Abstract: A personal GPS navigation device capable of simultaneously displaying a map, an indication of the current position of the device on the map and a GPS signal strength indicator. The device differs from the prior art in displaying a GPS signal strength indicator at the same time as the navigation map and hence does not require a user to leave the navigation mode to call up a separate GPS information screen in order to see the GPS signal strength. The GPS navigation device of this invention is further capable of displaying icons indication Points of Interest, whose display may be prioritised by type or by density of occurrence. The GPS of this invention is further able to calculate a speed of the device and use that speed to change the zoom of the map. The device is also able to change map zoom as the device approaches route situations requiring complex decisions.