Abstract
Little is known concerning the impacts of new information systems on road users' behaviour. In a field study two modes of a route guidance system have been compared with a conventional route map and a human copilot. Results of both systems usually lie between those for map and copilot. There were more navigation and orientation errors, and the routes driven were longer and took more time than under the copilot condition. Compared to the route map, however, both Man-Machine-Interaction (MMI-) concepts revealed their great potential and effectiveness in facilitating the orientation task. (A)