Offset optimization based on queue length constraint for saturated arterial intersections (Q1936040)

Summary: Offset optimization is of critical importance to a traffic control system, especially when spillovers appear. In order to avoid vehicle queue spillovers, an arterial offset optimization model is presented in saturated arterial intersections based on minimizing the queue length over the whole duration of the saturated traffic environment. The paper uses the shockwave theory to analyze the queue evolution process of the intersection approach under the saturated traffic environment. Then, through establishing and analyzing a functional relationship between offset and the maximum queue length per cycle, a mapping model of offset and maximum queue length is established in the saturated condition. The validity and sensitivity of this model were tested by the VISSIM simulation environment. Finally, results showed that when volumes ratios are 0.525-0.6, adjusting offset reasonably under the saturated condition could decrease the queue length and effectively improve the vehicle operating efficiency.