Does Travel Information Influence Commuter and Noncommuter Behavior?: Results from the San Francisco Bay Area TravInfo Project

Abstract

Improved information received from public and private advanced traveler information systems can help travelers make more informed decisions, shorten times spent in traffic congestion, and reduce anxiety and stress. The behavioral responses of automobile and transit commuters as well as those of noncommuters to travel information received from radio, television, and telephone are analyzed. The influence of information has seldom been studied in terms of these different users. The data were collected through a computer-aided telephone interview conducted in the San Francisco Bay Area ( n = 947). The study analyzes the impacts of socioeconomic, context, and information variables on individuals’ decisions to adjust travel before beginning their trips; given an adjustment, the frequency of trip changes; and the type of most recent trip changes in terms of route, departure time, or mode shifts. The statistical analysis involves estimation of probit models with and without sample selectivity and a multinomial logit model. The results of the study indicate that a sample selectivity model is more appropriate for understanding respondents’ frequency of trip changes only when members of a subset of the sample population change their trips. Travel time uncertainty and travel information received from the electronic media increase the pretrip adjustment propensity. Furthermore, information from the most widely available and accessed medium, the radio, is highly likely to result in behavioral adjustments. Noncommuters have a high receptivity to canceling their trips in response to travel information. This has important implications for congestion relief in transportation networks.