Recent advances in road pricing technology and the Intermodal Surface
Transportation Efficiency Act (ISTEA) of 1991, which authorized $25,00
0,000 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 consider
able literature on this topic has shown very little discussion on the
need to evaluate the congestion pricing demonstration projects. Respon
ding to this need, this paper presents an evaluation framework that ma
y guide the evaluation efforts for these demonstration projects. We fo
rmulated a three-dimensional evaluation taxonomy: road pricing strateg
ies, impacted groups, and impacts. We then used the taxonomy as a fram
ework to study the literature so as to highlight state-of-the-art eval
uation 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 ca
ses, calibrate existing models so they may be used for evaluation purp
oses.