M4 motorway

M4
Prince of Wales Bridge looking towards Wales
Route information
Part of
Maintained by Highways England South Wales Trunk Road Agent
Length	189 mi[1] (304 km)
Existed	1963–present
History	Opened: 1959 (Chiswick Flyover), 1961 (as A4(M)), 1963, 1966 (as A48(M)) Completed: 1996
Major junctions
East end	Chiswick 51°29′23″N 0°16′41″W / 51.4897°N 0.2781°W / 51.4897; -0.2781 (M4 motorway (eastern end))
Major intersections	J4b → M25 motorway / J8/9 → A308(M) motorway/A404(M) motorway J10 → A329(M) motorway J19 → M32 motorway J20 → M5 motorway J21 → M48 motorway J22 → M49 motorway J23 → M48 motorway J29 → A48(M) motorway
To	Pont Abraham 51°44′42″N 4°03′54″W / 51.7451°N 4.0651°W / 51.7451; -4.0651 (M4 motorway (western end))
Location
Country	United Kingdom
Counties	Greater London, Berkshire, Wiltshire, Gloucestershire, Monmouthshire, Newport, Cardiff, Vale of Glamorgan, Rhondda Cynon Taf, Bridgend, Neath Port Talbot, Swansea, Carmarthenshire
Primary destinations	London London Heathrow Airport Slough Maidenhead Reading Newbury Swindon Bristol Newport Cardiff Bridgend Port Talbot Neath Swansea
Road network
Roads in the United Kingdom Motorways A and B road zones
← M3 M5 →

The M4 is a long motorway in the United Kingdom. It goes from London to South Wales. It also passes Bristol. It was first called the London–South Wales Motorway.

1. ↑ "Directions to M4, Hendy, Swansea". Google. Retrieved 11 February 2017.