The Longest Bridges in Australia: 2023 Edition

Australia is home to many iconic bridges - from the Sydney Harbour Bridge to the West Gate Bridge in Melbourne, each bridge has its own unique design and story. These engineering feats aren’t just aesthetically valuable: they’re integral to transportation for many Australians. But which bridges are the longest, and which one rules them all?  

1. The Macleay Valley Bridge, NSW

Key facts:

Length: 3.2 km

Location: Fredrickton, NSW

Project: The Kempsey Bypass Project

Designed by: Abigroup (now Lend Lease).

Australia’s single longest road bridge, the Macleay spans the floodplain at Frogmore and the Macleay River at Fredrickton, totalling over 3km in length. It’s part of the Kempsey Bypass Project, the first stage in the approved 40km highway upgrade from Kempsey to Eungai, and was 10 years in the making from 2003-2013, with the bypass alone costing $618 million to the Australian government.

The bridge, a 20-minute drive south of Kempsey, NSW, features three automobile lanes, a shielded footpath, and 941 concrete beams. It was built instead of an on-ground road to avoid the seasonal flooding that plagues the farms below.

The South Road Superway Bridge, SA

Key facts:

Length: 2.8 km

Location: Adelaide, SA

Project: South Road Superway

Designed by: Rizzani de Eccher, and Freyssinet

The South Road Superway Bridge is the second longest bridge in Australia, and is the first elevated roadway to be built in South Australia. It's a 2.8km long elevated roadway that links the suburbs of Regency Park and Cheltenham in Adelaide. 

The Superway features over 4.4 km of non-stop motorway lanes and 11 entry/exit ramps. The Superway was built to reduce congestion and provide a non-stop corridor between the North and Southside, with construction beginning in April 2011 before being completed in early 2014

3. Houghton Bridge & Ted Smout Memorial Bridge, QLD

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Key facts:

Length: 2.7 km

Location: Brisbane, QLD

Project: Houghton Bridge Duplication

Designed by: JF Hull Holdings, and Albem Operations 

The Houghton Bridge and Ted Smout Memorial Bridge is a side-by-side bridgeway that allows vehicles to travel from the Brighton area in South East Queensland, to Redcliffe, by crossing the Hays Inlet.

Houghton Bridge was built 1.61 m higher than Hornibrook – and originally, both these bridges were meant to be used in conjunction, but the Hornibrook Bridge was in such poor condition that the repair would have been too costly. 

The Ted Smout Bridge was made to ease the strain of traffic the Houghton Bridge was experiencing and was officially opened in 2010, situated 35m east of the Houghton Bridge and carrys southbound traffic across to Brighton, while the Houghton Bridge carries northbound traffic into Redcliffe.

4. West Gate Bridge, VIC

Key facts:

Length: 2.5 km

Location: Melbourne, VIC

Project: West Gate Bridge project

Designed by: Freeman Fox & Partners

The West Gate Bridge is a vital link that connects Melbourne’s western suburbs to the CBD. Carrying 200,000 vehicles a day (making it one of Australia’s busiest road corridors), construction began in 1968 and was meant to be completed in 1970, but the construction of the bridge turned out to have quite a tangled history.

On October 15th 1970, a 112-metre span of the bridge collapsed, which caused the deaths of 35 workers, and Freeman Fox and Partners were found guilty of improper structural design. The original contractors, World Services & Construction Pty Ltd, were also found guilty of putting forward inadequate safety margins.

The safety issues and structural problems of the bridge were eventually resolved, and the bridge was completed in 1978, and has safely been in use ever since.

5. Sir Leo Hielscher Bridge, QLD

Key facts:

Length: 1.6 km

Location: Brisbane, QLD

Project: Sir Leo Hielscher Bridge

Designed by: AECOM

The Sir Leo Hielscher Bridge, more commonly known as the Gateway Bridge, is a 1.6km long bridge connecting the Brisbane suburbs of Murarrie and Eagle Farm. Opened in 1968, it cost $92 million to build. Which, frankly, seems almost cheap by today's standards!

In 2005, it was announced that the city were upgrading the Gateway Bridge by constructing a duplicate of it to carry only southbound traffic. This duplicate bridge was named the Sir Leo Hielscher Bridge and was opened in 2010, costing $350 million to build (which, as you can see, is the effects of inflation in action). The Sir Leo Hielscher Bridge (Brisbane residents still call it the Gateway Bridge to this day) carries up to 108,000 vehicles per day.

6. The Sydney Harbour Bridge, NSW

Key facts:

Length: 1.149km

Location: Sydney, NSW

Project: Sydney Harbour Bridge and Metropolitan Railway Construction

Designed by: Dorman

Long After 20 years of planning and eight years of building, the Sydney Harbour Bridge opened to the public in 1932. It used 95,000 cubic metres of concrete, 17,000 cubic metres of granite, 52,800 tonnes of steelwork and around 6 million rivets and 1400 workers in construction.

It sits 130m above the water at its highest point, where tourists and climbers look out at the Opera House and the city centre and colloquially call it ‘The Coathanger,’ after its, well, distinctive shape.

7. Bowen Bridge, TAS

Key facts:

Length: 976 m

Location: Hobart, TAS

Project: Bowen Bridge project

Designed by: Leighton Contractors

Last but not least, the Bowen Bridge is a four-laned road bridge that crosses the Derwent River in Tasmania, linking the eastern and western shores of Hobart. It has a 17.3 metres clearance and has 10 spans.

The Bowen Bridge was built after the collapse of the Tasman Bridge, which occurred in 1975. It cost $49 million to construct and was officially opened in 1984. 

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