Engineering New Zealand has called for a clear definition of the problem Auckland’s proposed second harbour crossing is intended to solve, following the New Zealand Government’s renewed focus on the project. The organisation supports undertaking a Detailed Business Case and securing long-term, cross-government agreement before a specific solution is selected.

The assessment should determine whether the primary need is to increase transport capacity, improve network resilience, strengthen connectivity, or accommodate future public transport options. Engineering New Zealand said answering these questions will guide the evaluation of potential engineering solutions, including their technical, environmental, social and economic implications.

The organisation noted that Auckland’s population, transport requirements and urban form will continue to change, meaning any new crossing should be designed to serve future generations over a 50- to 100-year period. It cited the Auckland Harbour Bridge, whose traffic capacity was exceeded relatively soon after opening, as an example of the risks associated with underestimating long-term demand.

Engineering New Zealand said the eventual solution should be judged not by whether it takes the form of a bridge or tunnel, but by whether the planning process identifies the right problem, rigorously assesses the available options and delivers infrastructure capable of serving Auckland and New Zealand for generations.