M4 motorway M4 motorway The M4, a motorway in the United Kingdom running from west London to southwest Wales, was originally referred to as the London-South Wales Motorway. The English section to the Severn Bridge was constructed between 1961 and 1971; the Welsh element was completed in 1993. The Second Severn Crossing officially renamed the Prince of Wales Bridge, was inaugurated on 5 June 1996 by HRH The Prince of Wales and the M4 was rerouted. Apart from its two spursthe A48(M) and the M48the M4 is the only motorway in Wales. From London to Bristol, the M4 runs close to the
M4 relief road Cardiff University called for the decision to cancel the road to be overturned. In December 2011, the UK Chancellor of the Exchequer, George Osborne, announced that he would discuss options for improvements to the M4 with the Welsh Government, including the provision of additional finance which, it has been reported, could lead to the re-emergence of plans for a new M4 relief road. In February 2012 work started on a dual-carriageway road connecting Newport's southern distributor road to junction 23A of the M4 using part of the proposed route of the M4 relief road and a former access road to