Transmission Gully Motorway

The Transmission Gully Motorway is a 27 km four-lane motorway north of Wellington, designed to improve resilience, safety, and connectivity along State Highway 1 (SH1). Constructed under a Public-Private Partnership (PPP) with Waka Kotahi NZ Transport Agency, the project provides a safer and more reliable alternative to the existing coastal route, enhancing access to and from the capital. The motorway’s complex terrain required significant earthworks, bridge construction, and geotechnical stabilization, making it one of New Zealand’s most challenging infrastructure projects.

Project Involvement

• Geotechnical and Earthworks Oversight – Provided consultancy on slope stabilization, retaining structures, and ground improvement to mitigate seismic and weather-related risks.

• Programme and Risk Management Advisory – Assessed construction timelines, identified potential delays, and proposed mitigation strategies to support project delivery under the PPP framework.

• Structural Engineering and Bridge Compliance – Reviewed bridge designs and construction methodologies, ensuring adherence to engineering standards and resilience requirements.

• Commercial and Contractual Governance – Provided guidance on contract compliance, claims management, and procurement processes to optimise financial outcomes.