(1) A vehicle must not be wider than 2·5 metres.
(2) For the purposes of subregulation (1), the width of a vehicle is measured disregarding the following—
(a) any rear vision mirrors, signalling devices and side-mounted lamps and reflectors;
(b) any anti-skid devices mounted on wheels, central tyre inflation systems and tyre pressure gauges;
(c) any permanently fixed webbing assembly-type devices, provided that the maximum distance across the body including any part of the devices does not exceed 2·55 metres.
Curtain-side devices are an example of permanently fixed webbing assembly-type devices.