Modeling Road Network Capacity and Service Level under Variable Demand Pattern

To study the relationships among capacity, service level, and travel demand pattern of urban road networks, the concept of zonal reserve capacity is defined and adopted as an integrated measure index to road network performance. Mathematically, a bilevel programming model is formulated. The travel time requirements between origin–destination (OD) pairs are explicitly converted into capacity constraints of dummy links by modifying network representations. However, the presumption of fixed travel demand pattern among all OD pairs is eliminated in the proposed model. The trip distributions are determined by the Logit-type choice model according to OD travel times and trip attraction abilities of destination zones. Finally, a heuristic solution algorithm is presented, and a numerical example is shown. The numerical results further demonstrate the validity of the proposed model and algorithm.