Road routes in the Northern Territory of Australia assist drivers navigating roads throughout the territory, by identifying important through-routes. The Northern Territory's National Highways are the main routes connecting Darwin to the adjacent states of Queensland, South Australia, and Western Australia. National Routes spur off the National Highways, and are other routes of national importance, while the remaining significant routes are designated as State Routes.^[1][2]

According to the Roads & Maritime Services, the Northern Territory has begun converting their numbered routes to alphanumeric routes, with a "progressive replacement" scheme that sees alphanumeric route markers introduced only when signs are replaced.^[3] The table below has a list of most signed alphanumeric routes.

Below are the existing alpha numeric routes as of November 2020. Even though the Northern Territory has been converting to alphanumerics for more than two decades, only four routes are fully signed, and a former State Route 23 that is missing a letter in all of its signs and just says "23". Signage in the Northern Territory is very inconsistent. For example C24 in not signed at the Stuart Highway junction but signed further into the route. Most signs were like this and as such very few routes have been signed in the Northern Territory.

A-Routes are major roads that link major destinations like Stuart Highway which connects Darwin to Adelaide.

Route	Component roads	From	To	Length	Notes
A1	Victoria Highway Stuart Highway	Daly Waters	WA–NT border (near Keep River National Park)	743 km (462 mi)	Continues east to Daly Waters as
	Stuart Highway	Darwin	Katherine	2,834 km (1,761 mi)	Partially signed as alphanumeric route ;[4] spur section connecting to Darwin. Note that this is a separate route from the A1 that goes from WA to Daly Waters
A3	Luritja Road	Petermann, Northern Territory	Watarrka National Park	161 km (100 mi)	Partially signed as A3[5]
A4	Lasseter Highway	Uluru	Erldunda	244 km (152 mi)	Partially signed as B4[6]
A15	Tiger Brennan Drive	Tivendale	Holtze	6.7 km[7] (4.2 mi)
A21	Kakadu Highway	Pine Creek	Kakadu	58.4 km (36.2 mi)
A36	Arnhem Highway	Mount Bundey, Northern Territory	McMinns Lagoon	78.4 km (49 mi)	Partially signed as alphanumeric route A36/B36[8][9]
A87	Stuart Highway	SA–NT border (near Kulgera)	Daly Waters	2,834 km (1,761 mi)	Has been partially signed as A87

B routes are routes that connect major settlements in the State but not eligible for A Rotes due to Road quality.

Route	Component roads	From	To	Length	Notes
B1	Carpentaria Highway	Daly Waters	Qld–NT border (near Wollogorang Airport)	380 km (236 mi)	Continues north from Daly Waters as National Highway 1 Has been partially signed as B1[10]
B6	Larapinta Drive	Watarrka National Park	Alice Springs	325 km (202 mi)	Partially signed as B6[9]
B11	Tablelands Highway	Tablelands	Cape Crawford	375 km (233 mi)	See here
B20	Roper Highway	Mataranka	Roper Bar	206 km (128 mi)	Partially signed as alphanumeric route B20[11]
B21	Kakadu Highway	Jabiru	Kakadu	150.6 km (93.5 mi)
B23	Dorat Road	Adelaide River	Hayes Creek, Douglas-Daly	65 km (40 mi)	Partially signed as 23[12] - It seems that the B is missing. Also there are no more State Route 23 signs, all of them have been replaced.[13]
B30	Litchfield Park Road Rum Jungle Road Batchelor Road	Blackmore	Coomalie Creek	145 km (90 mi)	[12]
B34	Cox Peninsula Road	Noonamah	Cox Peninsula	79.5 km (49 mi)	Partially signed as alphanumeric route B34[14]
B36	Arnhem Highway	Kakadu National Park	Mount Bundey, Northern Territory	148.6 km (92 mi)	Partially signed as alphanumeric route A36/B36
B96	Buntine Highway	Duncan Road, Nicholson, WA	Delamere	581 km (361 mi)	Has been fully signed[15] Partially unpaved

These are essentially roads that link minor settlements or areas that aren't eligible for an A or a B route.

Route	Component roads	From	To	Length	Notes
C5	Tanami Road	Burt Plain	WA–NT border (near Tanami)	1,035 km (643 mi)	Partially signed as C5[16] Partially unpaved
C12	Plenty Highway	Qld–NT border (near Tobermorey)	Burt Plain	496 km (308 mi)	Signs on the Alice Springs Golf Club Facebook page shows a C12 sign
C16	Barkly Stock Route Tablelands Highway Calvert Road	Lake Woods	Calvert	251 km (156 mi)	See here
C24	Central Arnhem Road	Bulman	Venn	663 km (412 mi)	Signage very inconstant[17] Partially unpaved
C80	Buchanan Highway	Victoria Highway (29.4 km (18 mi) south-east of Timber Creek	Birdum	393 km (244 mi)	Has been fully signed[18][19][20] Partially unpaved

There are three national highways and one current existing national route in the Northern Territory.^[1][2]

Current and former National Highways and Routes

Route	Planned alphanumeric route[21]	Component roads	From	To	Length	Notes
Routes that haven't been replaced with an Alphanumeric Route
National Highway 66	A2 or A66	Barkly Highway	Tennant Creek	Qld–NT border (near Ranken)	754 km (469 mi)
Routes that have been replaced with an Alphanumeric Route
National Highway 1	A1	Victoria Highway Stuart Highway	WA–NT border (near Keep River National Park)	Daly Waters	743 km (462 mi)	Mostly signed as alphanumeric route A1 Continues east from Daly Waters as B1
		Stuart Highway	Katherine	Darwin	2,834 km (1,761 mi)	Mostly signed as alphanumeric route A1;[citation needed] spur section connecting to Darwin
National Highway 87	A87	Stuart Highway	Daly Waters	SA–NT border (near Kulgera)	2,834 km (1,761 mi)	Mostly signed as A87 instead of National Highway 87
National Route 1	B1	Carpentaria Highway	Daly Waters	Qld–NT border (near Wollogorang Airport)	380 km (236 mi)	Continues north from Daly Waters as A1. Has been partially signed as B1.
Fully decommissioned National Routes
Former Route	Replaced alphanumeric route[21]	Component roads	From	To	Length	Notes
National Route 80	C80	Buchanan Highway	Birdum	Victoria Highway (29.4 km (18 mi) south-east of Timber Creek	393 km (244 mi)	Has been fully signed[18][19][20] Partially unpaved
National Route 96	B96 To Nicholson	Buntine Highway	Delamere	Duncan Road, Nicholson, WA	581 km (361 mi)	Has been fully signed[15] Partially unpaved

State routes are numbered based on their position in the territory, generally increasing in number from south to north.^[1]

Route	Planned Alphanumeric Replacement[21]	Component roads	From	To	Length	Notes
Routes that haven't been replaced with an Alphanumeric Route
State Route 2	B7	Namatjira Drive	Larapinta Drive, Hugh	Larapinta Drive, Namatjira	156 km (97 mi)
State Route 12	B12	Plenty Highway	Burt Plain	Qld–NT border (near Tobermorey)	496 km (308 mi)
State Route 14	C14	Sandover Highway	Plenty Highway, Anmatjere	Qld–NT border (near Alpurrurulam)	561 km (349 mi)	Unpaved
State Route 28	B28	Daly River Road Port Keats Road	Robin Falls	Wadeye	256 km (159 mi)	Not signed at all [citation needed]
Routes that have been replaced with an Alphanumeric Route
State Route 3	A3	Luritja Road	Lasseter Highway	Watarrka National Park	161 km (100 mi)	Partially signed as A3[5]
State Route 4	B4	Lasseter Highway	Erldunda	Uluru	244 km (152 mi)	Partially signed as A4/B4[6]
	C4	Tjukaruru Road Great Central Road	Uluru	WA–NT border (near Kaltukatjara)	189 km (117 mi)
State Route 5	C5	Tanami Road	Burt Plain	WA–NT border (near Tanami)	1,035 km (643 mi)	Partially signed as C5[16]
State Route 6	B6	Larapinta Drive	Watarrka National Park	Alice Springs	325 km (202 mi)	Partially signed as B6[9]
State Route 8	B8	Ross Highway Arltunga Road	Ross	Arltunga Historical Reserve, Hart	90 km (56 mi)
State Route 11	B11	Tablelands Highway	Tablelands	Cape Crawford	375 km (233 mi)
State Route 16	C16	Barkly Stock Route Tablelands Highway Calvert Road	Lake Woods	Calvert	251 km (156 mi)
State Route 20	B20	Roper Highway	Mataranka	Roper Bar	206 km (128 mi)	Partially signed as alphanumeric route B20[11]
State Route 23 – decommissioned	B23	Dorat Road	Adelaide River	Hayes Creek, Douglas-Daly	65 km (40 mi)	Partially signed as 23. However you will no longer be able to see a SR23 sign in the NT.
State Route 24	C24	Central Arnhem Road	Venn	Bulman	663 km (412 mi)	Signage very inconstant. Partially signed as C24.
State Route 30	B30	Batchelor Road Rum Jungle Road Litchfield Park Road	Coomalie Creek	Blackmore	145 km (90 mi)	Partially Signed[12]
State Route 34	B34	Cox Peninsula Road	Noonamah	Cox Peninsula	79.5 km (49 mi)	Partially signed as alphanumeric route B34[14]

• List of highways in the Northern Territory