Ground clearance

Ground clearance of a vehicle is the minimum distance between the ground and the vehicle’s underside, other than its tyres, wheels, wheel hubs, brake backing plates, flexible mudguards and mudflaps.

A heavy vehicle must have a ground clearance of at least:

  1. at a point within 1m of an axle - 100mm; and
  2. at the midpoint between adjacent axles - one-thirtieth of the distance between the centre-line of each axle; and
  3. at any other point - the distance that allows the vehicle to pass over a peak in the road if the gradient on either side of the peak is 1:15.
Example of 1:15 gradient for the purpose of determining ground clearance.