A combined modal split and stochastic assignment model for congested networks with motorized and non-motorized transport modes

In this paper, a network equilibrium model is proposed for the simultaneous prediction of mode choice and route choice in congested networks with motorized and non-motorized transport modes. In Hong Kong, motorized and non-motorized modes are competing travel alternatives, as the average trip length is relatively short due to highdensity development in urban areas. In addition, non-motorized modes such as walking usually serve as complements to motorized trips. For example, transit passengers have to walk in order to gain access to and egress from transit stops. In this paper, the transit and walking modes are representatives of motorized and nonmotorized transport modes respectively. The fundamental congestion effects of each mode and inter-modal 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. It is found that more refined estimates of travel times and network flows can be obtained using the proposed model.