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.
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. 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.
B routes are routes that connect major settlements in the State but not eligible for A Rotes due to Road quality.
These are essentially roads that link minor settlements or areas that aren't eligible for an A or a B route.
There are three national highways and one current existing national route in the Northern Territory.
State routes are numbered based on their position in the territory, generally increasing in number from south to north.