Transport researchers have, in recent years, paid increasing attention to the prediction of drivers' response to new forms of information and guidance such as Variable Message Signs (VMS) and In-Car Navigation/Route Guidance Aids. Prominent among the tools used in this research are route-choice simulators designed primarily to explore the impact of information and guidance systems on driver route choice. They overcome, to a large extent, the difficulty, or in some cases impossibility, of gathering data on real-world response to systems that are not yet in widespread production or use. Also, compared to more conventional questionnaire techniques, they can give the subjects a more realistic impression of the consequences of their decisions. However, route-choice simulators are relatively expensive to develop, especially when compared to Stated Preference (SP) or Stated Intentions (SI) techniques and so the question arises: is the extra expense involved in using a route-choice simulator worthwhile? This paper compares data from two recent, matched, studies of drivers' response to VMS messages and other forms of guidance: the first used the VLADIMIR route-choice simulator, the second used an SI questionnaire designed to replicate the VLADIMIR exercise as closely as possible.
Abstract