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Official Title: Photo Enforcement Program Review
Author: Shannon Hunt, CGA, CFE City Auditor, Brian Whiteside, CA•CIA Deputy City Auditor, Bryan Mansky, MBA, CMA, CIA, Audit Manager, Jason Egert, CA•CIA, Senior Auditor
Summary: This is a 2006 audit report by the Winnipeg Audit Department that compares the crash rate at 12 of the Red-Light camera intersections in the city of Winnipeg, Manitoba, Canada. The analysis has two separate sets of data, using up to 12 months of pre-RLC crash data compared to up to 24 months of post-RLC data(with another 48 months of post-RLC data available in the MPI update). The statistics used in this analysis are from Manitoba Pubic Insurance(MPI) and the City of Winnipeg, neither of which define their Distance-from-intersection crash inclusion zone. There are no data or conclusions in this report that suggest a reduction or increase in fatalities due to RLCs. The MPI data in this report shows a 64% increase in injury crashes into the second year post-RLC as well as a 58% increase in total crashes. The report concludes that "Information gathered from two sources on the number of collisions at monitored intersections is not consistent and would lead to contradictory conclusions." The update confirms this conclusion again, and shows that the MPI(insurance data) shows increases in crashes while the city-supplied data shows decreases in crashes.Download the original 2006 Audit Report below (528k) Comments:
This is a 65 page audit report and the MPI crash data and statistical analysis are verifiable, the selection of 12 RLC intersection sites is somewhat below average as these studies go. The use of less than 12 months of pre-RLC crash data is less than optimal, while the use of 24 months of post-RLC data is adequate. The conclusions are supported by the data. Notes:
This report shows what a large discrepancy there can be between police-reported crashes and the real number of crashes at an intersection. There was also a 2010 analysis by the Tom Brodbeck of the Winnipeg Sun that also compares the crash rate at 12 Red-Light camera intersections in the city of Winnipeg. This analysis used at least 12 months of pre-RLC crash data compared to up to 72 months of post-RLC data. The statistics used in this analysis are from Manitoba Pubic Insurance(MPI), and the results show that crashes at RLC-equipped intersections have increased by 18%, and the crash rate was not trending down during the 6 years since RLCs were installed. |
