Optimal tolls with a multiclass, bicriterion traffic network equilibrium

The feasibility of the so-called marginal-cost pricing principle for providing an anonymous link toll (uniform toll across all individuals) pattern in a network with multiple user classes is investigated. The social and spatial inequality issues caused by the anonymous tolling are also addressed. It was assumed that the classes of users differed from one another in unobservable ways: they placed different values on the same amount of money, and they perceived travel disutility in money or time units. These characteristics precluded the possibility of nonanonymous or discriminatory tolling. Specifically, answers to the following questions were sought. Was the bicriterion user equilibrium flow the same as the single-criterion (in time or monetary units) flow in the presence of road pricing? Did the marginal-cost pricing principle suggest an anonymous link toll pattern that could support the multiclass, bicriterion user equilibrium flow pattern as a system optimum? In addition, models for selecting the most equitable anonymous link toll pattern that could lead to a system optimum were derived