M40 motorway

M40
M40
	M40 highlighted in blue ; Shown with UK motorway network
	Looking north at Warmington, Warwickshire, 2007
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
	; 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;

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.