How many state highway bridges in use today, if any, does the New Zealand Transport Agency expect to have a total lifespan of 150 years or more?

Answer

I am advised that NZTA does not generally assess or maintain forecasts of the ultimate lifespan of individual state highway bridges for investment decision-making purposes. Bridges are designed for a specified design working life, typically 100 years under the NZTA Bridge Manual, but their actual service life depends on factors such as material durability, loading, environmental exposure, maintenance, renewals and changing network requirements. While NZTA undertakes long-term asset life and renewal forecasting to support network-level planning and investment, it does not hold a count of state highway bridges that are expected to achieve a total lifespan of 150 years or more.