At a recent meeting with the National Heavy Vehicle Regulator (NHVR) in early December, HVIA staff received an update on allowances for twin-steer heavy vehicles within the national regulations.
Historically, Australian Design Rules (ADRs) have set a limit on the spacing of twin steer axle centres to a maximum of two metres. There is no similar spacing requirement in United Nations nor European Union regulations, which required vehicles manufactured overseas to be modified specifically for Australia. That constraint increases their cost, and discourages market take-up.
That deficiency was proposed for rectification in the Federal Department of Infrastructure’s ‘Safer Freight Vehicles’ discussion paper in April 2021, and it was decided that it would be amended via ADR and Heavy Vehicle National Law (HVNL) reform.
The ADR review was completed in October 2024, and the maximum twin-steer axle spacing was increased to 2.5 metres in ADR 43/04. However, the HVNL review has taken longer, and as an interim measure, the NHVR has created a specific national notice for twin-steer vehicles to provide a regulatory means for them to access the road network.
The National Class 3 Euro VI Vehicle (wide-spaced twinsteer) Mass Exemption Notice and Operator’s Guide can be accessed here.
It is important to note that while all HVNL-signatory states have approved the notice, not all local council road managers have done so. This means that access arrangements for those twin-steer vehicles include all state-controlled roads, but vary between local councils. HVIA recommends reviewing the notice’s network.
The NHVR advised HVIA that its intent is for more local councils to be added to the notice until the HVNL is formally changed around mid-2026, at which point the notice will become defunct as twin-steer vehicles will be granted general network access, and a national notice will no longer be required.