M4 corridor bridge, serving Chepstow, being renumbered the M48, although the area is still generally considered as falling within the M4 corridor. Since the start of the 21st Century there has been evidence of more investment west of Cardiff, such as: M4 corridor The M4 corridor is an area in the United Kingdom adjacent to the M4 motorway, which runs from London to South Wales. It is a major high-technology hub. Important cities and towns linked by the M4 include (from east to west) London, Slough, Bracknell, Maidenhead, Reading, Newbury, Swindon, Bath, Bristol, Newport, Cardiff, and Swansea. The area is also served
M32 motorway opened by the Secretary of State for Transport, John Peyton in July 1970. The total cost was £3 million (now £ million). In 1972, a polystyrene storage depot on Muller Road near junction 2 caught fire, leading to the closure of the southbound M32 for six days. The third section was the most technically demanding, as it ran through heavily built-up urban areas and required numerous properties to be demolished, along with the "Thirteen-arch viaduct" near Stapleton Road that was built in 1874. Work was delayed owing to the Three-Day Week industrial action in 1974, and further because of a