Adelaide's one-way expressway

Looking south at the beginning of the Expressway. The bridge in the foreground is across Marion Rd (A14). Jan 2005.

Length: 21km

Northern Terminus: Main South Road, Beford Park

Southern Terminus: Main South Road, Old Noarlunga

Route Markers: M2

Opened to traffic:

Stage 1 - 14 December 1997
Stage 2 - 9 September 2001

Overview and History:

The Southern Expressway is a unique one-way, reversible Expressway in Adelaide's south. It operates as a northbound roadway on weekdays between 2am and 1230pm and on weekends from 2pm to 1230am. It operates as a southbound roadway on weekdays from 2pm to 1230am and on weekends from 2am to 1230pm. The Expressway is designed purely to relieve congestion on Main South Road and Lonsdale Road at peak times.

The Expressway was constructed largely within the reservation of the North-South Freeway, proposed in the MATS plan of 1968.

In 1984, only one year after the death of MATS, the Government announced the intention to develop the 'Third Arterial Road', as it was then known, and planning and design work was commenced. In 1987 the project was split into two phases: Phase 1 - the upgrading of Main South Road and Marion Road around the Darlington area; and Phase 2 - a new road from Darlington to Reynella. At the time it was announced that Phase 2 would not be constructed until after 1993.

Phase one of the Third Arterial was complted 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 of the Third Arterial was included as an election policy of the Liberal Government which came to office in December 1993.

The announcement that Phase 2 of the Third Arterial would be replaced by the Southern Expressway came in March 1995 and it would be constructed in two stages: Stage 1 - from Darlington to Reynella, to be completed by the end of 1997; and Stage 2 - from Reynella to Old Noarlunga to be completed by the year 2000. The Government also announced that "because the demand for additional capacity is only for north-bound traffic in the morning and southbound traffic in the afternoon the road is being developed as a singel carriageway, one-way reversible road."8 Future duplication of the expressway would also be provided for in the roadworks base, and would be constructed when the need arises.

The proposed Southern Expressway would utilise the existing Noarlunga Freeway reservation, except for the northernmost kilometre, where a new route down the hill was chosen to provide high quality links with Marion and Main South Roads without cutting a swathe through Sturt.

Construction commenced on the Southern Expressway in July 1995 and the first stage, from Darlington to Reynella, was opened to traffic on 17 December 1997. The first stage has three lanes, the third of which splits of (southbound) at Reynella to join either Panatalinga Road or Main South Road.

Construction commenced on the second stage, from Reynella to Old Noarlunga, in February 1999. This 12km stage was opened to traffic on 9 September 2001, thus completing the Expressway to its original intent. Note: The MATS plan would have seen the expressway bypass Old Noarlunga and terminate just south of the Victor Harbour Road intersection. The Old Noarlunga Bypass was constructed in 1972 as Main South Road.

Further Reading (off-site):

Southern Expressway - Darrin Smith
Southern Expressway - Michael Greenslade

Photos of the M2 - Southern Expressway
Southbound on Main South Road in Bedford Park approaching the Southern Expressway. Jan 2005.
Advance Direction gantry signage with variable lane allocation messages. When the Expressway is closed a red "x" is shown. Jan 2005.
A little further down ther road, now we have quite a few turning lanes for the expressway. Jan 2005.
Looking south on the Expressway approaching Seacombe Road - which UBD incorrectly shows as going under the Expressway. Jan 2005.
1km to the Reynella Interchange (well technically its just an off-ramp or an on-ramp depending on the time, but what else would you call it?). Jan 2005.
Gantry signage at Reynella. This is the end of Stage 1 and the Expressway narrows to two lanes. Jan 2005.
Looking south through the Field River valley with the Young Street overpass in the middle ground. Jan 2005.
Sherriffs Road interchange. Jan 2005.
1km to Beach Road interchange. Jan 2005.
Beach Road offramp. Jan 2005.
1km to the end of the Expressway. Jan 2005.
Looking south to Main South Road at the southern end of the Expressway. Jan 2005.
Northbound on Main South Road at the southern end of the Southern Expressway. This is what the signs look like when the expressway is closed. Jan 2005.
Northbound on Main South Road at the Southern Expressway interchange, Reynella. The variable message sign says Southern Expressway/City when it is open. Jan 2005.

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