List of road routes in South Australia
Road routes in South Australia assist drivers navigating roads in urban, rural, and scenic areas of the state. Today, all numbered routes in the state are allocated a letter (M, A or B) in addition to a one, two or three digit number, denoting different levels of significance. The route system includes officially designated highways, urban freeways and arterial roads, and other important cross-state roads that have not been declared highways.
History
Route numbers have been allocated to South Australia's roads since 1955, with the introduction of National Routes across all states and territories in Australia, symbolised by a white shield with black writing; National Route 1 ('Highway 1') was one of the best-known numbered national routes, due to its fame for circumnavigating the continent.
In 1974, the National Highway network was defined, which allowed some existing National Routes to be upgraded to National Highways. These were marked with the same shield design as the National Routes, except for their gold-on-green colouring and the word NATIONAL added across the top. Unlike many other states, South Australia never adopted State Routes, although it allowed two Victorian rural State Routes to cross the border and terminate in locations within 20 km of it when they were rolled out there in 1985.
In 1998, the state replaced its system of National Routes and National Highways with an alphanumeric route numbering system. Many existing numbered routes were allocated a letter (M, A or B) in addition to its number, with 'M' routes denoting freeways, 'A' routes denoting routes of state significance, and 'B' routes denoting routes of local significance. Instead of shields, route numbers are displayed as yellow text on green rectangular backgrounds, and has now become the sole route numbering system in the state. The changeover to alphanumeric routes was carried out from 1998 either by removing old "shield" coverplates installed on newer signs, or installing new alphanumeric coverplates on old shielded signs, adopting the same design as Victoria (which adopted its alphanumeric system a year previous). Trailblazers were introduced with alphanumeric routes in Adelaide's metropolitan area and the tourist areas of Victor Harbor and the Barossa Valley in 1998,[1][2] with allocations extended to cover country areas in 1999.[3] Former National Highways still retained their shield design (including NATIONAL markings) after conversion, but were modified in 2017 to remove them, bringing their design in line with the rest of the state.
Alphanumeric Routes
All alphanumeric routes listed here are derived from the Government of South Australia's Location SA service.[4]
M routes
Roads allocated an M route are usually at least dual-carriageway motorways or expressways, with at least two lanes in each direction. These roads keep traffic moving and are likely to have no traffic lights and higher speed limits.[5]
| Route | Component roads | From | Via | To | Length | Notes |
|---|---|---|---|---|---|---|
 M1 | South Eastern Freeway | Glen Osmond | Murray Bridge | 69 km (43 mi) | Part of Highway 1: – western end re-aligned through Eagle on the Hill from Mount Barker Road to current alignment when freeway extension through the Heysen Tunnels opened in 2000 – continues north west as  along Glen Osmond Road beyond Adelaide– continues east as along Princes Highway to Tailem Bend– allocated  in 1998, progressively being replaced by  from 2017 | |
 M2 | Northern Expressway | Gawler | Hindmarsh | 51 km (32 mi) | Allocated in 2016 (replacing  ) | |
| Northern Connector | Allocated upon opening in 2020 | |||||
| North–South Motorway | – allocated  through Wingfield (replacing  ) when South Road Superway opened in 2014, progressively being replaced by  from 2017– extended south to Hindmarsh (replacing  ) when Torrens to Torrens section opened in 2018– to be extended further south eventually to Southern Expressway as further stages of the North–South Motorway are completed – continues south as along South Road to Southern Expressway at St Marys | |||||
| Southern Expressway | St Marys | Noarlunga Downs | 21 km (13 mi) | – southern end extended from Reynella to Noarlunga Downs when second stage opened in 2001 – northern end extended from Darlington to St Marys when Darlington bypass opened in 2020 – to be extended further north eventually to North–South Motorway as further stages are completed – continues north as along South Road to North–South Motorway at Hindmarsh | ||
 National Highway M20 | Northern Expressway | Virginia | Gawler | 22 km (14 mi) | Allocated upon opening in 2010, replaced by when Northern Connector commenced construction in 2016 | |
Decommissioned or unsigned route | ||||||
A routes
Roads allocated an A route are main or arterial routes providing a high standard of driving conditions both across single- or dual-carriageway roads, linking to and from M roads and provide access to major towns and places of interest across metro and regional SA.[5]
| Route | Component roads | From | Via | To | Length | Notes |
|---|---|---|---|---|---|---|
 A1 | SA/WA border | Medindie | 1,248 km (775 mi) | Part of Highway 1: – continues west as  along Eyre Highway into WA eventually to Norseman– discontinuous across the Adelaide city centre, partially  – allocated  in 1998, progressively being replaced by from 2017 | ||
| Eastwood | Frewville | Glen Osmond | 3.3 km (2 mi) | – discontinuous across the Adelaide city centre, partially – eastern end along Mount Barker Road terminating in Crafers truncated to current alignment when South Eastern Freeway extension through the Heysen Tunnels opened in 2000 – continues east as along South Eastern Freeway to Murray Bridge– allocated in 1998, progressively being replaced by from 2017 | ||
| Princes Highway | Murray Bridge | Swanport Bridge | Tailem Bend | 22 km (14 mi) | – continues west as along South Eastern Freeway to Glen Osmond – continues south as  along Princes Highway to Mount Gambier– allocated in 1998, progressively being replaced by from 2017 | |
| Princes Highway | Mount Gambier | SA/Vic border | 18 km (11 mi) | – continues west as along Princes Highway to Tailem Bend – continues east as along Princes Highway into Victoria eventually to Geelong | ||
 A2 | South Road | Hindmarsh | St Marys | 11 km (7 mi) | – allocated from Regency Park to Darlington (replacing  ) when South Road Superway opened in 2014– northern end truncated to Hindmarsh (replaced by ) when Torrens to Torrens section of North–South Motorway opened in 2018– southern end truncated to St Marys (replaced by ) when Darlington bypass of Southern Expressway opened in 2020– continues north as along North–South Motorway to Gawler– continues south as along Southern Expressway to Noarlunga Downs | |
 A3 | Cross Road | Plympton | Unley Park | Glen Osmond | 9.5 km (6 mi) | |
 A5 | Anzac Highway | Keswick | Plympton | Glenelg | 13.8 km (9 mi) | Northern end truncated from Adelaide to Keswick when City Ring Route re-aligned in 2017 |
 A6 |
| Mile End | Brooklyn Park | West Beach | 6.9 km (4 mi) | Eastern end truncated from Adelaide to Mile End when City Ring Route re-aligned in 2017 |
 A7 | Hindmarsh | Port Adelaide | 9.9 km (6 mi) | |||
 A8 | Dukes Highway | Tailem Bend | SA/Vic border | 192 km (119 mi) | – continues east as  along Western Highway into Victoria eventually to Beaufort– concurrency with  along Dukes Highway from Lowan Vale to Bordertown– allocated  in 1998, progressively being replaced by from 2017 | |
 A9 | Port Adelaide | Elizabeth Vale | 20.9 km (13 mi) | Eastern end extended along Salisbury Highway and John Rice Avenue from Dry Creek to Elizabeth Vale (replacing / ) when South Road Superway opened in 2014 | ||
 A10 | Gilberton | Houghton | 19.3 km (12 mi) | Continues east as  along North East Road to Nurioopta | ||
 A11 |
| Kent Town | Salisbury Heights | 25.1 km (16 mi) | Northern end re-aligned from Lower North East Road terminating in Houghton (replaced by  ) to current alignment in 2021 | |
 A13 | Darlington | Victor Harbor | 67.6 km (42 mi) | – allocation along South Road, Salisbury Highway and John Rice Avenue terminating in Elizabeth Vale truncated to current alignment (replaced by / and  ) when South Road Superway opened in 2014– concurrency with  along Victor Harbor Road through Willunga Hill– allocated along South Road through Wingfield in 1998, replaced by in 2014, progressively being replaced by from 2017 | ||
 A14 |
| Beverley | Darlington | 15.3 km (10 mi) | ||
 A15 | Alberton | Maslin Beach | 45.3 km (28 mi) | |||
| Southern end extended from Hallett Cove to Maslin Beach in 2021 | |||||
 A16 |
| Outer Harbor | Houghton | 37.5 km (23 mi) | ||
| Grand Junction Road | Allocated  (from Regency Park to Northfield) in 1998, progressively being replaced by from 2017 | |||||
| Lower North East Road | Eastern end extended along Lower North East Road from Hope Valley to Houghton (replacing  ) in 2021 | |||||
 A17 | Northfield | Payneham | Glen Osmond | 13.7 km (9 mi) | Allocated  in 1998, progressively being replaced by  from 2017 | |
 A18 | Paralowie | Parafield | Modbury | 12.5 km (8 mi) | ||
 A20 | Gepps Cross | SA/Vic border | 267 km (166 mi) | – continues east as  along Sturt Highway into Victoria through Mildura, and into New South Wales eventually to Tarcutta– allocated  in 1998, progressively being replaced by from 2017– western end along Main North Road terminating at Gepps Cross truncated to Gawler (replaced by  ) when Northern Expressway opened in 2010, reverted to in 2017 | ||
 A21 |
| Adelaide | North Adelaide | Adelaide | 15.6 km (10 mi) | Former City Ring Route, replaced by in 2017, listed clockwise from the western corner of Adelaide city centre |
 A22 |
| Gepps Cross | Kilburn | Ovingham | 7.7 km (5 mi) | |
 A32 | Barrier Highway | Giles Corner | SA/NSW border | 377 km (234 mi) | – continues east as  along Barrier Highway into New South Wales to Nyngan– concurrency with  along Barrier Highway through Burra | |
 A52 | Main North Road | Gepps Cross | Gawler | 32 km (20 mi) | Allocated when Northern Expressway opened (replacing ) in 2010, reverted to in 2017 | |
 A66 | Riddoch Highway | Keith | Mount Gambier | 210 km (130 mi) | Continues south as  along Riddoch Highway to Port MacDonnell | |
 A87 | Stuart Highway | SA/NT border | Port Augusta West | 928 km (577 mi) | – continues north as  along Stuart Highway into NT eventually to Daly Waters– allocated  in 1998, progressively being replaced by from 2017 | |
Decommissioned or unsigned route | ||||||
B routes
Roads allocated a B route are secondary or local arterial roads, These roads link to and from A and M roads and provide access to places of interest across metro and regional SA.[5]
| Route | Component roads | From | Via | To | Length | Notes |
|---|---|---|---|---|---|---|
 B1 | Princes Highway | Tailem Bend | Mount Gambier | 350 km (217 mi) | Part of Highway 1: – continues north as along Princes Highway to Murray Bridge– continues east as along Princes Highway into Victoria eventually to Geelong | |
 B10 |
| Houghton | Nurioopta | 73 km (45 mi) | – continues west as  along North East Road to Adelaide– concurrencies with:  along North East Road through Chain of Ponds; along Torrens Valley Road through Birdwood;  along Torrens Valley Road through Mount Pleasant | |
 B12 | Mallee Highway | Tailem Bend | SA/Vic border | 145 km (90 mi) | – continues east as  along Mallee Highway into Victoria eventually to Piangil– concurrency with along Mallee Highway through Pinnaroo | |
 B19 | Gawler | Lyndoch | Nuriootpa | 39 km (24 mi) | ||
 B23 | Main South Road | Old Noarlunga | Cape Jervis | 75 km (47 mi) | Route continues west over Backstairs Passage to Hog Bay Road on Kangaroo Island | |
| Penneshaw | Pelican Lagoon | Kingscote | 60 km (37 mi) | Route continues east over Backstairs Passage to Main South Road on the South Australian mainland | |
 B26 | Greenhill Road | Glenside | Uraidla | Balhannah | 24 km (15 mi) | Allocated in 2019 |
 B27 |
| Kent Town | Mount Torrens | 37 km (23 mi) | Allocated in 2019 | |
 B28 |
| Fullarton | Summertown | 25 km (16 mi) | Allocated in 2019 | |
 B29 |
| Unley | Clarendon | 27 km (17 mi) | Allocated in 2020 | |
 B31 |
| Campbelltown | Lyndoch | 49 km (30 mi) | Concurrency with along North East Road through Chain of Ponds | |
 B33 | Stirling | Strathalbyn | 37 km (23 mi) | |||
 B34 |
| Williamstown | Myponga | 109 km (68 mi) | Concurrencies with: along Victor Harbor Road through Willunga Hill; along Torrens Valley Road through Birdwood | |
 B35 |
| Mount Crawford | Murray Bridge | 63 km (39 mi) | Concurrency with along Torrens Valley Road through Mount Pleasant | |
 B36 |
| Palmer | Mannum | Murray Bridge North | 38 km (24 mi) | |
 B37 |
| Mount Barker | Delamere | 126 km (78 mi) | Concurrency with along Hindmarsh Road through Victor Harbor | |
 B45 |
| Strathalbyn | Langhorne Creek | Wellington East | 49 km (30 mi) | |
 B55 |
| Murray Bridge | Berri | 202 km (126 mi) | ||
 B56 |
| Winninowie | Peterborough | 108 km (67 mi) | Concurrencies with:  along RM Williams Way from Orroroo to Black Rock;  along Horrocks Highway through Wilmington | |
 B57 | Loxton | Cadgee | 292 km (181 mi) | Concurrencies with: along Dukes Highway from Lowan Vale to Bordertown; along Mallee Highway through Pinnaroo | ||
 B64 | Goyder Highway | Crystal Brook | Monash | 266 km (165 mi) | Concurrencies with: along Barrier Highway through Burra; along RM Williams Way through Spalding; along Horrocks Highway through Gulnare | |
 B66 | Riddoch Highway | Mount Gambier | Mount Schank | Port MacDonnell | 28 km (17 mi) | Continues north as  along Riddoch Highway to Mount Gambier |
 B77 |
| Two Wells | Gawler River | Gawler | 23.5 km (15 mi) | Allocated in 2021 |
 B78 | Wilkins Highway | Jamestown | Hallett | 38 km (24 mi) | ||
 B79 | Warnertown | Ucolta | 104 km (65 mi) | Concurrency with along RM Williams Way from Mannanarie to Jamestown | ||
 B80 | RM Williams Way | Hawker | Barinia | 220 km (137 mi) | Concurrencies with:  along RM Williams Way from Orroroo to Black Rock; along Goyder Highway through Spalding;  along RM Williams Way from Mannanarie to Jamestown | |
 B81 | Thiele Highway | Gawler Belt | Morgan | 115 km (71 mi) | ||
 B82 | Quorn | Gawler Belt | 282 km (175 mi) | Concurrencies with: along Wilmington–Ucolta Road through Wilmington; along Goyder Highway through Gulnare | ||
 B83 | Lyndhurst | Stirling North | 292 km (181 mi) | Much of this route still is signed  ;  shields still visible at Flinders Ranges Way and West Terrace intersection in Quorn | ||
 B84 |
| Port Wakefield | Eudunda | 100 km (62 mi) | ||
 B85 | Copper Coast Highway | Port Wakefield | Wallaroo | 58 km (36 mi) | ||
 B86 | Yorke Highway | Port Arthur | Stenhouse Bay | 181 km (112 mi) | ||
 B88 | St Vincent Highway | Pine Point | Warooka | 101 km (63 mi) | ||
 B89 | Spencer Highway | Port Pirie | Minlaton | 199 km (124 mi) | ||
 B90 | Tod Highway | Kyancutta | Uley | 176 km (109 mi) | ||
 B91 | Birdseye Highway | Elliston | Cowell | 198 km (123 mi) | ||
 B97 |
| Pimba | Olympic Dam | 89 km (55 mi) | ||
 B100 | Ceduna | Lincoln Gap | 715 km (444 mi) | |||
 B101 | Southern Ports Highway | Kingston SE | Millicent | 119 km (74 mi) | ||
 B160 | Glenelg Highway | Glenburnie | SA/Vic border | 15.3 km (10 mi) | Continues east as  along Glenelg Highway into Victoria eventually to Ballarat (a Victorian B route "extended" into SA) | |
 B201 |
| Barmera | Berri | Monash | 16.8 km (10 mi) | Former Sturt Highway alignment |
C routes
Roads allocated a C route are major collector roads, linking local roads and streets to the arterial road network for inter-state travel.[5]
While officially gazetted C routes exist in South Australia, these are currently based on existing Victorian C routes terminating in South Australian locations just inside the SA/Vic state border, and do not exist anywhere else in the state.
| Route | Component roads | From | Via | To | Length | Notes |
|---|---|---|---|---|---|---|
 C192 | Glenelg River Road | Mount Gambier | Wye | SA/Vic border | 30 km (19 mi) | Continues east as  along Glenelg River Road into Victoria to Portland |
 C198 | Casterton Road | Penola | SA/Vic border | 17.4 km (11 mi) | Continues east as  along Casterton–Penola Road into Victoria to Casterton | |
 C212 | Edenhope Road | Wrattonbully | SA/Vic border | 13.3 km (8 mi) | Continues east as  along Edenhope–Penola Road into Victoria to Edenhope | |
 C240 | Wimmera Highway | Naracoorte | SA/Vicborder | 23 km (14 mi) | Continues east as  along Wimmera Highway into Victoria to Marong |
R routes
Roads allocated a R route are for ring roads, provide a path around a city, rather than travelling through it.[5]
South Australia is currently the only state in the country to use R routes. To date, there is only one R route: around Adelaide, the state's capital city.
| Route | Component roads | From | Via | To | Length | Notes |
|---|---|---|---|---|---|---|
 R1 City Ring Route |
| Adelaide | North Adelaide | Adelaide | 16.9 km (11 mi) | Replaced  in 2017 on a slightly different alignment to the southwest, listed clockwise from the western corner of Adelaide city centre |
Former Routes
National Routes
National Routes were the first type of route numbering to be attempted in Australia on a large scale, signed with a white shield and black writing (similar in shape to the shield that appears on the Australian coat of arms), with South Australia receiving routes in 1955. They highlighted the interstate links connecting major population, industrial and principal regions of New South Wales to the rest of the Australia, in a way that was readily identifiable to interstate travellers. The system was prepared by the Conference of State Road Authorities, held between 1953 and 1954: once each state road authority agreed to the scheme, it was rolled out federally.
Selected routes were later upgraded into National Highways when the National Roads Act was passed in 1974.
South Australia's National Routes were eventually replaced with the alphanumeric system, introduced across the state between 1998 and 1999: each route was converted to an alphanumeric route number, rendering the black-and-white shield redundant. Most National Routes in rural South Australia kept their number during the conversion; two exceptions were National Route 47 (which became B83), and National Route 83 (which became B80, B82 and B83).
| Route | Component roads | From | Via | To | Length | Notes |
|---|---|---|---|---|---|---|
 National Route 1 | SA/WA border | SA/Vic border | 1,716 km (1,066 mi) | – progressively reallocated along South Eastern Freeway sections as they opened – replaced by from SA/WA border to Tailem Bend in 1974 | ||
| Princes Highway (II) | Replaced by: from Mount Gambier to SA/Vic border; from Tailem Bend to Mount Gambier in 1998 | |||||
 Alternate National Route 1 | Ceduna | Lincoln Gap | 715 km (444 mi) | Allocated after road sealing and upgrades of Flinders Highway completed in 1978, replaced by  in 1999 | ||
| Southern Ports Highway | Kingston SE | Millicent | 119 km (74 mi) | – former Princes Highway alignment (bypassed in 1933) – allocated in 1978, replaced by  in 1999 | ||
| White Hill | Murray Bridge | Long Flat | 13.2 km (8 mi) | Allocated when Swanport Bridge over the Murray River opened in 1979, replaced by  from White Hill to Murray Bridge East in 1998 | |
 National Route 8 | Dukes Highway | Tailem Bend | SA/Vic border | 192 km (119 mi) | Replaced by  in 1974 | |
 National Route 12 | Mallee Highway | Tailem Bend | SA/Vic border | 145 km (90 mi) | Replaced by in 1998 | |
 National Route 20 | Gepps Cross | SA/Vic border | 267 km (166 mi) | Replaced by  in 1992 | ||
 Alternative National Route 20 | Old Sturt Highway | Barmera | Berri | Monash | 16.8 km (10 mi) | Former Sturt Highway alignment, replaced by  in 1999 |
 National Route 32 | Gawler | SA/NSW border | 417 km (259 mi) | Replaced by in 1998 | ||
 National Route 47 | Flinders Ranges Way | Hawker | Quorn | Stirling North | 98 km (61 mi) | Replaced by  in 1998 |
 National Route 56 | Wilmington–Ucolta Road | Winninowie | Ucolta | 123 km (76 mi) | Replaced by in 1998 | |
 National Route 64 | Goyder Highway | Crystal Brook | Monash | 266 km (165 mi) | Replaced by in 1998 | |
 National Route 83 | The Outback Highway (Barndioota Road) | Lyndhurst | Giles Corner | 292 km (181 mi) | Replaced by in 1998 | |
| RM Williams Way | Replaced by in 1998 | |||||
| Main North Road | Replaced by in 1998 | |||||
 National Route 87 | Stuart Highway | SA/NT border | Port Augusta West | 928 km (577 mi) | Replaced by  in 1974 | |
Decommissioned or unsigned allocation | ||||||
National Highways
With the passing of the National Roads Act in 1974, selected National Routes were further upgraded to the status of a National Highway: interstate roads linking Australia's capital cities and major regional centres that received federal funding, and were of higher importance than other National Routes. These new routes were symbolised by green shields with gold writing, and the word "National" along the top of the shield. Most of South Australia's National Highways were declared in 1974 and their shields converted in the following years, with National Highway 20 later declared in 1992.
Like National Routes, South Australia's National Highways were also replaced with the alphanumeric system, introduced across the state in 1998: each route was converted to an alphanumeric route number, all keeping their number during the conversion, but also initially keeping the National green-and-gold shield design; this was eventually eliminated in 2017.
| Route | Component roads | From | Via | To | Length | Notes |
|---|---|---|---|---|---|---|
 National Highway 1 | SA/WA border | Tailem Bend | 1,716 km (1,066 mi) | – replaced by in 1998, being progressively replaced by from 2017 – Princes Highway (I) renamed Augusta Highway in 2011 | ||
| South Eastern Freeway | – progressively reallocated along South Eastern Freeway sections as they opened eventually to Murray Bridge in 1979 – replaced by in 1998, being progressively replaced by from 2017 | |||||
| Princes Highway (II) | Replaced by in 1998, being progressively replaced by from 2017 | |||||
 National Highway 8 | Dukes Highway | Tailem Bend | SA/Vic border | 192 km (119 mi) | – western end re-aligned from Tailem Bend to Coomandook through Cooke Plains in 1980 – re-aligned through Bordertown when Bordertown bypass opened in 1987 – replaced by in 1998, being progressively replaced by from 2017 | |
 National Highway 20 | Gepps Cross | SA/Vic border | 267 km (166 mi) | Replaced by in 1998, being progressively replaced by from 2017 | ||
 National Highway 87 | Stuart Highway | SA/NT border | Port Augusta West | 928 km (577 mi) | Replaced by in 1998, being progressively replaced by from 2017 | |
Decommissioned or unsigned allocation | ||||||
State Routes (from Victoria)
South Australia never adopted State Routes, but allowed two Victorian rural State Routes to cross the border and terminate in South Australian locations within 20 km of it when they were rolled out there in 1985; these were replaced by their Victorian equivalent alphanumeric allocations in 1998.
| Route | Component roads | From | Via | To | Length | Notes |
|---|---|---|---|---|---|---|
 State Route 112 | Glenelg Highway | Glenburnie | SA/Vic border | 15.3 km (10 mi) | Continued east as  along Glenelg Highway into Victoria eventually to Ballarat; replaced by in 1998 | |
 State Route 130 | Wimmera Highway | Naracoorte | SA/Vic border | 23 km (14 mi) | Continued east as  along Wimmera Highway into Victoria eventually to St Arnaud; replaced by  in 1998 | |
Decommissioned or unsigned route | ||||||
See also
- List of road routes in the Australian Capital Territory
- List of road routes in New South Wales
- List of road routes in the Northern Territory
- List of road routes in Queensland
- List of road routes in Tasmania
- List of road routes in Victoria
- List of road routes in Western Australia
- List of highways in South Australia