Bridge Families

Under the Bridge Families Pilot, 'like' structures are grouped by age, construction material and type to determine if the asset capability of a known structure can be applied with the aim ofsupporting road manager access decisions.

Why is the Bridge Families Pilot important?

The local government network is estimated to include comprising 24,000 bridges, with individual assessments restricted by:

  • time to complete the volume of assessments
  • data availability and design drawings
  • assessment costs. 

To balance the need to understand the national asset pool and asset capacity, SLGAAP is adopting an upscaling process to use the learnings from a smaller population of bridges (that have design drawings) and apply these learnings to generic bridge families (like bridges). It is expected that the Bridge Families Pilot will improve efficiency and assessment outcomes across a greater proportion of the asset base while preserving quality in bridge capability determination. 

There are four main areas the Bridge Family Pilot will focus on: 

  • Latent capability of the asset
  • Reduced inherent capability of the asset
  • Plausibility gaps 
  • Development of appropriate reference vehicles. 

See the FAQs for definitions.


Identification and Classification 

Bridge family analysis is focused on categorising bridges with similar traits in order to apply of known behaviours to similar bridges that have not been assessed in a comprehensive manner.

At the primary level bridges can be classified according to their material type. Material types considered will include: 

  • Concrete 
  • Steel 
  • Timber. 

Another important classification marker is the design era the structure was created from. Historically, design loads have changed over time and are a critical categorisation requirement.