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 (Istanbul Metro) M4 (Istanbul Metro) The M4, officially referred to as the M4 Kadıköy–Tavşantepe metro line (), is a , 19-station rapid transit line of the Istanbul Metro. Running between Kadıköy and Tavsantepe, it is currently the only rapid transit line operating on the Asian side of Istanbul. The M4 mostly runs under State road D100, parallel to the Istanbul-Ankara railway and is entirely underground. The M4 opened on 17 August 2012 with a large ceremony in Kadıköy, in which Prime Minister Recep Tayyip Erdoğan personally took part in. On 29 October 2013, with the opening of Marmaray rail service under the