Application of Commercial Connected Vehicle Telematics Data to Evaluate Drivers' Behavior at the Onset of Yellow in a Signalized Corridor

This study integrates commercial connected vehicle (CV) telematics data with signal phase and timing (SPaT) information to analyze vehicular decision-making at the onset of yellow intervals at seven signalized intersections in Dubuque, Iowa. This research employs a novel approach by integrating signal phase data from traffic controllers with emerging CV data to identify Time to Yellow (TTY) information associated with each vehicle's journey and determine the stop-and-go decisions made by vehicles at the onset of yellow signals. Heatmaps were generated using the probability of stopping to visualize the dilemma zones and assess the outcomes for vehicles that decide to proceed, particularly regarding their ability to clear the intersection before the red clearance interval ends. The analysis explicitly highlights intersections 3, 4, and 6, indicating a need for further safety improvements (such as rumble strips or a yellow warning system) due to a higher incidence of vehicles failing to clear the intersection. The findings underscore the value of vehicle telematics information in monitoring dilemma zones in near real-time and informing advanced signal timing strategies, thereby enhancing our understanding of driver responses at intersections and potentially improving safety management.