Transport for NSW & Aurecon – Coffs Harbour Bypass Risk Assessment for Dangerous Goods Vehicles through Tunnels

Project Summary

The Coffs Harbour Bypass (CHB), a 14km bypass with three tunnels, aims to improve road safety, deliver road freight efficiency for heavy vehicles and easing congestion.

Due to years of uncertainty for decision making on the transport of dangerous goods (DG) through the tunnels, Regional Outer Metropolitan division, Safety Environment and Regulation division, Infrastructure and Place and technically supported by Aurecon, found an innovative best practice approach to conduct an independent quantified risk assessment. Our work used best practice principles defined in the TfNSW Asset Management Framework to balance cost, risk, and performance to demonstrate the desired customer-focused safety and value outcomes.

Project Description

A serious incident involving dangerous goods in a tunnel can be extremely costly in terms of loss of human lives, environmental degradation, tunnel damage and transport disruption. Conversely, needlessly banning dangerous goods from tunnels may create unjustified economic costs. Moreover, such a ban might force operators to use more dangerous routes, such as densely populated areas, and thus increase the overall risk to the public.

A number of previous studies over previous years had been attempted as a part of the design and evaluation process to transport the dangerous goods (DG) through the Coffs Harbour bypass. However, those studies were not sufficient to drive a robust decision-making process within Transport for New South Wales (TfNSW).

Following the intensive review of the previous studies and evaluation of the project scenario, the Tunnels team in Asset Management Branch (AMB), under the direction of Director Civil Engineering Infrastructure, made the decision to consider the best practice Asset Management principles of an outcomes-based approach and safe systems in line with TfNSW Asset Management Framework to guide this work. Such a decision should get assurance through a systems and safety engineering approach for the tunnel design and operational procedures by considering the risk and consequent design based on the so far as is reasonably practicable (SFAIRP) framework.

What we did

A project brief was prepared and sent to market with clear work sprints to be completed within a tight timeframe of six weeks. Aurecon responded with an innovative approach, adapting quantitative risk assessment methodologies and frameworks from the major hazard industry, purchasing an international modelling tool and ensuring a methodology of asset management that enables decision making with engaged stakeholders.

The focus of completing the quantified risk assessment is outlined below

  • Provide and independent verified study of work
  • Quantification of risk (i.e. likelihood and consequence)
  • Provide an absolute level of risk that can be used to inform internal and external stakeholders of the risks associated with DGVs using the CHB
  • Provide comfort to communities and industry
  • Potential to demonstrate innovation in design
  • Confirm effectiveness of some mitigation measures as part of an SFAIRP demonstration

The absolute risk assessment demonstrated the DG vehicles currently travelling through Coffs Harbour can be rerouted along the CHB. Further scenario development of increased and different types and quantities of DG vehicles can help inform decision making to future proof the design and operation of the bypass. The assessment concluded that the detailed design development can proceed with the appropriate safe design studies and fire and life safety studies to determine the fire and smoke protection requirements for the tunnels as part of the demonstration risks are eliminated or reduced SFAIRP.

How we did it

The DG risk assessment project was completed successfully under very tight timeframe of six weeks to meet the project schedule to tender out for the detailed design. The management of the project was underpinned by defined work sprint packages and an innovative solution that achieved the desired outcome. This couldn’t have been possible without the rigorous focus on human centric safety principle through a systems and safety engineering asset management approach.

In additional to the technical analysis required for this project, a key objective of this project was also to collaborate with all relevant internal stakeholders and bring them along the journey in seeking their inputs into the modelling, providing an opportunity for them to voice their concerns and feedback as well as gaining endorsement from the various CHB teams and executives. It was incredibly important to gain buy-in from the relevant stakeholders for this project to be successfully accepted by TfNSW and set the precedence for future Quantitative risk assessments to be undertaken. To achieve this high level of best practice engagement, Aurecon and TfNSW following stakeholder mapping, engaged with over twenty one key stakeholders from executives to the project delivery team, through one-on-one interviews and collaborative on-line workshops using Aurecon’s design to innovate approaches.

The team lead by Director of Civil Engineering Infrastructure prepared a comprehensive project brief and managed the project to meet the short timeframe to meet the clients requirements and assist the senior management team with the clear recommendation for decision making with facts and figures based on the modelling with the available tools, scientific analysis and risk demonstration of eliminating or reducing risk SFAIRP.

Why we did it

This study concluded that transit of DG vehicles through Coffs Harbour bypass is practical, which has a significant saving in the travel time costs, address the demands for the transformation of the transport, reduces the safety risk of transporting dangerous goods through congested city centres with vulnerable communities and ultimately contributing enormous environmental and societal benefit.

This study showed that transport of DGs through the CHB tunnels may slightly increase CAPEX and OPEX in compared to the current practice in tunnels, however, it provides significant economic benefit by saving travel time costs; enhancing the safety measures to mitigate the risks to the surrounding community and its customers; addressing the demands for the transformation of the transport; and ultimately contributing enormous environmental and societal benefit both directly and indirectly for this and all future infrastructure projects across Australia.   

Specific Contributions

“We are proud of what we’ve brought to the conversation in terms of a fresh set of eyes, Aurecon’s design to innovate methodologies and our human centric safety approach to asset assurance.”

—Delene Kock, Principal, Asset Management

Through this successful demonstration project Transport for New South Wales can lead Australia through its contribution to

  • Establish a risk assessment methodology for dangerous goods through tunnels with Coffs Harbour Bypass as a case study
  • Influence the legal framework that allowed dangerous goods in existing tunnels through a demonstrated asset management approach
  • Outline performance requirements and mitigation measures for safe operations and asset assurance
  • Incorporate the key learnings in a standard, currently under development for dangerous goods through tunnels

“Our team used best practice asset management principles in our collaborative approach to evaluating the risk assessment for the Coffs Harbour Bypass project. The team was focused on balancing cost, risk, and performance to demonstrate our desire for customer-focused safety outcomes.”

  • Diana Zagora, Director Civil Engineering Infrastructure

Our approach to the project is industry leading, entailing deep collaboration to improve and embed Asset Management principles and behaviours for a robust methodology to remove uncertainty around decision making to transport dangerous goods through the tunnels.

General Comments

While the project has delivered extensive value so far, we are proud to be committed to this work on a long-term basis. As the journey continues, additional innovations will be embraced to articulate value for dangerous goods through tunnels as we work towards achieving our Asset Management goals

  • to plan for a transport system that meets the needs and expectations of the public and customers
  • to promote economic development and investment
  • to provide integration at the decision-making level across all transport modes
  • to promote greater efficiency in the delivery of transport infrastructure projects 
  • to provide safe and reliable delivery of transport and productive freight services

Transport for NSW is committed to delivering transport which contributes to economic prosperity and social inclusion in an environmentally responsible and sustainable manner, and a vision to create a NSW where every journey is people and planet positive.


DG Risk Framework: Hazards related assessment process – (Aligning with HIPAP)

Modal Overall Output

Dangerous Goods Classification

CHB Traffic Route

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