M40 motorway

M40 motorway
mile	km	Southbound exits (B carriageway)	Junction	Northbound exits (A carriageway)	Coordinates
18.1	29.2	End of motorway Road continues as A40 to London	J1	Start of motorway Road formed from main carriageways of A40 from London	51.561305°N 0.495887°W / 51.561305; -0.495887 (M40, J1)
		Slough (A412) Uxbridge (A4020)		Amersham, Denham A40 Slough (A412) Non-motorway traffic
19.9 20.4	32.0 32.9	M25 Watford, (M1, M11) Heathrow , (M4, M3)	J1a	M25 Heathrow , (M4, M3) Watford, (M1, M11)	51.560798°N 0.531335°W / 51.560798; -0.531335 (M40, J1A)
24.8 25.3	39.9 40.7	Beaconsfield, Amersham, Slough A355, Beaconsfield services Extra	J2 Services	Beaconsfield, Amersham, Slough A355, Beaconsfield services Extra	51.594295°N 0.627637°W / 51.594295; -0.627637 (M40, J2)
27.8 28.1	44.7 45.2	No Exit	J3	High Wycombe (E) A40	51.603359°N 0.691710°W / 51.603359; -0.691710 (M40, J3)
31.3 31.6	50.3 50.9	High Wycombe, Marlow, Maidenhead A404 (M4)	J4	High Wycombe, Marlow A404 (M4)	51.612261°N 0.768485°W / 51.612261; -0.768485 (M40, J4)
38.9 39.3	62.6 63.2	Stokenchurch, West Wycombe A40	J5	Stokenchurch A40	51.660524°N 0.912895°W / 51.660524; -0.912895 (M40, J5)
		Entering Buckinghamshire		Entering Oxfordshire
41.4 41.8	66.7 67.2	Watlington, Princes Risborough B4009	J6	Watlington, Princes Risborough B4009	51.672236°N 0.96066°W / 51.672236; -0.96066 (M40, J6)
47.0 75.6	75.6 76.2	No Exit	J7	Thame, Wallingford, A329	51.724583°N 1.057477°W / 51.724583; -1.057477 (M40, J7)
48.0 48.4	77.3 77.9	No Exit	J8	Oxford, Cheltenham A40	51.732291°N 1.076832°W / 51.732291; -1.076832 (M40, J8)
49.0 49.2	78.9 79.2	Thame, Aylesbury A418 Oxford (A40) Oxford services Welcome Break	J8a Services	Aylesbury A418 Oxford (A40) Oxford services Welcome Break	51.740052°N 1.095457°W / 51.740052; -1.095457 (M40, J8a)
		Entering Oxfordshire		Entering Buckinghamshire
		Entering Buckinghamshire		Entering Oxfordshire
60.3 60.6	97.1 97.6	Bicester, Aylesbury A41 Oxford, Newbury A34	J9	Newbury, Oxford A34 Bicester A41	51.868754°N 1.198454°W / 51.868754; -1.198454 (M40, J9)
65.9 66.2	106.0 106.6	Northampton, Milton Keynes A43 Middleton Stoney B430, Cherwell Valley services Moto	J10 Services	Northampton A43 Middleton Stoney B430 Cherwell Valley services Moto	51.949635°N 1.206093°W / 51.949635; -1.206093 (M40, J10)
		Entering Oxfordshire		Entering Northamptonshire
		Entering Northamptonshire		Entering Oxfordshire
		Entering Oxfordshire		Entering Northamptonshire
		Entering Northamptonshire		Entering Oxfordshire
76.2 76.7	122.7 123.4	Banbury A422 (A361)	J11	Banbury A422 (A361)	52.072675°N 1.313295°W / 52.072675; -1.313295 (M40, J11)
		Entering Oxfordshire		Entering Warwickshire
		Entering Warwickshire		Entering Oxfordshire
		Entering Oxfordshire		Entering Warwickshire
86.8 87.0	139.7 140.0	Gaydon B4451	J12	Gaydon B4451	52.192219°N 1.458135°W / 52.192219; -1.458135 (M40, J12)
89.8	144.5	Warwick Services Welcome Break	Services	Warwick Services Welcome Break	52.218125°N 1.504269°W / 52.218125; -1.504269 (M40, Warwick Services)
92.1 92.3	148.2 148.6	No Exit	J13	Leamington, Warwick A452 (A425)	52.240678°N 1.553578°W / 52.240678; -1.553578 (M40, J13)
93.9 94.2	151.1 151.6	Leamington A452	J14	No Exit	52.256863°N 1.588211°W / 52.256863; -1.588211 (M40, J14)
95.0 95.3	152.9 153.4	Warwick A429 Stratford, Coventry, Warwick Parkway A46	J15	Coventry, Stratford, Warwick Parkway A46 Warwick A429	52.260068°N 1.613359°W / 52.260068; -1.613359 (M40, J15)
103.8 104.1	167.1 167.6	Henley A3400	J16	No Exit	52.335129°N 1.774549°W / 52.335129; -1.774549 (M40, J16)
105.7 106.0	170.1 170.6	Start of motorway Motorway is formed by two sliproads from the M42	J17 (M42, J3a)	End of motorway M42 The NORTH (M1, M6), Birmingham (E, N & C), Solihull, N.E.C, Airport & International The SOUTH WEST (M5), Birmingham (S & W), Redditch	52.347367°N 1.819139°W / 52.347367; -1.819139 (M40, End of motorway)

Data[8] from driver location signs are used to provide distance and carriageway identifier information. Where a junction spans several hundred metres, both start and end locations are given.

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

Junction 1 of the M40 is at the Denham Roundabout near Uxbridge just east of the M25. The motorway is carried over the top of the roundabout, which interchanges with the A40, the A412, the A4020 and links to the A413 off the A40 westbound.

The motorway carries on for another 1⁄2 mile (0.80 km) before it reaches J1a, the free-flow interchange with the M25 London Orbital. It is a partially unrolled cloverleaf, with the smoothest turns from the London-bound M40 (from Oxfordshire, Warwickshire and the wider West Midlands) to the anti-clockwise M25 (London Heathrow, Gatwick, The Channel Ports) and vice versa, since this is the largest exchange of traffic between the two motorways. The M40 passes over the interchange, with the M25 on the bottom. The clockwise M25 enters the junction with four lanes with a lane drop to accommodate traffic heading for the M40 westbound, leaving the junction with three lanes. The anti-clockwise M25 enters the junction with three lanes and gains a lane from the London-bound M40 to accommodate the extra traffic. The London-bound M40 enters with four lanes, with a lane drop for the M25 exit, leaves with three lanes, and the westbound M40 enters with lanes and gains a lane from the anti-clockwise M25.

After J1a the motorway is four lanes, and carries on for 3 miles (4.8 km) until it reaches J2 for the A355 to Slough and the A40 to Beaconsfield and Gerrards Cross. J2 is the standard roundabout interchange over the M40. Beaconsfield services are located at this junction.

J3 is 3 miles (4.8 km) further on, and serves the A40 for High Wycombe East and Loudwater. This is a restricted junction; the only flows are from the westbound M40 to the A40 and from the A40 to the London-bound M40. The westbound carriageway loses a lane, remaining three lanes for the rest of the route, and the London-bound carriageway gains a lane. The motorway then immediately crosses the valley on a large ramp-like bridge.

J4 is the interchange with the A404, for High Wycombe, Marlow, Maidenhead, Reading, Windsor and the M4. The motorway through the junction was not widened from the original two lanes when the rest of the motorway from J8 to London was, and so both carriageways experience a temporary lane drop. The junction used to be a straightforward roundabout interchange with exits for the M40 (west and east), High Wycombe (A404), the A4010, two local roads and the A404 dual carriageway to the south. During 2007, work was completed which included extra stacking space on the sliproads from the M40, provision for traffic from the A404 northbound to join the M40 westbound slip road without joining the roundabout and provision for the London-bound M40 to skip the section of the roundabout which serves the A4010, High Wycombe, and the A404 north.

Stokenchurch Gap cutting through the Chiltern Hills

J5 is for the A40 and Stokenchurch, a basic diamond interchange and the fourth junction of the M40 with the A40. Within a mile there is a large road cutting known as the Stokenchurch Gap or The Canyon where the motorway enters Oxfordshire and meets J6 with the B4009 for Lewknor, Watlington, and Chinnor. This junction is a variant on the diamond interchange, with the slip roads from the M40 having sharp bends. [9]

Just over 1 mile (1.6 km) after junction 6 the motorway passes to within 330 feet (100 m) of St Giles Church, Tetsworth and 2 miles (3.2 km) farther on meets the first of three junctions in close succession. Junction 7 is a restricted junction with the A329 serving Thame and the A40. Access is limited allowing exit for only northbound traffic and entry only for southbound traffic. The exiting slip road on the southbound M40 at J7 is for "Works Traffic Only" to a depot. A slip road allows traffic from the A329 to join the M40 north but is closed to motorway traffic by a gate, so traffic must continue for 2 miles (3.2 km)to junction 8.

At junction 8, a spur off the M40, with two-lane carriageways, leaves the mainline of the motorway as far as a trumpet junction for Wheatley and the A418, then continuing as the A40 towards Oxford. The spur can be accessed via the M40 northbound or by leaving the M40 at Junction 8a southbound and crossing the M40 via the A418, and traffic heading towards the M40 can only join the southbound carriageway. Traffic going in the other direction has to use the trumpet junction, and follow the A418 past Oxford services. The M40 heads north from junction 8A. This was the temporary end of the M40 before the northern section was open. Visible either side of the junction are the embankments and remains of the overbridge which carried the Wycombe railway line.

The motorway continues for 12 miles (19 km) t0 junction 9 for the A34 (E05) and the A41. The A34 dual carriageway serves Oxford and is a trunk route for Newbury, Winchester and Southampton (via the M3) as well as the rest of the South Coast — for this the reason it is part of the unsigned European route E05. The A41 dual carriageway serves Bicester and Aylesbury, and both roads meet the motorway at Wendelbury roundabout junction. This junction design is very inefficient and cannot cope with a very large volume of traffic using the junction. To try to alleviate this problem, there is a temporary lane drop for the London-bound carriageway. The largest exchange of traffic is between the A34 and the M40 north, and traffic on those roads backs up and causes congestion on both roads (going north and south), as well as on the interchange itself. North of the junction, the existing A34 becomes the A3400. This means the A34 is now technically in two halves (it regains status farther up the road at J16, although signs on the motorway do not mention this). Instead, the first signs for the A34 from a motorway are on the M42 at J4, as with the A41. The road also becomes part of the E05 north of J9.

The M40 follows a course of almost due north for 5 miles (8.0 km) before reaching Junction 10, for the Cherwell Valley services, the A43 and the village of Ardley. The A43 terminates at J10, although originally it carried on to Kidlington, the southern part of the old route now used by the re-routed A34. (The original A43 towards Oxford is now the B430.) The A43 serves Brackley, Silverstone and its racing circuit, home to the British Grand Prix. Farther on, the A43 leads to Northampton and the M1. Junction 10 was originally a dumbbell junction. The capacity of both the junction and the single carriageway A43 proved too small when the road was used as a freight thoroughfare from the congested M1 to the M40 to London, and the A34 at J9 to the south coast — in fact the 5 miles (8.0 km) stretch between these junctions is the busiest on the motorway in both directions. When the A43 (between the M1 and M40) was upgraded to dual carriageway, the junction was redesigned and rebuilt by the Highways Agency to cope with the extra traffic. A third roundabout was added to the junction, to the north, with the slips for the southbound M40 and the A43, with the slip roads for the northbound M40 remodelled as well, and the roundabout in the middle now serving the services.

The slip road for the London-bound carriageway which used to be accessed from the roundabout is now reached only via the services. The design and execution of the revised design of new junction is greatly derided, mostly because of the three roundabouts giving no priority to the main flow of traffic, (A43-M40 London), and the slip roads off and onto the motorway (except the one accessed via the services) have sharp turns and adverse cambers, which results lorries frequently tipping over and spilling their loads especially on the roundabout at the end of the northern carriageway. The junction fails to perform its function as an effective traffic junction. As well, the slip roads onto the motorway give little manoeuvring space as both join the motorway under (the same) bridge built for the old junction.[10]

The motorway then follows a winding route north for 10 miles (16 km) until Junction 11, the A422 and A361, serving Banbury. The motorway does not follow the straight route to the east of Middleton Cheney, meeting with the A422, as it had once been planned, due to a major landowner refusing his land to be cut in two. If built as planned, J11 would be east of Middleton Cheney, meeting with the A422, and probably would have fuelled major growth in the village as well as Banbury, the primary destination of the junction. As it is, the junction was built 1.5 miles (2.4 km) west along the A422, with the motorway skirting Banbury. The junction itself is a regular roundabout interchange, and has the single carriageway A361 from Daventry the dual-carriageway A422 from Brackley and the A43 from the west, and the dual-carriageway A422 (A361) toward Banbury feeding to/from it.

Another 12 miles (19 km) north-west along the motorway is Junction 12, serving Gaydon and the Heritage Motor Centre via the B4451. The junction is a box-standard diamond interchange. Farther along the motorway is Warwick Services, the last on the motorway, before it reaches the restricted access Junction 13. This serves Leamington Spa and Warwick via the A452, and Gaydon via the B4100. The junction is incomplete as a half-diamond interchange, with access only from the northbound carriageway and access to the southbound M40.

The junction is completed 2 miles (3.2 km) farther on at Junction 14, another restricted access junction, with access to the A452 from the southbound M40, and the access on to the motorway is in a northbound direction. The slip roads join at a roundabout and carry on as the single carriageway A452 to meet with the A452 to Leamington Spa, A425 to Warwick, and the A452 to J13. A few hundred yards further up is junction 15, known as Longbridge island. This is a large, regular roundabout interchange, and is always busy during peak times due to the various destinations it serves, including The Cotswolds, Stratford-upon-Avon, Coventry, and Warwick. Farther north, Henley-in-Arden (J16) is again 'incomplete' to discourage local traffic.

The motorway joins the M42 in both directions, with northbound traffic taking the left lane to exit eastbound, eventually forming the outer lanes of the M42 via a tight-bending two lane connecting road, and the right lanes being taken eastbound. Similarly, southbound, eastbound traffic from the M42 splits off from the outer two lanes, whereas westbound traffic of the M42 has a single lane, widening to a two lane slip road, which merges with the middle lane and forms the outer lane of the southbound M40.

The motorway has four service areas:

• Beaconsfield services (off J2), operated by Extra MSA accessible from the A355
• Oxford services (off J8A), operated by Welcome Break, accessible from J8 and the A418
• Cherwell Valley services (off J10, A43), operated by Moto. The first service station, opened in 1994 on the site of temporary toilet areas created when the motorway was constructed.[11]
• Warwick services (between J12 and J13), operated by Welcome Break, consisting of two sites mirroring each other without a connection.

M40 at Burtley Wood, Buckinghamshire

M40 at Warmington, Warwickshire

• Twelve school children and a teacher died when their minibus crashed into a parked motorway maintenance vehicle just after midnight on 18 November 1993. The inquest recorded a verdict of accidental death for all of the victims but noted that none of the children were wearing seatbelts and that the side-facing bench seating was dangerous. Seatbelts were subsequently made compulsory equipment on all coaches and minibuses, more than 20 years after they had been compulsory on cars. It has been compulsory for passengers to wear seatbelts on coaches and minibuses since 2006.[12]
• In 2002 more than 100 vehicles were involved in a pile-up near High Wycombe that resulted in two deaths.[13][14]
• On Friday 2 August 2002[15] four people were killed between J11 and J12, about 3 miles south of Warwick services, when a northbound lorry crossed the central reservation and into oncoming southbound traffic. The resulting fire caused the Southbound carriage to be closed for several hours and required resurfacing. The fatalities were named as Catriona Marvell, 31, from Brookside, Telford, Shropshire; Peter Thorpe, 41, from Wellington, Shropshire; Brian Sewell, 44, from West Bromwich, West Midlands, and David Hericourt, 44, from Hanwell, London. The inquest[16] was adjourned to a later date.
• Jimmy Davis, a 21-year-old Watford footballer on loan from Manchester United, died on the M40 in Oxfordshire in the early hours of 9 August 2003 after his BMW collided with a lorry. He was over the drink-drive limit and had been driving at up to 120 miles per hour (190 km/h).[17]
• A motor cycle rider was shot dead between J13 and J12 on 12 August 2007.[18][19] The victim was a member of the Hells Angels on his way home from the Bulldog Bash.[19] In October 2008, a man pleaded guilty to murder ahead of the trial of six other men on charges of murder and firearms offences.

• On 18 July 2012, a driver in her seventies died in a vehicle fire. She had broken down in the middle lane and a car collided with the back of her vehicle.[20][21]

• List of motorways in the United Kingdom
• M40 corridor
• History of Banbury, Oxfordshire

Wikimedia Commons has media related to M40 motorway.

• The Motorway Archive
  • Stokenchurch to Waterstock
  • In Buckinghamshire
  • Waterstock to Umberslade
• CBRD Motorway Database – M40
• Pathetic Motorways – A40(M) High Wycombe bypass
• Motorway Services Online – service stations on the M40.
• Seven Natural Wonders of the South