Australia Road train

double-stacked trailers (with small truck , gooseneck dolly well) being unloaded @ timber creek, northern territory, australia

double (two-trailer) road train combinations allowed on roads in states of australia, including specified approaches ports , industrial areas of adelaide, south australia , perth, western australia. double road train should not confused b-double, allowed access of country , in major cities.

in south australia, b-triples 35.0 metres (114.8 ft) , two-trailer road trains 36.5 metres (120 ft) permitted travel on approved routes in north , west of state, including access adelaide s north-western suburban industrial , export areas such port adelaide, gillman , outer harbour via salisbury highway, port wakefield road , augusta highway.

triple (three-trailer) road trains operate in western new south wales, western queensland, south australia, western australia , northern territory, last 3 states allowing ab-quads (b double 2 additional trailers coupled behind). darwin capital city in world triples , quads allowed within 1 km (0.62 mi) of central business district (cbd).

strict regulations regarding licensing, registration, weights, , experience apply operators of road trains throughout australia.

road trains used transporting manner of materials: common examples livestock, fuel, mineral ores, , general freight. cost-effective transport has played significant part in economic development of remote areas; communities totally reliant on regular service.

the multiple dog-trailers unhooked, dollies removed , connected individually multiple trucks @ assembly yards when road train gets close populated areas.

when flat-top trailers of road train need transported empty, common practice stack them. commonly referred doubled-up or doubling-up . see illustration. sometimes, if many trailers required moved @ 1 time, triple-stacked, or tripled-up .

higher mass limits (hml) schemes piloting in jurisdictions in australia, allowing trucks carry additional weight.