Study Details

Study Title: Safety Evaluation of Red Light Camera and Intersection Speed Camera Programs in Alberta

Authors: Izadpanah et al.

Publication Date: JAN, 2015

Abstract: Intersection related crashes constitute more than 20 percent of fatal crashes in the US. Red light running and high speed have been reported as contributing factors for severe crashes at signalized intersections that can be mitigated by using a system of automated enforcement. Red light cameras (RLC) have been deployed by many jurisdictions in the world. Unlike the RLCs, intersection speed cameras (ISC) have not commonly been used. RLCs have been evaluated by a number of researches; however, few studies quantified spillover effects in evaluating the effectiveness of RLCs. Additionally, little research has been conducted in evaluating the effectiveness of ISCs. In this study, data from various jurisdictions in the Province of Alberta in Canada were used to evaluate the effectiveness of both RLCs and ISCs with special emphasis on spillover effects for RLCs. Observational before and after studies were conducted using the empirical Bayes method to evaluate the changes in the intersections safety performance as a result of individual deployment of both RLCs and ISCs. Spillover effects for RLC intersections during the before period (before RLC activations) by considering a control group of unsignalized intersections were taken into account for before and after evaluation of RLCs. In addition, the magnitudes of spillover effects of the RLCs on all non-RLC signalized intersections (including RLCs during the before period) were also quantified. It was found that severe crashes decreased and property damage only crashes slightly increased for both RLCs and ISCs. Also, angle crashes significantly decreased (37.7% for RLCs and 31.3% for ISCs) and rear-end crashes increased (7.7% for RLCs and 9.4% for ISCs). In terms of spillover effect on all non-RLC signalized intersections, a significant drop in crashes (10.7% for Total, 6.6% for PDO, 22.7% Severe, 2.4% Angle, and 14.6% rear-end crashes) was noted.

Study Citation: Izadpanah, P., S. Thukral, H. Zarei, and A. Hadayeghi. "Safety Evaluation of Red Light Camera and Intersection Speed Camera Programs in Alberta". Presented at the 94th Annual Meeting of the Transportation Research Board, Paper No. 15-4704, Washington, D.C., (2015).


CMFs Associated With This Study

Category: Advanced technology and ITS

Countermeasure: Install automated speed camera at signalized intersection

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
1.01 -1 4 Stars All All Not specified Urban and suburban
1.11 -11 4 Stars All O Not specified Urban and suburban
0.68 32 4 Stars All K,A,B,C Not specified Urban and suburban
0.69 31 4 Stars Angle All Not specified Urban and suburban
1.09 -9 4 Stars Rear end All Not specified Urban and suburban

Countermeasure: Install red-light cameras

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.916 8.4 4 Stars All All Not specified Urban and suburban
1.014 -1.4 4 Stars All O Not specified Urban and suburban
0.676 32.4 4 Stars All K,A,B,C Not specified Urban and suburban
0.623 37.7 4 Stars Angle All Not specified Urban and suburban
1.077 -7.7 4 Stars Rear end All Not specified Urban and suburban