The subject of a third harbour bridge has come up several times in the past few decades.

We climb to 500 feet, soaring over the harbour bridge.

I walked for miles around this part of the city, along the quayside, into the botanical gardens and up onto the harbour bridge itself.

An iconic structure of Auckland, the harbour bridge is also a bottleneck for traffic.

"I thought you said the Harbour Bridge was impossible," she said dryly.

It runs southbound on the outer carriageway and across the Harbour Bridge.

After the construction of the Harbour Bridge in 1959, cheap housing subdivisions completed the transformation into an urban area.

Initially, the motorway was limited access, with all ramps facing towards the Harbour Bridge.

Until 1967 the Harbour Bridge was Sydney's tallest structure.

Even with the clip-on sections and the traffic management in place, the Harbour Bridge was soon experiencing severe congestion during rush hours again.