Auckland Harbour Bridge

The Auckland Harbour Bridge is an eight-lane motorway bridge over Waitematā Harbour in Auckland, New Zealand. It joins St Marys Bay on the Auckland city side with Northcote on the North Shore side. It is part of State Highway 1 and the Auckland Northern Motorway. The bridge is operated by the NZ Transport Agency Waka Kotahi (NZTA). It is the second-longest road bridge in New Zealand, and the longest in the North Island.

The original inner four lanes, opened in 1959, are of box truss construction. Two lanes were added to each side in 1968–1969 and are of orthotropic box structure construction extend as cantilevers from the original piers. The bridge is 1,020 m (3,348 ft) long, with a main span of 243.8 metres (800 feet) rising 43.27 metres (142 feet) above high water, allowing ships access to the deepwater wharf at the Chelsea Sugar Refinery, one of the few such wharves west of the bridge.

While often considered an Auckland icon, many see the construction of the bridge without walking, cycling, or rail facilities as an oversight. In 2016, an add-on structure providing a walk-and-cycleway called SkyPath received Council funding approval and planning consent, but was not built. In 2021, a stand-alone walking and cycling bridge called the Northern Pathway was announced by the New Zealand Government, but also was not built.

About 170,000 vehicles cross the bridge each day (as of 2019), including over 1,000 buses, which carry 38% of all people crossing during the morning peak.

Prior to the opening of the bridge in 1959, the quickest way from Auckland to the North Shore was by passenger or vehicular ferry. The fastest way via car was through the Coatesville-Riverhead Highway

As early as 1860, engineer Fred Bell, commissioned by North Shore farmers who wanted to herd animals to market in Auckland, had proposed a harbour crossing in the general vicinity of the bridge. It would have used floating pontoons, but the plan failed due to the £16,000 cost estimate ($1.9 million, adjusted for inflation as of March 2017). Additional structures for a bridge crossing the harbour were proposed in 1927 and 1929. Two Royal Commissions in 1930 and 1946 were held on the viability of a bridge crossing the Waitemata.

In the 1950s, when the bridge was being built, North Shore was a mostly rural area of barely 50,000 people, with few jobs and a growth rate half that of Auckland south of the Waitematā Harbour. Opening up the area via a new route unlocked the potential for further expansion of Auckland.

The recommendations of the design team and the report of the 1946 Royal Commission were for five or six traffic lanes, with one or two of them to be reversed in direction depending on the flow of traffic, and with a footpath for pedestrians on each side. The latter features were dropped for cost reasons before construction started, the First National Government of New Zealand opting for an 'austerity' design of four lanes without footpaths, and including an approach road network only after local outcry over traffic effects. The decision to reduce the bridge in this way has been called "a ringing testament to [...] the peril of short-term thinking and penny-pinching". On 1 December 1950, an act of parliament formed the Auckland Harbour Bridge Authority, chaired by Sir John Allum, then Mayor of Auckland City, who appointed British firm Freeman Fox & Partners to design the bridge.