Toll Patterns for Multiclass-User Transportation Networks

In this paper we apply the following general scheme to determine toll patterns for multiclass-user transportation networks: we modify the travel cost as perceived by the individual traveler by charging him a “toll.” Then we try to determine the toll pattern in such a way that the system-optimizing flow pattern becomes at the same time user-optimizing. We discuss two toll policies: (a) Tolls are collected on a link basis, (b) Tolls are collected on a path basis. The study shows that there is a degree of freedom in the path-toll collection policy. Alternative criteria are proposed for the exploitation of the degree of freedom such as: (i) that the tolls collected be nonnegative; (ii) that the personal cost of travelers, before and after the imposition of tolls, remains the same; (iii) that certain classes are treated discriminately in order to attain some social good.