Thorney Interchange | |
---|---|
Location | |
Buckinghamshire/Berkshire/Greater London | |
Coordinates | 51°29′42″N0°29′42″W / 51.495°N 0.495°W |
Roads at junction | |
Construction | |
Type | 4-level stack interchange |
Constructed | by Cementation Company and Costain Group |
Opened | 19 December 1985 |
Maintained by | National Highways |
The Thorney Interchange [1] is a large motorway intersection in the UK, between the M4 and M25. It is one of the busiest motorway interchanges in the country. It lies on the edges of Buckinghamshire, Greater London (London Borough of Hillingdon) and Berkshire, and is close to Surrey and Staines-upon-Thames.
The M4 (London-South Wales Motorway) in this area was opened in December 1964, from junctions 4 (A408) to 5; this 3.9-mile section cost £3.2m, and was built by Cubitts and Green. The interchange, therefore, is junction 4b of the M4.
The interchange is around one mile north-west of Heathrow Airport, and is the main junction for traffic heading from the M25 to the airport. The interchange is the point that the M4 enters Greater London.
The bridge decks were to be built of prestressed concrete, but instead were built with composite steel beams and concrete decks, designed to BS 5400. In the early 1980s, when the interchange was being built, the entire M25 was to cost around £600m.
The southern part of the M4/M25 interchange was part of a 2.05-mile section of the M25 which was due to open in spring 1985, the Poyle to Thorney Mill Road section, from junction 14 (Poyle Interchange) to junction 15. The £44m contract, given to the joint venture of Cementation/Costain, was to take three years. [2] The M25 section was due to be open nine months before the M4/M25 interchange would open. [3]
The northern section of the interchange was to be part of a 10.5-mile section of the M25 also due to open in spring 1985; this later became the 4-mile M4 to Iver Heath section to the M40, at Denham Interchange, junction 16. The 6.5-mile section of the M25 directly north of the M40 opened in January 1985.
Much of the M25 was designed by Halcrow Group. The interchange was designed by Atkins.
3.5m cubic metres of infill was needed for the contoured landscaping.
The section of M25 to the north began construction in April 1983. [4] Construction took 28 months, and cost £25m, with £10m for the fifteen bridges, by Wimpey Construction. The bridges were built to allow expansion to four lanes at a later date. The M25 was opened by Nicholas Ridley, Baron Ridley of Liddesdale on Wednesday 18 September 1985, as an 11-mile section directly south of the M40 to Poyle. The section had cost £80m. The M4/M25 junction was planned to open at a later date of June 1986, but it opened six months early, due to good weather, on Thursday 19 December 1985. At the time of opening two sections of the M25 remained to be completed in Hertfordshire and Kent (which opened in February 1986), and the M4/M25 junction was expected to be the busiest motorway junction in the UK. [5] [6]
It is a typical stack interchange. The part of the interchange that is north of the M4 is in Iver, in South Bucks. It is named after Thorney, Buckinghamshire, now part of Iver, the village in which the northern part of the interchange in situated. The part of the interchange that is south of the M4 is in Colnbrook with Poyle, in Slough. West Drayton and Harmondsworth are close to the east.
There are 11 bridges and three major viaducts, varying from 182m to 264m long. A 229m viaduct carries the M25 over the M4.
A single-track railway line passes through the middle of the interchange from north to south. [7] The only remaining section of the former Staines and West Drayton Railway, it carries freight to the Lakeside industrial estate south of the interchange,
The M25 or London Orbital Motorway is a major road encircling most of Greater London. The 117-mile (188-kilometre) motorway is one of the most important roads in the UK and one of the busiest. Margaret Thatcher opened the final section in 1986, making the M25 the longest ring road in Europe upon opening. The Dartford Crossing completes the orbital route but is not classed as motorway; it is classed as a trunk road and designated as the A282. In some cases, including notable legal contexts such as the Communications Act 2003, the M25 is used as a de facto alternative boundary for Greater London.
Colnbrook is a village in the Slough district in Berkshire, England. It lies within the historic boundaries of Buckinghamshire, and straddles two distributaries of the Colne, the Colne Brook and Wraysbury River. These two streams have their confluence just to the southeast of the village. Colnbrook is centred 3 miles (4.8 km) southeast of Slough town centre, 4 miles (6.4 km) east of Windsor, and 19 miles (31 km) west of central London.
The M4, originally the London-South Wales Motorway, is a motorway in the United Kingdom running from west London to southwest Wales. The English section to the Severn Bridge was constructed between 1961 and 1971; the Welsh element was largely complete by 1980, though a non-motorway section around Briton Ferry bridge remained until 1993. On the opening of the Second Severn Crossing in 1996, the M4 was rerouted over it.
The A41 is a trunk road between London and Birkenhead, England. Now in parts replaced by motorways, it passes through or near Watford, Kings Langley, Hemel Hempstead, Aylesbury, Bicester, Solihull, Birmingham, West Bromwich, Wolverhampton, Newport, Whitchurch, Chester and Ellesmere Port.
The M40 motorway links London, Oxford, and Birmingham in England, a distance of approximately 89 miles (143 km).
The M3 is a motorway in England, from Sunbury-on-Thames, Surrey, to Eastleigh, Hampshire; a distance of approximately 59 miles (95 km). The route includes the Aldershot Urban Area, Basingstoke, Winchester, and Southampton.
The A34 is a major road in England. It runs from the A33 and M3 at Winchester in Hampshire, to the A6 and A6042 in Salford, close to Manchester City Centre. It forms a large part of the major trunk route from Southampton, via Oxford, to Birmingham, The Potteries and Manchester. For most of its length, it forms part of the former Winchester–Preston Trunk Road. Improvements to the section of road forming the Newbury Bypass around Newbury were the scene of significant direct action environmental protests in the 1990s. It is 151 miles (243 km) long.
The M56 motorway serves the Cheshire and Greater Manchester areas of England. It runs east to west from junction 4 of the M60 at Gatley, south of Manchester, to Dunkirk, approximately four miles north of Chester. With a length of 33.3 miles (53.6 km), it connects North Wales and the Wirral peninsula with much of the rest of North West England, serves business and commuter traffic heading towards Manchester, particularly that from the wider Cheshire area, and provides the main road access to Manchester Airport from the national motorway network.
The A14 is a major trunk road in England, running 127 miles (204 km) from Catthorpe Interchange, a major intersection at the southern end of the M6 and junction 19 of the M1 in Leicestershire to the Port of Felixstowe, Suffolk. The road forms part of the unsigned Euroroutes E24 and E30. It is the busiest shipping lane in East Anglia carrying anything from cars to large amounts of cargo between the UK and Mainland Europe.
Iver is a large civil parish in Buckinghamshire, England. In addition to the central clustered village, the parish includes the residential neighbourhoods of Iver Heath and Richings Park and the hamlets of Shreding Green and Thorney.
South Bucks was one of four local government districts in the non-metropolitan county of Buckinghamshire, in South East England.
A directional interchange, colloquially known as a stack interchange, is a type of grade-separated junction between two controlled-access highways that allows for free-flowing movement to and from all directions of traffic. These interchanges eliminate the problems of weaving, have the highest vehicle capacity, and vehicles travel shorter distances when compared to different types of interchanges.
The A404 is a road in the United Kingdom that starts at Paddington in London and terminates near Maidenhead in Berkshire. It is 44.6 miles (71.8 km) long.
The Staines & West Drayton Railway (S&WDR) is a former railway on the western edge of London, England. It was about 5+1⁄2 miles (9 km) long and ran roughly north–south along the River Colne, parallel to the modern M25 motorway west of Heathrow Airport. It opened from West Drayton on the Great Western Main Line to Colnbrook in 1884 and reached Staines the next year.
The A40 is a major trunk road connecting London to Fishguard, Wales. The A40 in London passes through seven London Boroughs: the City of London, Camden, Westminster, Kensington & Chelsea, Hammersmith & Fulham, Ealing and Hillingdon, to meet the M40 motorway junction 1 at Denham, Buckinghamshire.
The Colne Brook is a river in England that is a distributary of the River Colne which runs from Uxbridge Moor, there forming the western border of Greater London, to the River Thames just below Bell Weir Lock in Hythe End, Wraysbury, Berkshire.
Transport in Buckinghamshire has been shaped by its position within the United Kingdom. Most routes between the UK's two largest cities, London and Birmingham, pass through this county. The county's growing industry first brought canals to the area, then railways and then motorways.
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The Borough of Slough is a borough with unitary authority status in the ceremonial county of Berkshire, Southern England. The borough is centred around the town of Slough and includes Langley. It forms an urban area with parts of Buckinghamshire and extends to the villages of Burnham, Farnham Royal, George Green, and Iver. Part of the district's area was in Buckinghamshire prior to the district's formation and in Middlesex until 1965.