The M3 is a motorway that runs from Sunbury-on-Thames, Surrey, to Southampton, Hampshire, a distance of approximately . Along with the A316, the M3 provides the main artery into South West London, as well as providing access to major towns and cities along its route, which include Winchester, Basingstoke, Southampton and the Aldershot Urban Area. From Junction 9 (A34) near Winchester, to Junction 14 (M27) on the northern fringe of Southampton, the M3 forms the southerly part of the unsigned E05. It was constructed as a dual three-lane motorway for most of its length, except for the two-lane section between Junctions 8 (A303) and 9. The motorway was opened in phases, with the first section (Junction 3 to 8) opening in 1971, and was eventually completed in 1995 upon the completion of the Junction 10 to 12 section. This faced widespread opposition due to the motorway being cut through the Twyford Down, numerous road protests were held during construction, which ultimately delayed its opening. Since then, the motorway has become a major artery to the South Coast, becoming a popular tourist route. As such the M3 faces regular delays and congestion on its busiest sections during rush hours and seasonal periods. The Junctions 2 to 4A section is currently being upgraded to a Smart Motorway, which will turn the hard shoulder into a fourth lane to provide extra capacity.