28.—(1) Every part of every track of a track-laying vehicle which comes into contact with the road shall be flat and have a width of not less than 12.5 mm.
(2) The area of the track which is in contact with the road shall not at any time be less than 225 cm2 in respect of every 1000 kg of the total weight which is transferred to the road by the tracks.
(3) The tracks of a vehicle shall not have any defect which might damage the road or cause danger to any person on or in the vehicle or using the road, and shall be properly adjusted and maintained in good and efficient working order.