Abstract
In order to obtain road network capacity under specified service level, a bi-level programming model of network reserve capacity based on road service level restraint is built. In this model, the basic OD traffic demand multiplier is maximized with service level restraint in the upper problem and a stochastic user equilibrium assignment model is used in the lower model. A algorithm is proposed for this bi-level programming model. A numerical example on a small road network is presented to demonstrate the effectiveness of the model and algorithm, and it indicates a positive correlation between the threshold of road network service level and road network reserve capacity: the more serious the traffic congestion degree is, the larger the traffic demand multiplier will be.