The study reported below investigated the influence of two different navigation tasks on the design of map displays: 1) route following and alternate route generation in an unfamiliar town. The study examined four different maps: 1) north-up, 2) north-up-wedge, 3) track-up and 4) heading separated. The heading separated map was either north-up or south-up depending upon the orientation most compatible with a driver's current heading. This was intended to provide the advantages of a track-up map while reducing the frequency with which the map orientation changed. An analysis of task-map coherence predicted the compatibility of the route following task with either the track-up map or the heading separated map. The analysis also predicted the compatibility of the alternate route generation task with the heading separated map relative to the track-up map. These predictions were tested using a simulation hosted on an engineering workstation. Convergent measures support the predicted advantages of the heading-separated map.