Optimizing Frequency of Bus Services in Mixed-Traffic Urban Streets

摘要

In this paper, a new analytical model is proposed to determine optimal frequency for urban bus transit under variable demand by explicitly considering the interaction between different vehicles in urban mixed traffic. The effect of road congestion on in-vehicle travel time associated with each mode is explicitly considered in the formulation of link performance function. The equilibrium flow of vehicle in mixed traffic and the passenger flow on the transit network are computed using multi-modal equilibrium assignment with respect to the frequency selected by Hooke-Jeeves algorithm; finally, the optimal frequency is found by repeating the process. A numerical example is given to illustrate the application of the model and algorithm. From the convergence test and sensitivity analysis, some important conclusions are drawn. The computational result proves that the proposed model is applicable in real aspects of bus network design in mixed traffic.