|This article needs additional citations for verification. (January 2014)|
|Main South Road at the northern end of the expressway (looking south), closed to south-bound traffic|
|Length||21 km (13 mi)|
|Opened||17 December 1997|
|Maintained by||Department of Planning, Transport and Infrastructure|
|Major suburbs / towns||,|
The Southern Expressway is the world's longest reversible one way freeway, although the expressway is currently being turned into a regular 2-direction freeway. Originally proposed as 'Noarlunga Freeway', it was built as a corridor to relieve heavy traffic from the major arterial, Main South Road, in Adelaide's south. The expressway was built in two stages — the first completed in late 1997, the second in 2001. The total cost of the arterial was A$76.5m, and it is 21 km in total length. Main South Road provides both the start and finish. There are exits at Marion Road, Panalatinga Road, Sherriffs Road and Beach Road. The Southern Expressway is signed as M2.
Construction of the expressway also included the Adelaide Southern Veloway for cyclists, which runs alongside it for 7 km, from Marion/Main South Road to the Panalatinga Tunnel. South of the Panalatinga Tunnel, the bikeway becomes a shared track for the remaining 12 km of the expressway. The expressway crosses over the Coast to Vines rail trail at both Panalatinga Road and at the expressway's Southern end.
On 17 February 2010 Premier Mike Rann announced that the expressway would be duplicated in a A$445m project, including a new A$75m interchange at Darlington (which was later scrapped ). This was driven by the planning of a major transport hub at Darlington, during which the government discovered that it faced having to build a $50 million section of road that would have to be destroyed when the expressway was eventually duplicated.
The new road will be built entirely on the western side of the current roadway, and will be 4 lanes between Reynella and Marion Road in the Northbound. Once complete, the expressway open 24 hours a day, in both directions, removing much confusion from locals and visitors as to when, and which direction the Expressway is open. Accessibility will be improved with the project, with completely new intersections at Beach Road and Sheriffs Road, as well as being able to left turn out at Old Noarlunga, right turn out at Marion Road, and left turn in at Marion Road.
Works are currently underway, and the 2-way expressway is expected to open to traffic in 2014.
The expressway is open approximately 22.5 hours per day, one way for over 11 hours in each direction. The northbound (city-bound) direction occurs on weekday mornings (2:00am – 12:30pm) and weekend evenings (2:00pm – 12:30am), the southbound direction on weekday evenings (2:00pm – 12:30am) and weekend mornings (2:00am – 12:30pm). It is closed 12:30am – 2:00am and 12:30pm – 2:00pm, except for Saturday and Monday mornings when the direction remains unchanged. Weekday public holidays also operate under the weekend's opening times to accommodate tourists travelling to the Fleureiu Peninsula. During each closure all road signs, lights and boom gates change over, and the road is inspected by a tow truck contractor for debris and car breakdowns.
The expressway is the southern part of a north-south freeway originally conceptualised under the Metropolitan Adelaide Transport Study (MATS), completed in 1965, as a freeway bypassing the city from Dry Creek to Old Noarlunga. The MATS plan proved unpopular, and in 1971 all further highway construction in Adelaide was postponed for a period of ten years. In 1983 plans for the freeway north of Darlington were abandoned, and the land that had been set aside was progressively sold off.
In 1984 the state government announced plans to develop a "third arterial road" for the south. In 1987 the project was split into two phases, the first the upgrading of Main South Road and Marion Road in the Darlington area, and the second a new road from Darlington to Reynella. Phase one was completed in 1994 with the widening of Main South Road to eight lanes between Ayliffes Road and Seacombe Road, and the widening of Marion Road to six lanes between Main South Road and Sturt Road.
Phase 2 became the expressway, which was to be constructed in two stages: from Darlington to Reynella, and from Reynella to Old Noarlunga. It was developed as a one-way reversible road with future duplication provided for in the roadworks base, to be constructed when the need arose. It used the remaining "Noarlunga Freeway" reservation, except for the northernmost kilometre where a new route through O'Halloran Hill was chosen to provide high-quality links with Marion and Main South Roads without interfering with existing infrastructure at Sturt.
Construction of the expressway commenced in July 1995 and the first stage was opened to traffic on 17 December 1997. Construction commenced on the second stage in February 1999 and was opened to traffic on 9 September 2001.
Although a boon to residents living a substantial distance south of the CBD, the expressway does not commence until some 15 km south of the CBD. This fact, combined with its one-way operation, design compromises, and the fact that it bypasses large sections of existing freeway-class road, have led many to question its benefit.
On 17 February 2010, during the state election campaign, Premier Mike Rann announced that, if re-elected, the government would commit $445 million for the ‘duplication’ of the expressway, enabling traffic to flow both ways simultaneously. Premier Rann said that construction would begin at the end of 2011 and should be completed by mid-2014.
Once duplication was announced in 2010, construction started one year later in 2011. The first construction-related expressway closures were 3 consecutive days in January 2012, out of peak hours, but is the most disruption the road has experienced since the opening of Stage 2, with only day-long resurfacing of line-marking, and cycle rides disrupting the expressway previously.
Exits and intersections
|Southbound exits||Distance from
|Start Southern Expressway
continues from Main South Road
|0 km||End Southern Expressway
Merges with Main South Road
to & City
|no exit||City via Main South Rd
|no exit||0.5 km||City via Marion Rd
|5.6 km||no exit|
|Noarlunga Centre, Christie Downs
|14.3 km||Noarlunga Centre, Christie Downs
|Old Noarlunga, Victor Harbor
Main South Road
|21.0 km||no exit|
|End Southern Expressway
Merges with Main South Road
|Start Southern Expressway
continues from Main South Road
The 15 bridges over the expressway from north to south are:
|2||Majors Road||O'Halloran Hill||Vehicle|
|3||Glenthorne Path||O'Halloran Hill||Foot|
|7||O'Sullivan Beach Road||Morphett Vale||Vehicle|
|8||Glenhelen Path||Morphett Vale||Foot|
|9||Flaxmill Road||Morphett Vale||Vehicle|
|10||Elizabeth Road||Morphett Vale||Vehicle|
|11||Beach Road||Morphett Vale||Vehicle|
Due to the duplication of the Expressway, all of the bridges have had to be widened to meet the new width of the road, with some road bridges being closed due to the work needed, and others requiring a lower speed limit for safety reasons. This has caused some anger with many southern residents and those that work in the area due to the longer routes and travel times required, with most of the work affecting the heavier populated areas around Morphett Vale and Noarlunga for well over 12 months from May 2012.
The expressway has five underpasses:
|2||O'Halloran Hill Recreation Park||O'Halloran Hill||Foot|
|3||Lander Road||Trott Park||Vehicle|
|5||Southern Expressway Southern terminus||Huntfield Heights||Bicycle|
Promotional FM radio transmitter
During its construction and for some time after its opening, the expressway was promoted via a dedicated FM radio station established by the Department of Transport broadcasting via a low-power FM transmitter in the immediate vicinity of the road. The radio station broadcast a recorded message on continuous loop featuring promotional and community information messages relating to the expressway, including a jingle that Transport Minister Diana Laidlaw declared made the expressway the only road in the world to have its own jingle.
- "New Southern Expressway freeway Darlington interchange scrapped". AdelaideNow. 22 August 2011. Retrieved 22 August 2011.
- "Southern Expressway". Government of South Australia. Archived from the original on 3 May 2013. Retrieved 3 November 2013.
- MATS plan freeways, ozroads.com.au
- PM's $100m pledge, Mark Kenny, The Advertiser, 18 August 2007.
- SA government News Release 17 February 2010
- The Hon. Sandra Kanck MLC. "Hansard 17 October 1995". Hansard of the Legislative Council of South Australia. Retrieved 2008-12-29.[dead link]
- Southern Expressway Traffic Management System Transport SA