Zones 1 and 2, as seen by the observer, are limited in their respective planes as follows: as regards height, by two horizontal planes which are 1 and 2 72 m respectively above the ground; as regards width, by two vertical planes which make an angle of 15č towards the front and rear respectively, and outside the vehicle by reference to the median plane of the vehicle, passing through the point (or points) of contacts of vertical planes which are parallel with the median longitudinal plane of the vehicle, and limiting the overall width of the vehicle.
