Gawler Bypass is a major north–south route in the outer northern suburbs of the city of Adelaide, South Australia. It had the national designation of National Highway A20 north of the Northern Expressway, while south of this intersection it had the state designation of A52.[full citation needed] From late 2016, the entire length was designated A20, corresponding to the Northern Expressway being designated M2 (instead of M20).
It is a freeway standard route connecting Main North Road to the Sturt Highway, bypassing Gawler. Major exits include Angle Vale Road, Two Wells Road, Northern Expressway, Mallala Road and Horrocks Highway (formerly Main North Road). Each of these exits also have minor roads leading into Gawler.
The route was built in 1963 in an attempt to redirect traffic on the national highway out of Gawler town centre and has been upgraded and realigned several times since then.
The first Gawler bypass was planned in the 1950s and built as a single two-lane carriageway around the town in 1963 with at-grade intersections and carried 3,000 vehicles per day. It ended at a tee-junction at the southern end, and followed an alignment that included what is now the southbound on-ramp and Brereton Road, Jack Cooper Drive over the Winckel Bridge, and Paternoster Drive to the railway bridge.
The next advance developed the road to dual carriageway with grade-separated intersections at the southern end in the 1980s and new bridges over the Gawler River. When it was approved, the 1963 bypass was carrying 7000 vehicles per day, and 300 collisions had been recorded between 1977 and 1982.
The construction of the Northern Expressway in 2010 resulted in realignment of the northbound carriageway as part of creating a grade-separated intersection with smooth flow between the northern section of the Gawler bypass and both the Northern Expressway and the southern part of the Gawler bypass. As both roads lead broadly south, there is no provision to turn directly from one to the other.
Exits and interchanges
|Light||Hewett, Gawler Belt||0||0.0||Sturt Highway continues towards Nuriootpa, Mildura and Sydney|
|Horrocks Highway (Main North Road) – Roseworthy, Riverton, Clare / Main North Road – Hewett, Gawler|
|Thiele Highway (Also known as Freeling Road) – Kapunda, Eudunda, Morgan||via Main North Road|
|Gawler Belt, Willaston||1.5||0.93||Redbanks Road – Mallala, Balaklava / Gawler, Willaston||Also known as Mallala Road|
|Gawler Belt, Willaston, Reid||3.9||2.4||Morgan railway line|
|Ward Belt, Reid, Buchfelde||4.1||2.5||Northern Expressway – Adelaide, Port Adelaide||ramps on north side only|
|Reid, Buchfelde||4.6||2.9||Two Wells Road – Gawler West, Two Wells||ramps on north side only|
|Light, Gawler||Evanston, Evanston Gardens||Gawler River|
|Gawler||Evanston, Hillier||5.7||3.5||Jack Cooper Drive – Evanston, Evanston Gardens||south side ramps only|
|Evanston, Evanston Gardens||6.2||3.9||Gawler railway line|
|Evanston, Evanston Gardens, Evanston Park, Evanston South||7||4.3||Adelaide Road – Evanston, Gawler||continues as Main North Road|
- "Nearmap". Nearmap. 5 December 2010. Retrieved 5 December 2010.(subscription required)
- "Road Route Numbers (Trail Blazer)". Data SA. Government of South Australia. 8 November 2016. Retrieved 16 October 2017.
- "Main North Road By-Pass Altered". The Bunyip (5251). South Australia. 23 February 1951. p. 3. Retrieved 28 June 2016 – via National Library of Australia.
- Peter Morris, Minister for Transport Australia (9 May 1984). "$18 Million Gawler Bypass gets Go Ahead". Media Release. 71/84. Retrieved 28 June 2016.
- "NEW PLAN OF MAIN NORTH ROAD". The Bunyip (5237). South Australia. 3 November 1950. p. 1. Retrieved 28 June 2016 – via National Library of Australia.
- "Sturt Highway Upgrade". Department of Planning, Transport and Infrastructure. Retrieved 8 February 2017.
- "Property Location Browser". Department of Planning, Transport and Infrastructure. Retrieved 29 May 2015.