Inner ring route
The Inner Ring Route is a collection of major roads signposted as state route R1 (was A21 before 2017). There are no grade-separated intersections on the ring. Listed clockwise from Main North Road, the inner route consists of:
- Robe Terrace
- Park Road (Southbound)
- Mann Terrace (Northbound)
- Hackney Road
- Dequetteville Terrace
- Britannia Roundabout
- Fullarton Road
- Greenhill Road
- South Road
- James Congdon Drive
- Port Road
- Park Terrace
- Fitzroy Terrace
The Inner Ring Route is adjacent to the outer edge of the Adelaide Park Lands except on the western side between Anzac Highway and Port Road where railway lines occupy the space along the parklands, and the road ring route is further out. The earlier A21 route using West Terrace passed inside the ring of parklands instead.
Prior to the renumbering as route R1 in 2017, the western side of the previous route A21 was different to the current route. It followed moore of Port Road southeast, West Terrace and Goodwood Road. Route R1 uses James Congdon Drive, a short section of South Road and instead.
The Park Terrace section had a level crossing of the Outer Harbor railway line until 2017. The crossing was replaced by a bridge when the railway was lowered as part of a project to separate the Torrens Junction so that suburban trains to Outer Harbor did not conflict with interstate trains on the standard gauge line.
The Park Terrace bridge over the Gawler railway line and interstate freight line was constructed in 1990. When it was built, it replaced an awkward 30-degree level crossing. In 2017, it was named after the engineer who supervised its construction, David Fitzsimons.
Outer ring route
The Outer Ring Route is not signposted. It also consists of major roads surrounding the city. They are:
- Department of Planning, Transport, and Infrastructure (24 August 2004). "Adelaide's Inner and Outer Ring Routes". Government of South Australia. Archived from the original on 6 March 2014. Retrieved 22 December 2013.CS1 maint: multiple names: authors list (link)
- "Road Route Numbers (Trail Blazer)". Data SA. Government of South Australia. 8 November 2016. Retrieved 16 October 2017.
- Department of Planning, Transport, and Infrastructure (13 August 2004). "Adelaide's Inner & Outer Ring Routes Map". Government of South Australia. Retrieved 22 December 2013.CS1 maint: multiple names: authors list (link)
- Google (11 December 2016). "Adelaide city and inner ring route" (Map). Google Maps. Google. Retrieved 11 December 2016.
- Kemp, Miles (26 December 2017). "Olympic Hero's name to span across the ages". The Advertiser.
- "Property Location Browser". Government of South Australia. Retrieved 19 October 2017.
- Google (19 October 2017). "City Ring Route R1, Adelaide" (Map). Google Maps. Google. Retrieved 19 October 2017.