The present invention provides a method and assembly which determines a route using a computer system, a map and a user operated sensing device. The map shows a geographic area and includes coded data that is indicative of the map and reference points on the map. The sensing device is operable to sense the coded data and generate indicating data relating to the map's identity and one or more of the reference points. The computer system is operable to identify a geographic location from the indicating data. The sensing device is positioned relative to the map to generate indicating data specifying a point on the route, and the indicating data is sent to the computer system for it to determine a route incorporating the specified point.