Bridges

State Highway 2 Wairoa River Bridge near Tauranga, constructed in 1966, is a 177m long post-tensioned concrete structure with mono pier columns supported on pile foundations. Adding a lightweight downstream cycleway extension in September 2020 has extended its utility by providing a vital link to the 'Omokoroa to Tauranga' cycle trail on either side of the Wairoa River. This paper describes the various project constraints and challenges that shaped the design concept and construction methodology of the cycleway extension. The approach adopted for this project enabled a sustainable and cost-effective alternative to a separate cycleway crossing.

This project showcases sustainability in bridge engineering through lightweight modular construction to add a cycleway to an existing bridge close to its load carrying capacity. The adopted design approach minimised the environmental impact of the extension on the ecologically and culturally important Wairoa River Estuary without the need for a separate standalone crossing. The lightweight modular construction also allowed safe installation and minimised traffic disruptions. The project has extended the use of the bridge to pedestrians and cyclists whilst futureproofing the expansion of the cycleway.