Toward an evaluation framework for road pricing

Recent advances in road pricing technology and the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, which authorized $25,000,000 to fund congestion pricing demonstration projects, have created a resurgence of interest in the topic of road pricing, particularly in the form known as congestion pricing. However, review of the considerable literature on this topic has shown very little discussion on the need to evaluate the congestion pricing demonstration projects. Responding to this need, this paper presents an evaluation framework that may guide the evaluation efforts for these demonstration projects. We formulated a three-dimensional evaluation taxonomy: road pricing strategies, impacted groups, and impacts. We then used the taxonomy as a framework to study the literature so as to highlight state-of-the-art evaluation approaches and available modeling tools as well as to identify those lacking. Despite the large body of work published in this area, it appears that a major effort is needed to streamline and, in some cases, calibrate existing models so they may be used for evaluation purposes.