VELOCITY ANALYSIS OF LEFT TURN VEHICLES DURING GREEN COUNTDOWN SIGNALS AT SIGNALIZED INTERSECTIONS

In urban transportation network, signalized intersections are the crucial bottlenecks with complex traffic conditions, easily appearing the phenomenon of traffic congestion. It is important to identify vehicle operation characteristics for improving the efficiency and safety of signalized intersections. This study focuses on examining the velocity changes of left turn vehicles during green countdown signals. The results show that when approaching the stopline during the countdown signals, left turn vehicles are more likely to experience operation fluctuation of abrupt acceleration and deceleration in peak hours, and maintain a stable acceleration in off-peak hours. The differences of speed feature between peak and off-peak periods might be due to traffic flow characteristics and drivers' emotional states. The findings of this study can provide supporting evidence for improving road safety and traffic efficiency at signalized intersections.