Effects of Bicycle Left-Turn Waiting Areas on Bicyclist and Motorist Behaviors at Signalized Intersections in China

In recent years, transportation professionals in China started to use bicycle left-turn waiting areas and lagging left-turn phases to decrease collisions at signalized intersections. To better understand the operational effects of bicycle left-turn waiting areas on signalized intersections, cross-sectional analysis was conducted to compare bicyclist and motorist behaviors for three scenarios during different signal phases, based on field data collected from 10 approaches at 8 signalized intersections. It was found that the introduction of bicycle left-turn waiting areas were accord with psychological states of bicyclists and 87.5% to 96.9% left-turn bicyclists preferred to utilize such design during on and off peak hours. Meanwhile, the existence of waiting areas encouraged bicyclists to be more aggressive in stopping much closer to the center of signalized intersections. Travelling speed of straight-ahead and right-turn motors were decelerated and accelerated respectively, especially during off peak hours, due to the change in distributions of bicycles stopping positions. These influences on bicyclist and motorist behaviors eventually altered the safety level of signalized intersections.