An evaluation of the attentional demand of selected visual route guidance systems

Experiments were conducted in a moderate-fidelity desktop simulator to investigate the attentional demand of four types of turn-by-turn route guidance displays. Subjects had to perform a tracking task with the mouse and record their decision to turn left, go straight, or turn right at an intersection, by pressing the left, middle or right mouse buttons. The RMS value of the tracking error and the response time to the pressing of the buttons, were the performance measures. Two of the turn-by-turn displays (one of which was text based, and the other that did not contain street names but merely a count of intersections to the turn) performed worse than the other two turn-by-turn displays. The most effective and preferred display was the one which used countdown bars to supplement text elements concerning distance from the turn location, retained turn location intersection geometry as part of the display, and provided symbolic cues when a turn was imminent