A48(M)

A48(M)

Castleton
to
St Mellons

The A48(M) is a little spur from junction 29 of the M4 to let traffic flow more smoothly between Cardiff and the Severn Bridges.

Routes

M4 Newport Relief Road 8 March 2017

Construction of a new dual three-lane motorway to the south of Newport, from junction 23 of the existing M4 to junction 29, in order to replace the existing motorway which suffers severe operational and congestion problems.

This solution has been chosen partly because widening the M4 and bringing it up to modern standards would be prohibitively difficult - in particular with regard to the Brynglas Tunnels and the twisting alignment.

Routes
Region