Official Title: Collision Statistics for Red Light Cameras
Author: Stella Madsen and D. Calam
This is a 2006 report by the city of Regina, Saskatchewan, Canada on the effects of red-light and speed cameras in the city of Regina. This study compares the before and after crash statistics of 3 RLC intersections in that city. The study uses 48 months of pre-RLC crash data compared to 48 months of post-RLC data. The statistics used in this analysis are from the Regina Police Department and the report does not defined a set Distance-From-Intersection inclusion zone for crashes. There are no data or conclusions in this report that suggest a reduction or increase in fatalities due to RLCs. The results show that crashes at RLC-equipped intersections have increased by 12% and injury crashes have increased almost 8% after RLCs were installed. The study concludes that: "Red Light Cameras can have a significant impact on traffic collisions.", and "At the Lewvan Drive and Dewdney Avenue intersection, rear-end collision increased significantly causing the overall total number of collisions to increase. The increase in traffic volumes(50%) and the higher speed limit on Lewvan Drive are likely the reason for this change."
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This is a basic 6 page report, the data and statistical analysis appear valid. One slightly diminishing factor is that there is a one month gap between the pre and post RLC periods, which is something that is rare in these kind of studies, although the very long pre and post RLC periods are far above average for a study like this and add to the validity of this report. The selection of 3 RLC intersections is a far below-average number of intersections for this kind of study and somewhat diminishes the validity of the report. The report uses no control intersections to help validate the data, or their assertion that the increase in crashes is caused by traffic increases. Some of the conclusions are supported by the supplied data.