Car drivers' compliance with route advice and willingness to choose socially desirable routes

This study describes the results of a stated choice experiment conducted to analyze route choice behavior of car drivers under influence of advice and feedback on environmental consequences of their trips. Framing of the route advice is varied in terms of goal of the agency providing the advice (system or individual optimality) and extent to which it is generic or tailored to the specific preferences of the person. The findings suggest that, under conditions of rich information about attributes of choice alternatives, advice is discarded when it is supposed to serve the driver’s own interests and information allows the individuals to evaluate outcomes independently, but is taken into account when it is said to serve traffic management objectives. In line with expectations, the impact of advice is larger when it is labeled as personal compared to when it is labeled as generic. An interesting finding is that the impact of advice on evaluations of route alternatives is not uniform across attributes. Whereas some attributes become suppressed in the evaluation, others become more salient. The study further provides evidence that travelers are willing to trade-off social objectives against individual-level objectives. The authors discuss the implications of these findings for the design and use of travel information systems as an instrument for traffic management and identify problems for future research.