Decision Framework for Working Widths in Road Tunnels

⁠⁠⁠Overview

Austroads Ltd is seeking a suitably qualified consultant to develop a tunnel-specific, risk-informed decision framework for working widths in road tunnels, in relation to the Austroads Guide to Road Design Part 6: Roadside Design, Safety and Barriers (AGRD Part 6).

Purpose

The purpose of this project is to develop a tunnel-specific, risk-informed framework to determine how to reduce widths and costs of road tunnel designs so they can safely depart from working-width provisions in AGRD Part 6. This will avoid unnecessary tunnel size and cost while managing safety, operational and maintenance risks.

Scope

The scope includes:

• Delivering an evidence-based, road tunnel-specific decision framework and guidance enabling consistent application of AGRD Part 6 working width provisions
• Determining whether departures from AGRD Part 6 working width provisions are acceptable, and if so, when and how they may be justified
• Converting a contested, project-by-project debate into a repeatable process grounded in a literature and practice review
• Gathering operator-led evidence on impact likelihood and consequences, including vehicle rollover mitigation measures
• Undertaking a structured tunnel risk and interface assessment
• Producing a decision framework, departure pathway, worked examples and documentation templates that delivery authorities can apply early in planning and design to clarify requirements for bidders and manage safety, operational and maintenance risks transparently
• Considering existing and emerging mitigation measures, including barrier systems, sway protection and other treatments that may influence impact likelihood and consequence within tunnels

Deliverables

• Research report
• Webinar
• Project data with populated metadata spreadsheet

Intended end users

The intended end users of the final research report include Austroads transport member agencies, tunnel delivery authorities, tunnel designers and contractors, and tunnel operators and maintainers.

The guidance package is a maintained product only in the sense that it can be periodically updated by Austroads if required as standards and practices evolve.

Instructions to Tenderers

Tender documents and the associated forum can be accessed here: View documents and forum