Analytical Procedures for Estimating Capacity of Weaving Sections for the Median Exclusive Bus Lanes on an Urban Expressway

摘要

The installation of the exclusive bus lane (XBL) on an urban expressway will likely causemultiple turbulences of traffic flow in weaving sections near the exit/entrance, which exhibitsmore complexities than the configuration without an exclusive bus lane. However, ananalytical procedure for estimating the capacity of weaving sections for exclusive bus laneson an urban expressway is no existent. This paper attempts to present a micro-simulationapproach for developing the analytical procedure for the capacity of weaving sections with anexclusive bus lane. First, with a thorough analysis of the operation of weaving sections, threefactors that influence the capacity are identified. Then, a VISSIM based micro-simulationframework is developed. The regression analysis of factors influencing the capacity isconducted for the median XBL. Further, simulation experiments are designed. Finally, theanalytical model on the Capacity Reduction Factor (CRF ) is established, which considers theimpact of both roadway allocation from XBL and more complex weaving behavior due to theinstallation of XBL. A randomly chosen weaving section along the third ring road in Beijingwas used to validate the proposed model. Because there has not been an XBL installed on theexpressway ring road, a simulation model is developed for this chosen weaving section, inwhich the median XBL is installed and the capacity is calculated by the proposed model. Theresults are compared with those from the simulation model, demonstrating that capacitiesobtained from the proposed model are close to the simulated ones with small relative errors.Thus, the proposed model is shown to provide a reliable capacity estimation for weavingsections of the median exclusive bus lanes on an urban expressway.