Numbered routes in South Africa

In South Africa some roads are designated as numbered routes to help with navigation. There is a nationwide numbering scheme consisting of national, provincial and regional routes, and within various urban areas there are schemes of metropolitan route numbering.

In the nationwide numbering scheme, routes are divided into a hierarchy of three categories: national routes, which are the most important routes connecting major cities; provincial routes, which connecting smaller cities and towns to the national route network; and regional routes, which connect smaller towns to the route network. Route numbers are allocated to these classes as follows:

These numbers are allocated by the Route Numbering and Road Traffic Signs Sub Committee within the Roads Co-ordinating Body, an organisation which contains representatives from road authorities in national, provincial and local government.

In metropolitan numbering schemes the local authority can designate routes consisting of M followed by any number, but it should not use numbers the same as those used by national, provincial or regional routes in the same area. This rule is not universally followed, for example in Johannesburg where there is both an N1 and an M1.

The following cities have metropolitan numbering schemes

...
Wikipedia