Microscopic Traffic Simulation Approach to the Capacity Impact Analysis of Weaving Sections for the Exclusive Bus Lanes on an Urban Expressway

This paper presents a microscopic traffic simulation approach to the capacity impact analysis of weaving sections caused by the installation of exclusive bus lanes (XBLs) on urban expressways. Three typical configurations of XBL in Beijing are identified, including median bus lane with off-on-ramp, curbside bus lane with on-off-ramp, and curbside bus lane with off-on-ramp. Then, the weaving section length, headway, mainline volume, as well as off-ramp and on-ramp volumes for general traffic are considered as parameters in designing simulation scenarios. Finally, the microscopic simulation is executed, by which the capacity of general traffic for weaving sections is estimated and the impact of the weaving section length and headway on the capacity is evaluated. It is found that the weaving section length and headway have different impacts on the capacity of general traffic in different configurations. The results also provide that the weaving section length and headway are more sensitive in the on-off-ramp than in the off-on-ramp scenario with the curb bus lane.