TCA nationally administers the use of OBM systems linked to the IAP, allowing road managers to grant access to routes that may have previously been unavailable for these vehicle types, due to identified infrastructure risks.

Access demands and productivity considerations are at the core of this development, benefitting road managers and transport operators alike.

Commonly recognised as weigh scales or mass systems, OBm systems typically utilise load cell or air pressure technologies to measure the axle group mass and gross vehicle mass of heavy vehicle combinations.

When linked to the IAP, OBM systems allow road managers to unlock significant productivity gains for transport operators, without necessitating capital intensive infrastructure upgrades.

TCA is currently developing an OBM Functional and Technical Specification which will:

  • Enable OBM systems to be type-approved by TCA
  • Provide greater assurance in the use of OBM systems.

Information for transport operators

Stakeholders interested in operating OBM systems linked to the IAP are encouraged to contact CTA for further information.

Access arrangements which utilise OBM systems linked to the IAP are listed here

Feasibility Report

The OBM Feasibility project report is available here


The use of OBM systems linked to the IAP has been recognised with several local and international awards – the most recent being the ITS Asia Pacific Industry Award at the 20th ITS World Congress in Tokyo Japan, in October 2013.