Variable message signs and radio traffic information: An integrated empirical analysis of drivers' route choice behaviour

In this paper we analyse the impact of both radio traffic information and variable message sign information on route choice behaviour. The empirical analysis is based on an extensive survey held among road users in the Amsterdam corridor in July 1994. The data is stemming from the EC DRIVE II project BATT. To analyse the factors that influence route choice behaviour, several types of discrete choice models (ordered probit, multiple legit and bivariate ordered probit) have been estimated. Bivariate models are needed to model the (endogenous) dependency of the use of radio traffic information and variable message sign information. The results confirm earlier findings that women are less likely to be influenced by traffic information. New is the finding that commuters are less likely to be influenced, and that the level of satisfaction with alternative routes is strongly related to the type and distance of the alternative road. The analysis also reveals that the impacts of radio traffic information and variable message sign information on route choice behaviour are very similar, and that route choice adaptations based on radio traffic information are positively related to route choice adaptations based on variable message sign information. An interesting issue is the willingness-to-pay for having in-vehicle dynamic traffic information. As expected, the willingness-to-pay is relatively large for male drivers on business trips. Another important new finding is that the results suggest that there is a positive correlation between the use of radio traffic information and variable message sign information.