Brookhuis, K., University of Groningen, Netherlands
The first results of the European project TravelGuide (GRD1 - 1999 - 10041) indicate that the development in the field of traffic information provision seems to be in a kind of transition phase where more and more information is presented by in-vehicle systems. To meet the demands of traffic information system users, it seems therefore promising to concentrate on a method by which relevant and desired information can be presented to road users while at the same time avoiding to influence traffic safety in a negative way. This could be achieved through providing in-vehicle and roadside information in a concerted manner. A relatively new and unexplored area is the integration of in-vehicle systems and roadside information systems. On-trip information provision can be either in-vehicle or roadside based. In-vehicle systems are highly suitable for providing personalised traffic information. Roadside systems are in principle very useful for providing up-to-date traffic information to all road users, also those not equipped with in-vehicle systems. Integrating these two types up to a certain level is beneficial for both road users and road authorities. By making the two types of systems complementary, a selection can be made in what information should be presented on which system. For instance, road users can be provided with the most acute and important information by roadside information systems and additional information can be provided by means of in-vehicle systems, or alternatively, in-vehicle systems may be used for priming the drivers to oncoming roadside information.