Pages 35

Road traffic signs abound on our road systems. These range from the simple route deviation chevron markings to complex variable message signs. In progressing along a chosen route, drivers regularly update their knowledge of current route position by attending, and responding appropriately, to information in these signs as compared with some cognitive representation of the predetermined route. Somewhat similarly signs indicative of road conditions must be processed and appropriate driving action taken. With the implementation of in-vehicle navigational aids the function of these signs changes. It is proposed that future road systems may not need signs and the implications of this are considered.