As part of the New Jersey Department of Transportation (NJDOT) Red Light Traffic Control Signal Monitoring Systems Pilot Program, intersections that have been equipped with red light running (RLR) detection technology have their data recorded and analyzed on an annual basis as the state evaluates the effectiveness of the pilot before allowing statewide deployments. The results below are based on either one or two years worth of data. Twenty-four sites have a full year of data analyzed in the report, while two of those sites have two years worth of data. Number, types and severity of crashes have been compared to their pre-deployment levels, as well as trends in the number of traffic citations issued for running red lights.
For all of the 24 intersections evaluated in the report, the crash related analysis was conducted as a comparison of pre-deployment and first year of deployment data. Citations figures are a comparison between the first month of citation issuance compared to the end of the evaluation period (month 12). A comparison between control intersections (one in each of the nine municipalities with RLR technology deployments) and equipped intersections was also conducted. For the two intersections with two full years of data, the comparisons are between the pre-deployment data and the end of the second year, as well as between the first year and the second year.
For the two intersections with two full years of data, the following statistics were observed:
|Change from Pre-deployment to end of 2nd year||Change from End of 1st year to end of 2nd year|
|Same direction crashes||-42%||+17%|
|Estimated Crash Severity||-$268,900||-$119,900|
|Citations Issued||-85% (From Month 1 to Month 24)||-39% (From Month 12 to Month 24)|
- Over the two year period, total crashes, right angle crashes, same direction (rear-end) crashes and crash severity all decreased.
- While there was an increase in same direction crashes between years one and two, the severity costs continued to decrease due to the reduction in right-angle crashes, which is one of the main objectives of using RLR technologies.
- Citations have seen a downward month-to-month trend since they began issuance for violations at these intersections.
- As noted by the author, while there is no expectation that the number of citations will drop to zero, the continued downward trend demonstrates that the citations are changing driver behavior at those intersections, which was the goal of the RLR deployment.
- The author additionally notes that the small sample size for the two year analysis is small and should not be generalized to all intersections until more data can be analyzed as the pilot program matures.
- There was an increase in total crashes of 0.9 percent, which was lower than the 1.3 percent increase in total crashes at the control intersections.
- Right-angle crashes at RLR equipped intersections decreased 15 percent, while control intersections remained unchanged.
- The RLR intersections saw a 20 percent increase in same-direction crashes compared to the 2.5 percent increase at the control intersections.
- Similar to the results for two years of data on citation issuance, there was a decreasing trend in the number of citations from month-to-month, resulting in a 50 percent decrease in the number of citations issued in Month 1 to Month 12.