Great Britain road numbering scheme

In Great Britain, roads are given a letter with 1–4 numbers after it. This is how they are named. The letter is the category of the road. There are two main types of categories: motorways (with the letter M) and non-motorways. There are two types of non-motorways: A roads (with the letter A) and B roads (with the letter B). A roads are more important than B roads. There are also a very small number of C roads.

This system only applies to the island of Great Britain. Northern Ireland and other islands have their own systems.