Project Overview

TAG Advisory was engaged by the Public Transport Authority of Western Australia (PTA) to provide comprehensive cost estimation services for the Bunbury Faster Rail project; a transformative regional rail initiative aimed at improving connectivity between Perth and Western Australia's South West region. The engagement encompassed high-level cost advice for over 40 route alignment options and detailed feasibility-stage estimating for the preferred alignment, supporting critical business case development for this significant infrastructure investment.

Key Challenges

The project presented unique complexities in developing accurate cost estimates across multiple alignment options whilst maintaining consistency and comparability. Each route option presented distinct engineering challenges including varied geological conditions, environmental constraints, land acquisition requirements and integration with existing rail and road infrastructure.

The requirement to align estimates with both PTA Project Cost Estimating Guidelines and Federal Government standards added additional complexity. Meeting Department of Infrastructure, Transport, Regional Development, Communications and the Arts requirements through Guidance Notes 1-4 demanded rigorous methodology and comprehensive documentation to support funding applications.

Methodology and Approach

TAG Advisory implemented a systematic approach to deliver robust cost estimates across all project phases. Initial high-level cost advice for over 40 route alignment options enabled informed Multi-Criteria Assessment (MCA), providing comparable cost inputs for strategic decision-making. Each option was assessed considering earthworks requirements, structure needs, systems integration, property impacts and constructability factors.

Following route selection, the team developed a detailed Class 5 Feasibility Design Cost Estimate for the preferred alignment. This comprehensive estimate incorporated:

• Civil infrastructure including formation, drainage, and structures
• Environmental mitigation and management measures
• Land acquisition and property adjustment costs
• Operational system requirements and integration
• Professional services and project delivery costs
• Risk allowances and contingencies aligned with project stage

All estimates strictly adhered to both PTA guidelines and Federal funding requirements, ensuring consistency with national infrastructure investment frameworks.

Outcomes and Value

TAG Advisory's cost estimation services provided the PTA with robust financial foundations for the Bunbury Faster Rail business case. The comprehensive assessment of alignment options enabled evidence-based route selection, optimising value for money whilst meeting technical and community requirements.
The detailed Class 5 estimate for the preferred alignment established a credible budget basis for Treasury and Federal funding submissions. Clear documentation of methodology, assumptions and risk assessments enhanced stakeholder confidence and supported successful progression through gateway reviews.

Conclusion

The Bunbury Faster Rail project showcased TAG Advisory's expertise in delivering complex cost estimation services for major transport infrastructure. By providing rigorous, standards-compliant estimates across multiple options and detailed feasibility-stage costing, TAG Advisory enabled informed decision-making and successful business case development for this critical regional connectivity project.