Performance Based Standards



Performance Based Standards (PBS) offers potential for heavy vehicle operators to achieve higher productivity and safety through innovative vehicle design.  PBS focuses on how well a vehicle behaves on the road, through a set of safety and infrastructure protection standards, rather than assessing a vehicle based on prescriptive limits and we are committed to supporting the use of innovative PBS vehicle combinations which result in safer and higher productivity vehicles on WA roads.  

Should you wish to introduce an innovative vehicle which is outside the scope of any of our existing permit products, we encourage you to seek approval via the PBS Scheme. To learn more about the benefits of PBS vehicle combinations, the following fact sheets have been created.


The WA PBS Process

The WA PBS process should be followed if you only intend to use your PBS vehicle in WA. If you intend on operating your PBS vehicle in other jurisdictions, the National PBS Process should be followed. 

If you would like a vehicle approved through the WA PBS Scheme, please refer to the following document which outlines the process you will need to follow.


National PBS Process

The National Heavy Vehicle Regulator (NHVR) administers the National PBS Scheme assessing and approving PBS designs on advice from the PBS Review Panel.  You are still required to negotiate road access separately through State or Territory road authorities. As such, it is strongly recommended you contact us prior to engaging a PBS Assessor to obtain "in-principle" approval.

Once a PBS approval is granted by the NHVR, a permit is still required from us to operate the vehicle within Western Australia.


Applying for WA PBS

Obtaining "In-principle" Approval

The first step in the application process is to obtain an "in-principle" approval from us by completing a Performance Based Standards (PBS) In-principle Approval Application Form. 

Obtaining "in-principle" approval ensures your proposed combination and required level of access is achievable.


Engaging an Approved PBS Assessor

Once the initial proposal has been reviewed and an "in-principle" approval has been issued confirming the proposed vehicle combination and transport task is achievable on the requested routes, you will need to engage an approved PBS assessor to have the vehicle assessed in accordance with the WA PBS Assessment Rules and Standards.


Obtaining Final PBS Vehicle Access Agreement and Vehicle Design Approval

Once the PBS Assessment has been undertaken by an approved PBS Assessor, the assessment will be forwarded to us for a full review to ensure all required standards for the design vehicle and the requested access are met. If the proposed operation is WA specific, the PBS assessment does not need to be submitted to the NHVR Review Panel.  If all standards are met, a final PBS Vehicle Access Agreement and PBS Vehicle Design Approval will be issued.


Obtaining Vehicle Exemptions from Department of Transport

 If the vehicle design requires exemptions from Australian Design Rules (ADRs) you will be required to obtain a CEO Exemption from the Department of Transport by completing the application form below.


Engaging an Approved PBS Certifier and Obtaining a Main Roads WA PBS Permit

 When the vehicle has been built, the applicant will need to engage an approved PBS certifier to certify that the vehicle has been built as per the design specifications. The certification documentation needs to be forwarded to us as the final step in the application process, along with a completed PBS Permit Application Form and any CEO Exemptions obtained from the Department of Transport.

The PBS permit is then issued for the vehicle combination, which will include the approved routes and specific operating conditions.  This application can also be used if applying for an amendment to an existing permit i.e. adding certified vehicles or amending a route.


PBS Audit Framework

Vehicle combinations approved under the PBS scheme are assessed, certified and approved based on a specific vehicle design.  To ensure PBS vehicles continue to perform to a high standard, it is essential the vehicles are maintained to their defined specifications, i.e. components are not altered without approval and the vehicle is maintained in good working order.

PBS audits are undertaken to ensure vehicles approved under the PBS Scheme are being maintained to their defined specifications and as such will continue to meet the safety standard that formed the basis of their initial approval. Refer to the following document for further information in relation to PBS audits.


Minimum WA PBS Axle Spacing Requirements

PBS vehicles that do not meet all of the infrastructure related standards may still be approved under the WA PBS Scheme, provided they comply with the minimum axle spacing requirements outlined in the following table:

​Adjacent Axle Group​Minimum Outer to Outer Axle Spacing​Minimum Inner To Inner Axle Spacing​Maximum Mass Permitted
​Tandem to Tandem Axle Groups​6.8 Metres​3.4 Metres​17.5t on Tandem Groups
​Tandem to Tri Axle Groups​8.0 Metres​3.4 Metres​17.5t on Tandem Groups and 23.5t on Tri Groups
​Tandem to Quad Axle Groups​9.2 Metres​3.4 Metres​17.5t on Tandem Groups and 28.5t on Quad Groups
Tri to Tri Axle​9.2 Metres ​​3.4 Metres ​​23.5t on Tri Groups
​Tri to Quad Axle Groups​​10 Metres ​ ​​3.4 Metres​20t on Tri Groups and 24t on Quad Groups
​Tri to Quad Axle Groups​11 Metres ​​3.4 Metres ​​23.5t on Tri Groups and 28.5t on Quad Groups
​​Quad to Quad Axle Groups​​12 Metres​3.4 Metres ​​ ​27t on Quad Groups
​Quad to Quad Axle Groups​12.5 Metres ​​3.4 Metres ​​28.5t on Quad Groups

 Image: PBS Axle Spacing.PNG


60 metre Road Train Signage

Due to Level 4B PBS vehicles (up to 60 metres in length) being the longest road trains approved to operate on the public road network, additional signage is considered necessary to ensure other road users are aware extra caution is needed when overtaking. Refer to the following documents for signage specifications.


For further information about the PBS Scheme in WA please contact or 138 486.


Modified: 08 Apr 2020