Sturt Highway is an Australian national highway in New South Wales, Victoria, and South Australia. It is an important road link for the transport of passengers and freight between Sydney and Adelaide and the regions along the route.
Initially an amalgam of trunk routes, the Sturt Highway was proclaimed a state highway in NSW in 1933. In 1955, the route was allocated a National Route number (20). It was included in the National Highway system in 1992, forming the Sydney-Adelaide Link. Sturt Highway is allocated as route A20 for its entire length, the majority of which is a single carriageway, and freeway standard and 6-lane arterial road standard towards its western terminus in Gawler.
Route
The highway is the shortest, highest-standard route between Sydney and Adelaide. It runs generally east–west, roughly aligned to the southern bank of the Murrumbidgee River in New South Wales. Following that river's confluence with the Murray River, it is then roughly aligned to the Murray through north-western Victoria and eastern South Australia, before it heads towards the northern outskirts of Adelaide. through the Parliament of New South Wales provided for the declaration of Main Roads, roads partially funded by the State government through the Main Roads Board (later Transport for NSW). Main Road No. 4 was declared along this road from the intersection with Hume Highway from Lower Tarcutta to Wagga Wagga (and continuing eastwards via Tumut, Adaminaby, Cooma, and Bega to Tathra) as part of Monaro Highway, to provide for additional declarations of State Highways and Trunk Roads, these were amended to State Highways 4 and 6 and Trunk Road 58 on 8 April 1929.
Mid-Western Highway was rerouted between Gunbar and Balranald to pass through Hay, and the western end of Trunk Road 58 was truncated to meet it at Hay, on 24 September 1929. The route of the main road from Narrandera to Darlington Point had shifted to the southern side of the river at this stage, thus following the present route east from Balranald. On 16 September 1930, the road between Wagga Wagga and Hay (Trunk Road 58) was named Sturt Trunk Road, in honour of Captain Charles Sturt who explored the area a century earlier and opened it up for agriculture.
The Department of Main Roads, which had succeeded the MRB in the previous year, declared Sturt Highway as State Highway 14 on 8 August 1933, from the intersection with Hume Highway at Lower Tarcutta via Wagga Wagga, Hay, Balranald, Euston and Wentworth to the state border with South Australia, subsuming the existing portions of Monaro Highway (State Highway 4) between Wagga Wagga and Lower Tarcutta, Sturt Trunk Road (Trunk Road 58) from Wagga Wagga to Hay, and Mid-Western Highway (State Highway 6) from Hay to the state border with South Australia. eventually to Adelaide via Renmark; and was declared a State Highway by the Country Roads Board of Victoria in September 1932.
Sturt Highway was signed National Route 20 across its entire length in 1955. The Whitlam government introduced the federal National Roads Act 1974, where roads declared as a National Highway were still the responsibility of the states for road construction and maintenance, but were fully compensated by the Federal government for money spent on approved projects.
The passing of the Roads Act of 1993 through the Parliament of New South Wales updated road classifications and the way they could be declared within New South Wales. Under this act, Sturt Highway today retains its declaration as Highway 14, from the intersection with Hume Highway north of Tarcutta to the bridge over the Murray River at Mildura.
The passing of the Road Management Act 2004 through the Parliament of Victoria granted the responsibility of overall management and development of Victoria's major arterial roads to VicRoads: in 2004, VicRoads re-declared Sturt Highway (Arterial #6610) from the border with South Australia at Murray-Sunset to the border with New South Wales in Mildura.
Upgrades
South Australia
None of the Sturt Highway was originally constructed as dual-carriageway. Work began in January 2007 to upgrade the highway to a four-lane, dual-carriageway road between Gawler Bypass and Greenock in the Barossa Valley. The project was completed in 2010 with budget savings directed towards further Sturt Highway improvements.
Northern Expressway was built at the south-western end of Sturt Highway, as part of an AusLink/Government of South Australia project to build a new freeway-standard road, as part of the North–South Corridor project, providing better access for road transport to Port Adelaide and the industrial areas west and northwest of Adelaide.
Other projects in South Australia include a number of overtaking lanes added in the 2000s and 2010s to help make it safer with the high volume of traffic. Major 'S'-bend curves near Waikerie were realigned, and further upgrades to the road were performed up to 2012.
Significant route changes
The original route of Sturt Highway in the Riverland passing through Berri and Glossop was bypassed to pass through Monash in 1995. The former alignment is now known as the Old Sturt Highway, route B201. The original route passed through the middle of the Barossa Valley, along what is now the Barossa Valley Way. This first changed to a route passing to the north of Nuriootpa, around to the north and west of Gawler on the Gawler Bypass and Main North Road to Gepps Cross. It later changed to use the Northern Expressway instead. A realignment in the 1990s led to it bypassing Daveyston and Shea-Oak Log instead of passing through these small towns.
When the Northern Expressway and Northern Connector were assigned as route M2, route A20 reverted to following Main North Road south to Gepps Cross.
Truro bypass
A new alignment is proposed to be built to the north of the town of Truro, to remove the highway traffic from the main street of the town. The bypass is proposed to be funded by the Australian government for $161.6 million and state government $40.4 million. Construction is expected to start late in 2022 and be completed by the end of 2026. The project will adjust the alignment to reduce the steep hill between the Murray Flats and Truro. It will be built to a standard suitable for triple road trains.
Victoria
There is a proposed Mildura Truck Bypass, to be funded by Auslink 2.
Major river crossings
From east to west, the Sturt Highway follows much of the course of the Murrumbidgee River, on its southern banks, from the Sturt's eastern terminus with the Hume Motorway. At , the Sturt Highway crosses the Murrumbidgee, carrying the highway to the north of the river via the Balranald Bridge.
To the west and south-west, Sturt Highway crosses the Murray four times:
- Between Buronga and Mildura, carrying the highway to the south of the Murray over the George Chaffey Bridge, a high concrete-girder bridge that was opened in 1985.
- Between and Renmark, carrying the highway to the north of the Murray over the Paringa Bridge, a lift-span bridge which used to have a railway through the middle as well as vehicle carriageways on each side.
- Between and Kingston On Murray, carrying the highway to the south of the Murray over the Kingston Bridge, a high bridge from an embankment on the right bank to the cliffs on the left bank. It replaced cable ferries, and was itself replaced in 1998 in response to concern about its ability to continue to carry B-double trucks. The bridge at Kingston On Murray was opened in 1973, also replacing a very busy ferry crossing.