A48(M) motorway
Road in Wales
From Wikipedia, the free encyclopedia
The A48(M) is a motorway in Wales that links Cardiff with Newport. It is a 2-mile-long (3 km) spur of the M4 motorway. At St Mellons, it runs continuously into the dual-carriageway A48, which also has (albeit narrow) hard shoulders. The A48(M) has no other junctions and opened in 1977.[1] The M4 was extended west from junction 29 in 1980.[2]
.svg)
| ||||
|---|---|---|---|---|
 A48(M) highlighted in blue | ||||
,_looking_east_near_Castleton.jpg) North-Eastbound heading towards M4 junction 29 | ||||
| Route information | ||||
| Maintained by South Wales Trunk Road Agent | ||||
| Length | 2.0 mi (3.2 km) | |||
| Existed | 1977–present | |||
| Major junctions | ||||
| Northeast end | Castleton, Newport | |||
  J29 → M4 motorway | ||||
| Southwest end | St Mellons, Cardiff | |||
| Location | ||||
| Country | United Kingdom | |||
| Counties | Newport, Cardiff | |||
| Primary destinations | Cardiff | |||
| Road network | ||||
| ||||
Junctions
| North-Eastbound exits | Junction | South-Westbound exits |
|---|---|---|
| M4 London |
J29 M4 (Castleton) | Start of motorway |
| Entering the City and County Borough of Newport | Entering the City and County of Cardiff | |
| Start of motorway Newport |
J29A (St Mellons) | A48 Cardiff |
Previous A48(M) motorways
The 6-mile (9.7 km) Port Talbot bypass which opened in 1966,[1] was numbered A48(M) before its incorporation into the westward extension of the M4 in the 1970s.[citation needed] Some maps show the Morriston bypass section of the M4 as also having been originally numbered A48(M), although whether this number was ever used on the ground has been questioned.[citation needed]