This chapter explores the route guidance information needs of familiar drivers based on limited empirical evidence from field tests with developmental Advanced Traveller Information Systems (ATIS). A central issue in the definition of future markets for ATIS systems is the willingness of drivers to pay for equipment and access to various information services. The desire of drivers to have more control over route planning, and particularly to use the ATIS as a source of information for their own route planning, was a clear outcome of ADVANCE. In guidance mode, the ATIS functions very similarly to recent prototypes such as ADVANCE and TravTek, where the driver specifies a destination, the computer plans the route based on static and dynamic information, and provides specific route guidance to that location. Building ATIS systems which, in addition to providing computer-planned routes, allow drivers to plan their own routes based on computer organized information, is likely to be important to the success of ATIS.