This paper describes a user interface for a future route guidance system presenting the direction of travel in the driver's field of sight. Road signs are provided in front of intersections, and road signs emit light whose flash timing differs with the direction of branching. The liquid crystal shutter is fixed on the vehicle's front windshield equipped with the route guidance system. The operation of the shutter is system-controlled so that only light from the light-emitting pattern corresponding to the travel direction obtained from route searching is perceived by a driver. Since a driver obtains the route guidance information through road signs, the proposed interface releases the risk inherent when the driver attempts to access an in-vehicle display while driving. An experiment to compare the road sign interface with in-vehicle and head-up displays that use directional arrows was conducted to evaluate driving performance, eye movement, and subjective preference.
Abstract