Western Australian Current Regulations Western Australian Current Regulations (1) The performance of
the service, secondary and parking brake systems of a trailer used in a
B‑double or road train must comply with second edition ADR 38 or
third edition ADR 38 if the trailer would not otherwise be required to
comply with an ADR about braking.
(2) A road train
trailer to which subregulation (1) applies need not be fitted with a
mechanical parking brake if it carries wheel chocks that provide a performance
equal to the performance standard required for a parking brake system.
(3) A
semi‑trailer, regardless of when it was built, must have an
anti‑lock braking system that complies with third edition
ADR 38/01, if —
(a) it
is being used in a B‑double that includes a road tank vehicle, whether
or not the semi‑trailer is itself a road tank vehicle; and
(b) the
road tank vehicle is carrying dangerous goods.