Combined Model for Flow Assignment and Mode Split in Two-modes Traffic Network

In order to alleviate urban traffic problems such as congestion, air pollution, and shortage of fuel, it is necessary to develop public traffic system with priority. A fundamental requirement for bus priority policy is to develop transit flow assignment models in the multimode network. Travelers' choice behaviors, e.g., mode and route choice, are important in modeling transit network flows. This paper develops a combined model for modal split and flow assignment in two modes network to obtain the proportion of traffic demand shared by bus and private car while considering the interactions between these two modes. And then a heuristic algorithm is designed to solve the proposed model. At last, a numerical example is used to illustrate the application of the model and algorithm. The results show that the traffic demand of private cars will increase quickly in the congested network for the lower service level of buses.