Delivering technical advisory and construction observation and monitoring for a major four-lane motorway from Kāpiti to Wellington

Transmission Gully—Principal’s Technical Advisor

Transmission Gully is one of New Zealand’s most significant greenfield roading projects. Greenfield construction is where development takes place on land that has never been used for built environments. At 27 kilometres long, the corridor has four lanes, 25 bridge structures, and four grade-separated interchanges. The project was the first roading project in New Zealand to be procured under a public-private partnership delivery model—to finance, construct and operate large, complex pieces of infrastructure. 

As technical advisors we provided pre-contract and post-financial support. For pre-contract tasks we prepared a site investigation program and managed additional geotechnical analysis and baseline environmental monitoring programs. We supported the tendering process, reviewed safety audit reports, assisted with negotiating technical schedules, and scoped the final independent reviewer agreement. During the design and construction phase, we reviewed design documents against works requirements and good practice, observed construction, and monitored construction methodology and quality. We also provided management, surveillance and quality assurance (MSQA) tasks on related projects like the Pāuatahanui Golf Course Redevelopment.

By focusing on the key project outcomes—high safety, reduced travel time, route resilience, and increased customer satisfaction—we helped Waka Kotahi deliver a safer, more reliable, and resilient motorway.