On Traffic Equilibrium, Congestion Tolls, and the Allocation of Transportation Capacity in a Congested Urban Area

Abstract

In a continuous transportation model with a scalar velocity field, dependent on the ratio of traffic to transportation capacity, and with trips generated by a gravity or entropy hypothesis, the equilibrium traffic distribution is derived along with the optimal capacity distribution. Possible improvements by introducing congestion tolls are discussed. It is seen that capacity should be distributed in proportion to traffic, so that velocity of transfer is constant, trips go along straight lines, and traffic is minimized. This implies that capacity is concentrated to the central parts. Congestion tolls are superfluous when capacity is optimally allocated.