The National Transport Commission has flagged a review of Australian Road Rule 108, the national model provision governing truck and bus low gear sign compliance, following industry concerns about its application to zero-emission heavy vehicles.
The move comes after technical advocacy by the Heavy Vehicle Industry Australia at the February 2026 Vehicle Standards Consultative Forum in Canberra.
Australian Road Rule 108 requires that when a truck or bus travels on a road subject to a truck and bus low gear sign, the vehicle must be driven in a gear low enough to limit speed without the use of a primary brake.
While the intent is to ensure engine braking is used on steep descents, the wording presumes conventional transmissions and braking systems.
Battery-electric and fuel-cell trucks typically operate without multi-speed manual gearboxes and may not feature the conventional distinctions between primary and secondary braking. Instead, they rely on regenerative braking systems and integrated electronic control systems.
This creates a technical compliance gap, despite the vehicles meeting safety design standards.
Adam Ritzinger, Chief Technical Officer at HVIA, said the issue reflects broader regulatory challenges as vehicle technology evolves.
“This is a case of the road rules being outdated by advancing technology, which is something that the industry is grappling with, and will continue to grapple with as new innovations come to the market,” Ritzinger said.
“Two HVIA members raised it with me separately in 2025, and I put it on the agenda for the Vehicle Standards Consultative Forum in February 2026. HVIA is a member of that forum, and through it, has the chance to shape national regulations in a range of areas.”
The model Australian Road Rules form the template for state and territory road regulations, similar in structure to the Heavy Vehicle National Law. Each jurisdiction adopts and administers its own version.
Following discussion at the forum, the NTC prepared a policy document and is now seeking industry feedback until March 11, 2026.
The consultation is expected to explore whether the low-gear rule should be reframed to focus on speed-control outcomes rather than on mechanical gear selection, ensuring technology-neutral compliance.