M3 motorway (Great Britain)

The M3 is a motorway between Sunbury-on-Thames and Southampton in England. It links London with Southampton and Portsmouth, as well as South West England. It is about 59 miles (95 km) long.

M3 motorway
Looking south at Twyford Down
Route information
Part of
Maintained by Highways England
Length	58.6 mi (94.3 km)
Existed	1971–present
History	Opened: 1971 Completed: 1995
Major junctions
Northeast end	Sunbury-on-Thames 51.4166°N 0.4240°W / 51.4166; -0.4240 (M3 motorway (northeastern end))
Major intersections	J2 → M25 motorway J14 → M27 motorway
Southwest end	Chilworth 50.9545°N 1.4081°W / 50.9545; -1.4081 (M3 motorway (southwestern end))
Road network
Roads in the United Kingdom Motorways A and B road zones
← →

Junctions

M3 motorway junctions
miles	km	North-east bound exits (B carriageway)	Junction	South-west bound exits (A carriageway)
15.0	24.2	Road continues as A316 to London	J1	Sunbury, Kingston A308 Non-motorway traffic
15.3	24.6	Sunbury, Kingston A308		Start of motorway
21.3	34.2	Gatwick Heathrow – M25 (M23), (M4)	J2	Gatwick, Heathrow (M23, M4) M25
28.1	45.2	Woking, Bracknell, Camberley, Bagshot, Lightwater A322	J3	Woking, Camberley, Bracknell, Bagshot, Lightwater A322
32.6	52.5	Guildford, Farnham, Camberley, Farnborough, Aldershot A331	J4	Guildford, Farnham, Camberley, Farnborough, Aldershot A331
34.4	55.4	Fleet (A3013), Farnborough (West) A327	J4a	Fleet (A3013), Farnborough (West) A327
		Fleet services (Welcome Break)	Services	Fleet services (Welcome Break)
41.9	67.4	Hook A287 B3349	J5	Hook A287 B3349
46.6	75.0	Basingstoke, Reading (A33), Alton A339	J6	Basingstoke, Newbury, Reading, Alton A339
51.8	83.3	Basingstoke A30	J7	Basingstoke A30
53.1	85.5	No access	J8	The South West, Andover, Salisbury, Exeter A303
59.9	96.4	Winchester services (Moto)	Services	Winchester services (Moto)
63.9	102.8	The Midlands, Newbury A34 trunk road Winchester A272, Alresford A31	J9	The Midlands, Newbury A34 trunk road Winchester A272
65.2	105.0	Winchester (City) B3330 Alton, Alresford A31	J10	No access
67.2	108.1	Winchester A3090 Twyford B3335	J11	Winchester A3090 Twyford B3335
70.0	112.6	Eastleigh (North) A335	J12	Eastleigh (North), Chandler's Ford A335
71.8	115.6	Eastleigh, Chandler's Ford A335	J13	Bournemouth M27(W) Eastleigh A335
		Start of motorway	J14	Southampton , Portsmouth M27(E) The West, Southampton Docks, Southampton A33
Notes Distances in kilometres and carriageway identifiers are taken from driver location signs/location marker posts. Where a junction goes across several hundred metres and the data is available, both the start and finish values for the junction are shown.
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

M3 Motorway (Great Britain) Media

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  M3 motorway at East Stratton

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  Southern end of the M3 meeting the A33 at Southampton

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  M3 motorway at Fleet

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  M3 under construction at Twyford Down