This paper presents results from a states preference survey developed specifically for the calibration of critical values of time (VOT). The objective of the study was to obtain a continuously-distributed maesure of the tradeoff points between toll cost and trip time for road freight transporters in France, this distribution then usable as input into a disaggregate assignment model capable of testing road-pricing scenarios. The critical values of time were calculated from states preference survey data for each individual, and the set of VOT was then estimated by a continuous distribution. It is shown empirically that the average value of time increases with trip distance, which in turn motivates to extend the VOT distribution to include, as a parameter, a continuous function of distance. This result is directly applicable to traffic assignment models.
Abstract