Route guidance systems in vehicles has started to use an oblique, slanted view of the map, mimicking something of the egocentric perspective the driver sees through the windscreen. Is this an effective strategy? What is the most effective map design to convey route guidance to drivers, and how can this be measured? In an experiment with four different modes of map displays the speed of decision making and accuracy of navigation have been tested. The four map types were: the traditional paper map, the north-up electronic map with position plotting (the symbol of the vehicle moving in the static map), the head-up electronic map (map moving, the position of the vehicle static and facing up) and the egocentric view map display, a 3-D scenery mimicking the world outside the wind screen. The experiment showed clearly that the egocentric 3-D view was the most effective.