Analysis of Driving Behavior During Different Phase-Switching Modes Based on Field Data

In this study, drivers’ behavior near intersections was examined under two different signal phase-switching modes, namely green flashing mode and green countdown mode. Two typical at-grade intersections in Shanghai were selected for a case study. Video techniques were employed to obtain traffic data and capture drivers’ behaviors during the period of a signal switching from green to red. Both qualitative and quantitative analysis were conducted to identify drivers’ behaviors and adaptability, considering driver's psychology changes, red-light running maneuvers and speed characteristics. Compared to green countdown mode, green flashing mode results in lower rates of red- light running and rushing, a higher rate of stopping, a lower speed/acceleration dispersion rate, lower average operating speed, and smaller speed fluctuation. These indicate that green flashing mode could induce more conservative maneuvers and hence enhance overall safety, while green countdown mode could cause more aggressive driving behaviors since drivers exactly know the end point of a green light. The downside of green flashing mode could be associated with the increased risk of car- following cases, due to unexpected stops or sudden speed drop-down of leading vehicles at intersections. The efforts were made to enrich the research findings of traffic signal control, providing references for the compilation of relevant norms and specifications and providing the basic for further development of ITS.