M3 is the main motorway from London to the south coast, linking Sunbury-on-Thames to Southampton. M3 passes through two counties from the South-East: Surrey and Hampshire. Primary destinations are Staines, Bracknell, Basingstoke and Winchester.
The M3 cover a distance of 59 miles (95 kilometers). It starts at Sunbury-on-Thames, in Surrey, on the edge of South West London, as a continuation of A316.