(1)  A light motor vehicle must have only –

(a) one axle group, or single axle, towards the front of the vehicle; and

(b) one axle group, or single axle, towards the rear of the vehicle.

(2)  A light trailer must have only –

(a) one axle group or single axle; or

(b) 2 axle groups, 2 single axles, or one axle group and single axle, in the following configuration:

(i) one axle group, or single axle, towards the front of the vehicle, with all the wheels on the axle group or single axle connected to the steering mechanism for that part of the trailer;

(ii) one axle group, or single axle, towards the rear of the vehicle.

(3)  A light semi-trailer that is extendible, or is fitted with sliding axles, must –

(a) have a securing device that –

(i) can securely fix the extendible part or sliding axles to the rest of the vehicle in any position of adjustment provided; and

(ii) is located in a position that can prevent accidental or inadvertent release, if the device is mounted on the chassis of the vehicle; and

(iii) is fitted with a visible or audible warning system to indicate to a person standing beside the vehicle that the device is not engaged; and

(iv) is fitted with a way of preventing loss of air from the air brake supply, if the device uses air from the brake system and fails in a way which allows air to escape; and

(v) is held in the applied position by direct mechanical action without the intervention of an electric, hydraulic or pneumatic device; and

(b) be built so that the adjustable parts of the vehicle remain connected if the securing device fails.