Combined Modal Split and Stochastic Assignment Model for Congested Networks with Motorized and Nonmotorized Transport Modes

Abstract

A network equilibrium model is proposed for the simultaneous prediction of mode choice and route choice in congested networks with motorized and nonmotorized transport modes. In Hong Kong, motorized and nonmotorized modes are competing travel alternatives, as the average trip length is relatively short because of high-density development in urban areas. In addition, nonmotorized modes such as walking usually serve as complements to motorized trips. For example, transit passengers have to walk to gain access to and egress from transit stops. Here, the transit and walking modes are representatives of motorized and nonmotorized transport modes, respectively. The fundamental congestion effects of each mode and intermodal interactions are taken into account in the simultaneous mode and route choice problem. An equivalent variational inequality (VI) problem is formulated to capture all the components of the proposed model in an integrated framework. A solution algorithm is presented for solving the VI problem. A numerical example is used to illustrate the application of the proposed model and solution algorithm. More refined estimates of travel times and network flows can be obtained with the proposed model.