Simulation and Real-World Testing of a Red Light Running Warning System and Estimated It Can Potentially Prevent About 7,700 Crashes Annually in Minnesota.
Minnesota Study Projected the Safety Benefits of Implementing a Red Light Running Warning System at 640 Intersections with Connected Vehicles.
Twin Cities, Minnesota, United States
Development and Demonstration of a Novel Red Light Running Warning System Using Connected V2I Technology
Summary Information
Red light running continues to pose challenges for intersection safety and is often linked to serious traffic accidents. This study focused on developing a Red Light Running Warning System (RLRWS) that alerts drivers in advance of a potential violation. The system uses connected vehicle (CV) technology, relying on either Dedicated Short-Range Communication (DSRC) or Cellular Vehicle to Everything (CV2X) to exchange real-time traffic data. Through Vehicle to Infrastructure (V2I) and Vehicle to Vehicle (V2V) communication, CVs receive critical information such as Signal Phase and Timing (SPaT), along with the speed and position of nearby vehicles. This information allows the system to assess current traffic conditions and predict future vehicle trajectories, estimating the likelihood of a red light violation. To enable these functions, communication equipment was installed to support V2I and V2V interactions. The RLRWS was evaluated through both simulation and real-world testing in Scott County, Minnesota between December 2023 and May 2024. Based on the findings, the study projected the system’s potential effectiveness if deployed at 640 intersections across the Twin Cities metropolitan area.
METHODOLOGY
This study developed a microsimulation testbed to validate RLRWS at a selected intersection, modifying the control logic in the model to allow target vehicles to run red lights. The RLRWS was then implemented at the intersection in real world using a roadside unit (RSU) and in a test vehicle equipped with an on-board unit (OBU).
The study estimated the safety impact of deploying RLRWS at 640 signalized intersections in the Twin Cities metro area, with 10 percent of the vehicles on the road being connected vehicles. The implementation of RLRWS requires equipment for every intersection and vehicle. Each signalized intersection must be equipped with a roadside unit (RSU), which is responsible for transmitting real-time signal information. Each vehicle must be fitted with an on-board unit (OBU), which serves two essential functions: 1) receiving data from the RSU, and 2) providing vehicle dynamics, such as speed, GPS coordinates, and acceleration, as inputs for the RLRWS algorithm. The RSUs and OBUs support standard V2X messaging formats to ensure seamless communication and compatibility. The warning signal is shown on the vehicle display screen to advise driver on how much braking is needed to avoid running the red light. Using the existing crash data, this study identified crash causes that can be avoided by the proposed RLRWS deployment.
FINDINGS
RLRWS deployment can reduce red light running behavior by up to 100 percent due to the system’s ability to warn drivers when running a red light. The study estimated that deploying the RLRWS could also reduce speeding-related and distraction-related crashes by at least 20 percent, and improper merging or turning crashes by 50 percent. Overall, the system could prevent around 7,700 crashes annually in the target area and save approximately $184,101,775. With an implementation cost of $66,426,650, this yields a benefit-cost ratio of 2.77.
