M3 motorway (Great Britain)

M3 shield
M3
MapM3 highlighted in blue

Shown with UK motorway network
Twyford down cutting 03.jpg
Looking south at Twyford Down
Route information
Part of E05
Maintained by National Highways
Length59 mi (95 km)
Existed1971–present
History
  • Opened: 1971
  • Completed: 1995
Major junctions
Northeast end
Major intersections
Southwest end
Location
CountryUnited Kingdom
CountiesSurrey, Hampshire
Primary
destinations
London
Bracknell
Aldershot
Basingstoke
Winchester
Southampton
Reading
Newbury
Road network
M2 M4

The M3 is a motorway in England, from Sunbury-on-Thames, Surrey, to Eastleigh, Hampshire; a distance of approximately 59 miles (95 km). The route includes the Aldershot Urban Area, Basingstoke, Winchester, and Southampton.

It was constructed as a dual three-lane motorway except for its two-lane section between junction 8 (A303) and junction 9. The motorway was opened in phases, ranging from Lightwater/Bagshot to Popham in 1971 to Winchester to Otterbourne Hill in 1995. The latter stages attracted opposition from environmental campaigns across Britain due to its large cutting through wooded Twyford Down; numerous road protests were held which delayed its opening. Similar protests were avoided on the near-parallel A3 by the construction of the Hindhead Tunnel. Since completion, the motorway has been an artery to the west and midsections of the South Coast and Isle of Wight including for tourism. The major settlements nearest to the motorway are served by a railway also used for commuting but are relatively dispersed. Traffic on the M3 sees delays and congestion on its busiest sections near commuting hotspots and during holiday periods. From Chertsey to Fleet the road was in 2017 converted to a Smart Motorway, turning the hard shoulder into a permanent fourth lane with emergency refuge lay-bys.[1]

  1. ^ "M3 gets first 'orange' smart motorway emergency area".