Assessing Countermeasures Designed to Reduce Hazards Between Bike Lane Occupants and Right-Turning Automobiles in China

Abstract

Transportation professionals in China are facing challenges resulting from increased conflicts between various transportation modes in mixed traffic. This research examines practical and low-cost measures that could reduce the number of conflicts at intersections between bike lane occupants and right-turning vehicles, while maintaining or improving existing operational performance. To test different configurations, three representative intersections in Kunming, China, were analyzed using microsimulation software. The unique traffic flows and geometric layout of the intersections resulted in different alternatives being applied at each intersection. Changes included signal phase changes, such as delayed green signals and separate bicycle phasing; and geometric changes, such as the addition of turn lanes and upstream merge sections for conflicting traffic. Two main operational parameters are used to evaluate existing conditions and alternatives: delay and queue length. Each alternative was compared with the existing conditions to determine the impact on operations, while potentially reducing conflict. The addition of right-turn lanes, which displaces conflicts relative to other alternatives, yielded generally shorter queue lengths and delay, mostly because of added capacity. Partially protected through-bike signal phases proved to only slightly increase delay for most road users, and in some cases reduced delay, but could be more effective at reducing conflict than right-turn lane geometric strategies.