Performance effects of landmark icons in route guidance displays

Advanced Traveler Information Systems (ATIS) are advanced communication and navigation systems that use computer-based in-vehicle systems to provide navigation and travel-related information to drivers. To help drivers navigate more effectively and get to their destinations more quickly and safely, it is very important that navigational information be effectively communicated to the driver. Landmarks are important environmental and navigational cues, and are important in helping drivers to get to their desired destinations. This study consisted of two experiments that investigated the effect of incorporating landmark icons in ATIS turn-by-turn displays to see if this could aid navigation performance. Experiment 1 was a pilot study to select the four building landmarks icons and the four traffic control device landmarks with the highest comprehension rate to incorporate in the ATIS display used in Experiment 2. The four building landmark icons selected for Experiment 2 included church, gas station, restaurant, and phone booth icons; the four traffic control device landmark icons selected were YIELD sign, NO U TURN sign, NO PARKING sign, and traffic signal light.; In Experiment 2, 48 participants drove a simulated route using an ATIS display that either had, or did not have, landmark icons. The simulated ATIS recommended which branch of a 4-way intersection to take in the simulated routes. Participants drove 6 routes of 12 intersections each. For each set of two routes, one was driven in a clear visibility condition and the other route was driven in a foggy visibility condition. Navigation dependent measures included navigation decision time, turning accuracy, and turn signal accuracy. The results indicated that both building and traffic control device landmark icons reduced decision time for both younger and older participants. However, the landmarks improved decision time more for older drivers than for the younger drivers. Both types of landmarks improved the turn signal accuracy and turn accuracy of older drivers, especially when driving in the fog.; These findings are discussed in relation to other research concerning the use of landmark icons in ATIS displays, and in relation to the use of ATIS navigation systems in general.