). In the same period, casualties of all types at camera sites were down 21% (from 90 to 71) while across Northamptonshire’s other roads there was a 29% fall (from 7,293 to 5,189).

The report concludes that “the changes between the two periods for Northamptonshire’s roads and the speed camera sites are not statistically significant”.

Richard Owen said: “The statistical analysis of the results show that there has been no significant change in collision rates at the fixed camera sites post-switch-off compared to the collision trends seen elsewhere in the county.

“This is significant as many people would have expected a rise in collisions if people started to ignore the presence of the cameras and increased speeds.

“The report does not look at speed survey data as this is not publicly available so it is impossible to say whether speed have changed at the sites, although anecdotal evidence suggests that people do indeed slow down for the cameras.

“The findings suggest that fixed cameras have a deterrence effect, regardless of whether they are operated, and this could be important information for other areas.”