A route guidance system comprising an in-vehicle device (10) and a central route advisory system (30) in which the in-vehicle device comprises an audio emitter (18) and a visual display unit (24, 26) adapted to provide audio and visual instructions to a user to perform manoeuvres required to complete an optimal route, wherein the optimal route is transmitted by the central route advisory system (30) to the in-vehicle device (10) in response to a route request from the user to a human operator in the central route advisory system (30) to a specified destination.