M40 motorway

M40
Route information
Part of E05
Maintained by National Highways
Length	89 mi (143 km)
Existed	1967–present
History	Opened: 1967 Completed: 1991
Major junctions
Southeast end	Denham
Major intersections	J1a → M25 motorway J17 → M42 motorway
Northwest end	Tanworth in Arden
Location
Country	United Kingdom
Counties	Buckinghamshire, Oxfordshire, Northamptonshire, Warwickshire
Primary destinations	London Uxbridge Beaconsfield High Wycombe Oxford Banbury Leamington Spa Warwick Birmingham
Road network
Roads in the United Kingdom Motorways A and B road zones
← M32 → M42

The M40 motorway links London, Oxford, and Birmingham in England, a distance of approximately 89 miles (143 km).

The motorway is dual three lanes except for junction 1A to junction 3 (which is dual four lanes) a short section in-between the exit and entry slip-roads at junction 4 (which is two lanes in both directions) and also between the slip-roads at junction 9 (in the south-eastbound direction only).

An Active Traffic Management system operates on the short section north-westbound from junction 16 (A3400) to the M42.