Beca's design and construction teams worked closely together in a dedicated project office, which contributed to the development of economical, easily constructed solutions.
Central Motorway Junction is the convergence of the Southern (SH1), Northern (SH1) and Western (SH16) motorways in central Auckland. Although constructed in the 1970s, the connecting links were not completed until 2007.
A New Zealand Transport Agency (formerly Transit) project, Beca was the lead designer working for the Complete Joint Venture (The Fletcher Construction Company Ltd and Leighton Contractors). Services included geometric design, geotechnical engineering, pavement structures, stormwater drainage, utilities relocation, structural design, signage and traffic management system design.
The project covered a stretch of 22km of existing and new carriageways, ranging from single lane links to five-lane mainline motorway, and included a number of separate construction elements:
- Five new bridges and four existing bridges retrofitted/widened. The new bridges ranged from 35m to 200m long comprising continuous spans of concrete super tee girders supported on single columns and bored piles
- Approximately fifteen retaining walls
- Modifications to existing on/off ramps
- Creation of new road links from the North to the West and Port and vice visa
Design and construction teams worked closely together in a dedicated project office, which was instrumental in addressing the greatest project challenge; co-ordinating all the civil disciplines and construction on heavily trafficked roads with minimal interruption to traffic. This collaborative working environment also contributed to the development of economic, easily constructed solutions for the various new structures. The number of elements - lanes, ramps and geographical topography also required complex geometric design to ensure safety and smooth passage of vehicles through the junction.
Urban design was an integral part of the design process which resulted in an aesthetically pleasing environment for motorists in the Central Motorway Junction area.