Pietermaritzburg, like most South African cities, uses metropolitan or "M" routes for important intra-city roads. These routes are a tier below national (N) roads and regional (R) roads. Each city's M roads are independently numbered.
In South Africa, Metropolitan or "M" routes are mostly used in metropolitan municipalities. Pietermaritzburg is the only exception, as it is not part of a metropolitan municipality yet still uses these road designations.