In 1959, Auckland opened its Harbour Bridge after 3 years of construction. 10 years later, clip-on sections doubled its capacity from 4 lanes to 8 lanes for city traffic

The Auckland Harbour Bridge is often remembered as a warning about building infrastructure too cheaply. The usual story is simple: Auckland settled for a four-lane bridge in 1959, then had to spend heavily on clip-on lanes just a decade later. But the history in the material provided tells a different story. The smaller bridge helped make the project affordable, and the later expansion delivered four additional lanes at a lower relative cost than building a larger bridge from the beginning, as per a report by Greater Auckland.

The result was an eight-lane crossing that grew alongside Auckland rather than requiring the city to pay for all of that capacity upfront.

What was Auckland originally planning?

The idea that Auckland once had a grand six-lane motorway bridge with rail lines and cycleways is part of the story that has grown around the bridge over the years. There was certainly plenty of public discussion in the 1950s. Automobile clubs wanted more lanes, industry pushed for rail, architects proposed different bridge designs, and a group campaigned for a tunnel instead.

The actual 1951 tender was considerably less ambitious.

It called for five general traffic lanes, two footpaths and a basic low-profile arch. The fifth lane was intended as a tidal lane, meaning the bridge was effectively a four-lane road with an additional lane that could be used according to traffic demand.

It was also not designed as a motorway. The planned speed limit was 40 miles per hour, just over 60 km/h, and the main highway north was expected to use routes around the upper harbour.

Rail was never seriously pursued because the required grade would have meant a bridge roughly twice as long. Trams were also being replaced by trolleybuses in Auckland by the early 1950s.

The proposed footpaths were narrow, about 1.8 metres each, and there was no serious proposal for dedicated cycle lanes.

Why was the bridge made smaller?

The real issue was money.

In 1951, the government selected an £8.1 million New Zealand pound tender for the five-lane bridge and its associated works. The bridge itself accounted for £3.5 million, while approach roads cost £2.1 million and reclamation, property and other expenses made up another £2.5 million.

There was another major complication: the project was expected to be funded through international borrowing. The plan involved borrowing in London at 4% interest.

For Auckland at the time, this was an enormous undertaking. The city was much smaller, while the North Shore was still largely rural, with villages around ferry wharves and holiday baches along the coast.

The proposed £8.1 million project represented about 7.5% of Auckland's annual regional GDP.

In 1954, Prime Minister Holland returned with a different approach. The project would be funded locally, but its scope had to be reduced.

The fifth lane and footpaths were removed, cutting £771,000 from the bridge structure. The approach roads were also initially reduced, although narrower versions were eventually restored after political concerns about local traffic.

The revised project was signed for £7.5 million in 1954.

That decision is usually described as penny-pinching. But measured against Auckland's economy, the smaller project represented a significant reduction in the financial burden and helped get the bridge built.

Construction followed, and the Auckland Harbour Bridge opened in 1959.

Did the clip-ons really make the bridge more expensive?

The clip-ons are central to the argument that Auckland made a mistake. In 1969, a Japanese company added separate structures alongside the original bridge. When they opened, the additional lanes doubled the bridge's traffic capacity from four lanes to eight.

The work cost $7.4 million. At first glance, the numbers appear to support the traditional criticism. Auckland had saved £771,000 by making the original bridge smaller, only to spend millions widening it ten years later.

But the comparison is not quite as straightforward. The original cost reduction removed one lane from a proposed five-lane design. That meant a 20% reduction in lane capacity. The clip-ons, however, added four lanes to a four-lane bridge. That represented a 100% increase in capacity.

More importantly, Auckland's economy had grown substantially during those ten years. The $7.4 million cost of the clip-ons represented only about 0.8% of Auckland's GDP at the time.

The smaller original bridge had reduced the financial burden during the 1950s, while the later expansion arrived when Auckland was better able to afford it. The result was an eight-lane bridge without requiring the city to finance all eight lanes from the beginning.

What did Auckland gain from building in stages?

The biggest achievement was perhaps the simplest one: Auckland actually got its harbour bridge. The original project had faced such serious financial difficulties that there was a real possibility the plans would have remained just plans.

Instead, the reduced scheme went ahead. The bridge was completed in 1959, and its construction helped support the growth of the North Shore.

A decade later, the city had enough economic strength and traffic demand to justify a much larger expansion. By the time the loans were paid off in 1984, Auckland had an eight-lane bridge. The staged approach also continued beyond the clip-ons. The bridge was strengthened in the 1980s, received a movable barrier system and electricity and water pipes during the 1990s, and was followed by the northern busway in the 2000s.

The most regrettable part of the original decision, according to the material provided, was that footpaths and a cycleway were not brought back when the clip-ons were added.

Still, the wider history offers a different way of looking at the Auckland Harbour Bridge.

Rather than simply being a story about a cheap bridge that later needed an expensive fix, it became an example of infrastructure expanding as Auckland itself expanded.

FAQs

When did the Auckland Harbour Bridge open?
It opened in 1959.

When were the clip-ons added?
They opened in 1969.