M4 corridor 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 by the Great Western Main Line, including the South Wales Main Line, and London Heathrow Airport. Technology companies with major operations located in the area include Amazon, Citrix Systems, Dell, Alcatel-Lucent, Huawei, Lexmark, LG, Microsoft, Novell, Nvidia, O2, Panasonic,
M4 motorway Usk bridge two crossings (east/westbound) were added as a connection from the M4 (at the newly constructed junction 25a) to the north/southbound A4042 Heidenheim Drive. M4 motorway Usk bridge The M4 motorway Usk bridge (or St. Julians Bridge) carries the M4 motorway across the River Usk in the city of Newport in the United Kingdom. The bridge is actually two separate bridges for the eastbound and westbound carriageways. When travelling westbound, the bridges lead directly into the twin Brynglas Tunnels. Work commenced on both the bridge and the tunnels on 10 September 1962, two months after work commenced on the George Street