Will a 20-metre combination make you more money?

An extra metre of combination length creates an equipment option. Whether it earns more money depends on the freight, the route and the cost of putting it to work.

The revised national rules that commenced on 1 August allow eligible combinations to operate up to 20 metres in the states and territories covered by the Heavy Vehicle National Law. The allowance is conditional: the combination must satisfy the applicable mass, dimension, braking and access requirements.

For a buyer, extra design room can help accommodate a longer prime mover or equipment without compromising the trailer layout. It does not automatically add payload or another pallet position.

Price the problem it solves

A volume-limited job and a mass-limited job need different comparisons. Extra space has little value if the truck already reaches its legal weight before filling the trailer.

Start with the existing task: usable freight per trip, trips per week, loading time and the routes and customer sites the combination must reach.

Then compare the proposed equipment’s purchase or modification cost, tare, axle distribution, maintenance and operating time. Where PBS is being used only to obtain extra length, an eligible prescriptive alternative may reduce approval work. PBS can still be worthwhile where its approved mass, design or access provides a stronger return.

Check the complete pairing

For combinations over 19 metres and no longer than 20 metres, heavy trailers need braking compliant with ADR 38/05 or later, powered by the towing vehicle. Semitrailers exceeding 9.5 metres from the front articulation point to the rear-overhang line also need compliant side-underrun protection.

Truck and trailer geometry need to be assessed together. A combination that fits the length envelope must still meet the other requirements, and switching trailers can change that result.

There is no universal payback figure. The worthwhile change is the one that produces a measured operating benefit greater than its additional cost.