The guidance system continually monitors the actual position of the vehicle, with the route to the required destination plotted as a sequence of consecutive path points defined by geographical coordinates and displayed to the driver as driving instructions. The actual location of the vehicle is determined by data or signals transmitted to the vehicle by radio, with continuous calculation of the straight-line distance to the next point on the planned route for comparison with a minimum value, for indicating deviation from the route if the obtained difference is greater than a threshold value.
