Revised Directional Stability Under Braking (DSUB) standard Performance Based Standards (PBS) Scheme - Effective date: 1 July 2026.

What is changing?

The NHVR is updating the PBS Directional Stability Under Braking (DSUB) standard to modernise braking requirements and improve safety outcomes across the Performance Based Standards (PBS) fleet. The revised standard focuses on the use of advanced braking and stability technologies and introduces assurance measures to confirm these systems are powered, operational and fault-free when vehicles are in use.

Who is affected?

First-time PBS vehicles must comply from 1 July 2026:

• Vehicles entering the PBS scheme for the first time from 1 July 2026 must comply with the revised DSUB standard.

Pre-existing PBS vehicles are not affected:

• Vehicles issued with a PBS Vehicle Approval (VA) before 1 July 2026 are not affected by the revised standard. These vehicles are grandfathered indefinitely (referred to as ‘DSUB-grandfathered’ vehicles) and are not required to be upgraded to comply with the revised DSUB requirements.
• The exception to this is in limited mixed-DSUB-compliance scenarios, as referenced below in section Mixed combinations – minimum electrical requirements.

How to check the PBS status of your vehicle

Operators can check whether a vehicle is a first-time or pre-existing PBS vehicle by contacting the NHVR on 13 NHVR (13 64 87) or by emailing pbs@nhvr.gov.au - the email subject line must include ‘PBS approval status enquiry’. Operators may also contact their preferred PBS Certifier for assistance with PBS approval status verification.

If the vehicle does not appear as PBS-approved before 1 July 2026, it will be treated as a first-time PBS vehicle.

Summary of revised braking requirements

EBS status indicators

PBS combinations must have a device or devices fitted to show that the braking systems on all trailing units are:

• connected, powered on, and
• provide system fault status.

This requirement can be met through the use of:

• Trailer EBS diagnostic displays fitted to all trailing units, including dollies (including but not limited to Wabco SmartBoard, Knorr-Bremse Trailer Information Module or Haldex Info Centre); or
• an in-cab display connected to the Trailer EBS system, including factory-fitted OEM displays (some European truck models communicate with Trailer EBS to display trailer axle load information); or
• in-cab displays forming part of an On-Board Monitoring (OBM) system (including, but not limited to, the Knorr-Bremse iMass Driver Interface Unit).
• Other in-cab OBM or OEM displays may be acceptable, provided they connect directly to the Trailer EBS system and provide trailer-specific power and fault status.

Use of status lights

The revised DSUB standard does not explicitly prohibit the use of trailer-mounted status lights. However, at this time there is no clear legal pathway to support their use in practice. As a result, trailer-mounted lights will only become a viable option once this matter is resolved, either through updates to the relevant Australian Design Rules or via a Vehicle Standards Exemption notice.

The NHVR will continue to work closely with the Commonwealth to find a pathway for the fitment of status lights and is aiming for this issue to be resolved by the DSUB go-live date.

Mixed combinations – minimum electrical requirements

If a DSUB-grandfathered vehicle operates in a combination which includes a new DSUB-compliant vehicle - new trailer or dolly entering the PBS scheme for the first time from 1 July 2026 that must comply with the revised DSUB standard - basic electrical compatibility is required. These requirements ensure new DSUB-compliant vehicles can function correctly.

The below requirements are for DSUB-grandfathered vehicles if used in combinations with new DSUB-compliant vehicles.

DSUB-grandfathered vehicles

Hauling units:

• Must have a rear ISO 7638 connector:
  • Road train: ISO 7638-1 (24V).
  • Non-road train: ISO 7638-1 (24V) or ISO 7638-2 (12V).

Trailers and dollies:

• Must pass electrical power from front to rear ISO 7638 connectors.
• Wiring must support downstream EBS and stability systems.
• Does not require to have its own brake status indicator device fitted.

Further information for PBS operators

In-service vehicles entering PBS for the first time after 1 July 2026

Existing in-service vehicles entering PBS for the first time after 1 July 2026 must meet the revised DSUB standard when applying for PBS approval. If a braking upgrade is required:

• Retro-fitment must comply with VSB 6.
• A copy of VSB 6 modification plate will be required as part of PBS certification evidence.

PBS Vehicle and Design Approvals

From 1 July 2026, all existing PBS Design Approvals (DA) are deemed to comply with the revised DSUB standard and do not require updates. Similarity, all existing PBS Vehicle Approvals (VA) will remain valid and do not require updates.

Recording DSUB compliance on PBS VAs

For first-time or additional VINs added to a VA from 1 July 2026, DSUB compliance status will be recorded on VAs through a DSUB label, which will encode the type of braking system fitted and DSUB compliance status.

Access permits

Existing and future PBS access permits are not affected by the revised DSUB standard.

NHVR support

If you have questions or require further information on the revised Braking standard for PBS vehicles, please contact the NHVR’s PBS Enhancements Team at PBSReview@NHVR.gov.au.

Note: This information sheet is a summary only. Please refer to the PBS Standards and Vehicle Assessment Rules for full legal requirements.