Timber Bridge Deterioration Modeling with Main Roads Western Australia
LOCATION
Australia
NETWORK
Main Roads Western Australia (MRWA) is responsible for the road networks in the State of Western Australia. In addition to planning, building, and operating these roads, assets managed include all bridges and associated infrastructure across the network.
CLIENT SINCE
1998
Overview
MRWA manages a large portfolio of bridges, including a significant number of timber structures unique to its regional network. The agency started to face challenges with asset condition forecasting and investment optimization, relying on manual processes for asset planning. There was a need to modernize bridge asset management through a consistent, data-driven platform that could support long-term decision-making and capital works planning with a specific focus on their timber structures. In response to this need, MRWA initiated a two-phase Bridge Deterioration Model (BDM) project with Deighton.
Phase 1 focused on establishing asset families, defining Transition Probability Matrices (TPMs), and validating deterioration modeling under a “do nothing” scenario. The goals for Phase 2 built off this, and aimed to operationalize this framework within dTIMS, integrating Geographic Information Systems (GIS) capability and Life Cycle Cost analysis (LCCA).
Challenge
The complexity of timber bridge deterioration modeling posed to be the main challenge of Phase 2, requiring unique treatment strategies and life-cycle assumptions within an accelerated 16-week delivery window. Early stages of the project also required extensive cleaning and validation of the data in order to ensure a smooth integration and deployment within dTIMS BA. Deighton and MRWA were ready to address these challenges through structured collaboration involving a strong emphasis on communication and documentation.
Solution
The key objective for Phase 2 was to take the proof-of-concept model from Phase 1 and deliver a complete, configurable, and web-based LCCA for the MRWA timber bridges.
High-level deliverables included:
Refinement verification of Phase 1 outputs (including asset families, TPMs)
LCCA configuration for scenario modeling and optimization
Database setup and full data loading of bridge inventory and condition data
Custom dashboard and mapping integration
Development of treatment catalogues tailored to MRWA’s bridge network
Deployment, training, testing, and final system handover
Results
The project improved visibility into long-term bridge performance and renewal needs, with significant advancements in modeling timber structures that were historically more difficult. Through the integration of LCCA, MRWA gained the ability to perform multi-year scenario testing, enabling more informed investment planning. The collaborative approach used during implementation fostered strong internal engagement and ownership, setting the stage for continued success.
“Deighton’s expertise and collaborative approach were central to the successful development of MRWA’s timber bridge deterioration model. The resulting dTIMS model provides the flexibility needed for robust scenario analysis and clear visualization, supporting more informed and transparent investment planning for timber bridge assets”