Organization Method of Asymmetric Two-Leg Displaced Left-Turn at Urban Intersection with Heavy Load

As the bottleneck of urban traffic, the intersection is the key to mitigating traffic congestion. Displaced left-turn (DLT) is a novel countermeasure that can effectively relieve the conflicts of the heavy traffic flows in different directions at the urban intersection by transferring them to the adjacent road sections, which is efficaciously able to improve traffic capacity, reduce delay, and lower traffic conflict point density. This paper takes the urban intersection with heavy traffic load as the research object, systematically expounds the characteristics and applicable conditions of DLT, and then builds the DLT dedicated lane length calculation model and the signal coordination control method, to propose the organization design of asymmetric two-leg DLT which is more flexible and adaptable than ordinary DLT. Then, the fuzzy comprehensive evaluation model based on the degree of Hamming closeness is used to evaluate its optimization effect. Finally, a case study using simulated data showed that the asymmetric two-leg DLT evidently effects relieving the serious traffic congestion, benefiting environment, and improving traffic safety.