Australian Dangerous Goods Code Edition 7.8 (Consignor and Transport Duties) 13.1.3.4: Detach trailers containing dangerous goods only at marshalling areas, depots, for immediate exchange, in an emergency or on breakdown

What does 13.1.3.4 require?

A trailer with dangerous goods on board may be uncoupled from a prime mover or combination only at a vehicle marshalling area that a local, state or territory authority has designated for loading and unloading, at a transport depot built for loading and unloading, for an immediate off-road swap of trailers with security maintained, in an emergency where uncoupling serves safety, or where the vehicle has broken down on a road.