Heavy vehicle modifications

Common and complex heavy vehicle modifications require approval by an Approved Vehicle Examiner (AVE) or the NHVR.

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This web page offers general guidance around modification classifications. For more detailed information, refer to the NHVR Code of Practice for the Approval of Heavy Vehicle Modifications (PDF, 433KB) (the NHVR Code) which sets out our framework for the approval of heavy vehicle modifications.

Minor modification

Minor modifications that don’t cause a vehicle to be non-compliant with heavy vehicle standards can be made without approval.

Acceptable changes generally include fitting optional equipment or making alterations that are within the manufacturer’s specifications.

Some examples of the limited type of modifications that can be classified as minor:

  • additional ADR-compliant lighting
  • aerials
  • air conditioning
  • alarm systems
  • plastic shields for lamps and windscreens
  • manufacturer’s wheel and tyre options (that do not affect the Gross Vehicle Mass (GVM) or Gross Combination Mass (GCM) rating of the vehicle).

Consider seeking advice from a vehicle modifier, an AVE or the NHVR regarding your minor modification.

Common modifications under the Code of Practice (Section 86 of the HVNL)

Common modifications that comply with the NHVR Code, may be authorised by an Approved Vehicle Examiner (AVE). These modifications must be performed and certified in accordance with the requirements of the National Code of Practice Vehicle Standards Bulletin (VSB 6) – Heavy Vehicle Modifications (VSB6) and do not require additional approval by the NHVR.

The NHVR Code applies the existing National Code of Practice Vehicle Standards Bulletin (VSB 6) – Heavy Vehicle Modifications - the national standard for the most common modifications made to heavy vehicles. The requirements in VSB6 are based on accepted vehicle engineering practices, heavy vehicle standards and modification recommendations from the original vehicle manufacturer (OEM).

Vehicles that are modified in line with VSB6 must maintain the vehicle’s compliance with heavy vehicle standards. If approved, the AVE will issue a modification certificate and ensure a modification plate is attached to the vehicle when it passes inspection.

In addition to VSB6, a standalone Queensland-only modification code, the Concessional Livestock Loading – Vehicle Rating is applied by the Code.

Modifications performed and certified in another jurisdiction

Modifications performed and approved in participating jurisdictions are recognised in all participating jurisdictions.

Modifications performed in a non-participating jurisdiction that comply with the requirements of VSB6, have been approved in accordance with local requirements and have a modification plate issued are recognised as approved modifications under the HVNL.

This means that approved modifications do not need to be re-certified when the vehicle is transferred to another jurisdiction.

Complex modifications outside of the Code of Practice (Section 87 of the HVNL)

Complex modifications are those that cannot be performed in accordance with VSB6 or may cause the vehicle to be non-compliant with a heavy vehicle standard. These modifications require approval by both the NHVR and an AVE.

Complex modifications are significant or extensive changes that can seriously affect the safety of the vehicle and its operation on the road, impacting the vehicle’s design, strength, structural integrity and handling characteristics.

Applications for heavy vehicle modifications are assessed by the NHVR and must be approved before the modification is carried out.

If a modification is approved, we will issue a Statement of Requirements that details how the vehicle modification should be undertaken and any related inspection requirements. Once the modifications are made, they need to be approved by an AVE who will issue a modification certificate and ensure a modification plate is attached to the vehicle if it passes inspection.

In addition, an engineering analysis (certification) may also be required depending on the extent of the modification and its potential impact on the vehicle’s safe operation.

Concessional Livestock Loading

The Concessional Livestock Loading – Vehicle Rating is used to determine the suitability of a vehicle for the carriage of livestock in Queensland.

The assessment ensures that manufacturer’s ratings are not exceeded when the vehicle is loaded with fuel, water, livestock, etc., and that weight is distributed appropriately.

Read Modification Code S10 - Concessional Livestock Loading – Vehicle Rating (PDF, 4.9 MB)

The Concessional Livestock Loading document should be read in conjunction with the current version of the Queensland Class 3 Livestock Loading Exemption Notice 2024 (No.1).