Road System Optimum Equilibrium Model Based on Mean-Excess Travel Time

In order to study the effects on traffic assignment of travelers' route choice behaviors under random perturbations, the mean-excess travel time (METT) was assumed to describe travelers' route choice criteria. According to the theory of marginal cost pricing, the calculation formula for marginal cost pricing was derived under stochastic supply and demand. Then, a traffic assignment system equilibrium model was built and formulated as an equivalent variational inequality,and a self-adaptive projection and contraction method was used to solve the model. The results of numerical experiments show that when the ratio of origin-destination (OD) demand coefficient was 1.0 and the ratio of degradation of link capacity was 0.5, the marginal cost toll of route 1, compared with those by use of mean travel time and travel time budget to choose paths, was increased by 11.27% and 3.58%, respectively. When the reliability of travel time was 0.9, the marginal cost toll of route 1 were found to be 20.22% and 4.30% higher than those using the mean travel time and travel time budget as a basis for route choice, respectively.