Evaluation of Multi-Point Advance Detection Schemes for Dilemma Zone Protection

Abstract

As a solution to the safety issues caused by a dilemma zone, multi-point advance detection schemes are typically used at high-speed signalized intersections to provide dilemma zone protection. Among many multi-point advance detection schemes, the Winston-Salem configuration, the SSITE configuration, the Beirele configuration, and the Bonneson configuration are among the most widely used schemes in the United States. This paper aims at evaluating the four detection schemes with regards to their safety and operational performances using the state-of-the-art dynamical dilemma zone model, a dilemma zone hazard model, and VISSIM micro-simulation platform. Particularly, the calibrated Dilemma Conflict Potential (DCP) model was used to replace the traditional Number of Vehicles in Dilemma Zone as the surrogate safety performance measure. When coupled with the dynamical dilemma zone model, the DCP model provides a more accurate dilemma hazard estimation, which cannot be achieved via the traditional dilemma zone model and safety estimation methods. The evaluation revealed that the Bonneson Configuration is the safest scheme among the four evaluated schemes. However, the excellent safety performance is at the cost of relatively higher delays. Importantly, the evaluation results provide analytical information for practitioners in selecting the appropriate dilemma zone protection method for addressing safety issues at high-speed signalized intersections.