M3 Motorway

The M3 Motorway

The M3 runs from Sunbury, across the M25 and through Surrey and Hampshire, past Basingstoke and Winchester to Southampton. It is the newest road in our network, with its own dedicated M3 website.

Our M3 Website

Everything you need for the M3 is on m3traffic.co.uk, updated every five minutes, 24 hours a day, from official National Highways data. It includes:

• the latest M3 traffic news
• accidents and incidents
• roadworks
• what the overhead signs are saying
• the variable speed limits in force now
• separate eastbound (towards London) and westbound (towards Southampton) pages
• closures tonight
• the M3 services
• M3 junction maps

It is one of a family of websites from UK Traffic News, each one given over to a single road so that the news you see is about the road you are actually driving.

About the M3 Motorway

The M3 motorway is 58.6 miles (94.3 km) long in the South of England. The M3 motorway runs from its Eastern end in Sunbury-on-Thames (A316) London to it south western end in Southampton.

Primary destinations at Staines, Bracknell, Basingstoke and Winchester.

The M3 links to the M25 at Junction 2 near London and to the M27 at Junction 14 Near Southampton. Situated south east of London.

The M3 was constructed between 1971 and 1995. Starting in Junctions 3 to 8 which were opened in 1971 Junctions 1 to 3 were opened in 1974, Junctions 12 to 14 in 1992 and Junctions 8 to 10 in 1995.

The first UK road to be built to motorway standard was the Preston Bypass which later became part of the M6.

UK Traffic News features traffic news and traffic updates and traffic reports from the main UK motorways including the M1, M2, M25, M3, M4, M40, M42, M5, M6, M60, M62, A1(M), motorways.

The M3 in numbers

Traffic on the M3 as counted by the Department for Transport.

about 82,000

vehicles a day

on an average stretch of the M3. The busiest stretch carries about 141,000 a day.

1 in 15

vehicles is a lorry

and about 1 in 6 is a van, so a large share of M3 traffic is people at work.

Source: Department for Transport road traffic statistics, 2025. Averages across the whole road; rounded.

See also: M3 traffic reports · all the motorways we cover.