The M20 is a

motorway A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway, and expressway. Other similar terms ...

Kent Kent is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Essex across the Thames Estuary to the north, the Strait of Dover to the south-east, East Sussex to the south-west, Surrey to the west, and Gr ...

, England. It follows on from the A20 at

Swanley Swanley is a town and civil parishes in England, civil parish in the Sevenoaks District of Kent, England, southeast of central London, adjacent to the Greater London boundary and within the M25 motorway periphery. The population at the 2021 ce ...

, meeting the M25, and continuing on to

Folkestone Folkestone ( ) is a coastal town on the English Channel, in Kent, south-east England. The town lies on the southern edge of the North Downs at a valley between two cliffs. It was an important harbour, shipping port, and fashionable coastal res ...

, providing a link to the

Channel Tunnel The Channel Tunnel (), sometimes referred to by the Portmanteau, portmanteau Chunnel, is a undersea railway tunnel, opened in 1994, that connects Folkestone (Kent, England) with Coquelles (Pas-de-Calais, France) beneath the English Channel at ...

and the ports at

Dover Dover ( ) is a town and major ferry port in Kent, southeast England. It faces France across the Strait of Dover, the narrowest part of the English Channel at from Cap Gris Nez in France. It lies southeast of Canterbury and east of Maidstone. ...

. It is long. Although not signposted in England, this road is part of the European route E15. It is also used as a holding area for goods traffic when traffic across the

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

is disrupted, such as

Operation Stack Operation Stack was a procedure used by Kent Police and the Port of Dover in England to park (or "stack") lorries on the M20 motorway in Kent when services across the English Channel, such as those through the Channel Tunnel or from the ...

and Operation Brock.

Route

The road starts at its junction with the

M25 motorway The M25 or London Orbital Motorway is a major ring road encircling most of Greater London. The 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 th ...

and A20 road just east of

, then continues south east across the River Darent, north of Farningham through the

North Downs The North Downs are a ridge of chalk hills in south east England that stretch from Farnham in Surrey to the White Cliffs of Dover in Kent. Much of the North Downs comprises two Area of Outstanding Natural Beauty, Areas of Outstanding Natural Be ...

, past West Kingsdown and

Wrotham Wrotham ( ) is a village on the Pilgrims' Way in Kent, England, at the foot of the North Downs. It is north of Borough Green and approximately east of Sevenoaks. It is between the M20 motorway, M20 and M26 motorway, M26 motorways. History T ...

to meet the M26. It then strikes east, running north of Addington. When it reaches junction 4 it passes south of

New Hythe New Hythe is a village in mid-Kent, England on the banks of the River Medway approximately northwest of the county town of Maidstone. It derives its name from the Old English word Hythe, meaning haven or landing place. It is split between the ...

and runs parallel to the Medway Valley railway line before crossing it close to junction 5. This next section is the

Maidstone Maidstone is the largest Town status in the United Kingdom, town in Kent, England, of which it is the county town. Maidstone is historically important and lies east-south-east of London. The River Medway runs through the centre of the town, l ...

bypass. The

High Speed 1 High Speed 1 (HS1), officially the Channel Tunnel Rail Link (CTRL), is a high-speed railway linking London with the Channel Tunnel. It is part of the line carrying international passenger traffic between the United Kingdom and mainland Euro ...

(HS1) railway line then runs parallel to the motorway as it continues to the north of Bearsted, crosses the Swanley to Ashford (via Maidstone East) line then out into the countryside alongside Leeds Castle. Proceeding south of Lenham and Charing it is crossed by the Ashford and HS1 railway lines before becoming the Ashford bypass. Travelling past

Brabourne Lees Brabourne Lees is a village in the civil parish of Brabourne, within the Ashford borough of Kent Kent is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Essex across the Thames Estuary to the ...

it is once again joined by HS1 and the East Stour. Just north of Saltwood it reaches the Channel Tunnel terminal and is crossed by HS1 for the last time. The final section runs along the northern

suburb A suburb (more broadly suburban area) is an area within a metropolitan area. They are oftentimes where most of a metropolitan areas jobs are located with some being predominantly residential. They can either be denser or less densely populated ...

s of Folkestone.

History

Construction

The M20 was, in common with many United Kingdom motorways, opened in stages: Junctions 5 to 7 opened in 1960. One end was near the 'Old England' pub on the A20 at

Hollingbourne Hollingbourne is a village and civil parishes in England, civil parish in the borough of Maidstone (borough), Maidstone in Kent, England. The parish is located on the southward slope of the North Downs to the east of the county town, Maidstone ...

Corner, junction 8, a temporary terminus until 1992, to the A229. It would be £1.5million for the eastern section , to open by the end of March 1960, built by Costain, designed by Scott Wilson. Work was started at Hollingbourne on Monday 5 May 1958 by Richard Nugent, Baron Nugent of Guildford, this was only five weeks after the M1 had started. It was one of three main motorway projects started in 1958. The section was intended to open on 27 March 1960, but was late. On Wednesday 1 June 1960, was opened at Forstal (A229) by Sir Leslie Doubleday, chairman of Kent County Council. Maidstone already had a bypass the A2011, which largely followed the A20(M) bypass. There was a short section of the A20(M) west of the A229 with a temporary terminus on the A2011. Junctions 7 to 8 opened in 1961 from the A229 to Coldharbour Lane. It was , to take 15months, planned for October 1960. The contract of £822,928 in March 1959 was given to Sir Robert McAlpine. Piles were constructed by West's Piling & Construction, of Harmondsworth. Work was started on Monday 13 April 1959 by Harold Watkinson near Cobtree Manor. The bridge across the Medway cost £200,000. The section opened on 3 December 1960. Coldharbour Lane was widened to , with a roundabout on the A20, with a terminus of the A20(M) north along Coldharbour Lane (junction 5). It was the south of England's first motorway. These sections of the M20 were known as the 'Maidstone Bypass'. This road was then numbered as the A20(M) as it bypassed the stretch of A20 through Maidstone which was renumbered A2020. This was the first stretch of motorway to open south of London. Plans for a bypass of Maidstone had existed since the 1930s, originally as an all-purpose project, before being upgraded to motorway standard in the 1950s. When the motorway was extended westwards towards London in the 1970s, it was renamed M20 and the A2020 reverted to A20. *Junctions 3 to 5 in 1971 *Junctions 1 to 2 in 1977. The West Kingsdown to Addington section was . It was constructed by Dowsett, with project manager Keith Haddock. The good weather in 1979 had helped :This section ended at a temporary junction near West Kingsdown. *Temporary terminus to junction 3 in 1980 this section of the route was difficult to construct due to its steep descent down the North Downs escarpment. *Sellindge to junction 13 in 1981 constructed by McAlpines *Junction 9 to Sellindge in 1981 constructed by Dowsett The section around Ashford (junctions 9–10) was originally the A20 Ashford Bypass with actual construction having started before World War 2 – although the route itself was not opened until 19 July 1957. The bypass started at Willesborough near the current location of junction 10 and terminated south of the existing junction 9 at the current Drover's Roundabout. A section of the old bypass is still visible now named Simone Weil Avenue. The original bridge that brought Canterbury Road over the bypass is still visible as the bridge was not reconstructed when the motorway was constructed. This section of motorway has no hard shoulder indicating the smaller width of the old bypass. This left the motorway in two sections, with the gap running via the A20 this was referred to locally as 'The Missing Link'. The level of traffic was not considered necessary to complete the route. Most of the traffic for the Channel ports was using the A2/ M2 route. When the

was ready for construction, it was decided to complete the M20 between junctions 8 and 9 and this opened in 1991. Concurrent to this was the extension to Dover as part of the A20 which opened in 1993. A new junction 11A was also constructed to serve the Channel Tunnel.

Operation

Following completion of the junction 8 to 9 section, the M20 was three lanes either side of the original A20(M) section. This was a

bottleneck Bottleneck may refer to: * the narrowed portion (neck) of a bottle Science and technology * Bottleneck (engineering), where the performance of an entire system is limited by a single component * Bottleneck (network), in a communication network * ...

, so it was decided to widen this section of motorway. The road here was increased to a dual three- or four-lane road with two-lane distributor roads either side. This section was opened in 1995. To the north of Maidstone, there is an overlap between the slip roads for junctions 5 (A20) and 6 (A229). Between 2006 and 2007, junction 10 near Ashford was remodelled to increase capacity when the bridges across the motorway were modified to provide three lanes of traffic at the roundabout, and local approach roads were widened, with new traffic lights to control traffic flows at the junction between the A292 Hythe Road and the London-bound M20 entry slip road. A new footbridge was also constructed across the motorway. The cost was £4.9 million. A Controlled motorway scheme was introduced in West Kent between junctions 4 and 7, with variable speed limits. In August 2016, part of a pedestrian footbridge connecting areas of Ryarsh divided by the motorway was brought down initially suspected to be the result of an impact by a digger from nearby works to widen the southbound bridge at junction 4 being carried on a low-loader that was moving along the hard shoulder. In the incident, the southern section of the bridge which rested on a plinth south of the motorway and the

cantilever A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...

ed northern section was dislodged and fell onto the carriageway below, landing on the trailer of a passing HGV and being narrowly avoided by a motorcyclist who suffered broken ribs taking avoiding action. Both carriageways of the motorway were closed to enable the removal of the broken section. The motorway reopened with the Highways Agency having declared that the northern part of the bridge was structurally intact. However this section of the motorway was again closed on the weekend of 3 and 4 September 2016 for the demolition and clearance of the northern bridge element. A replacement pedestrian and cycle bridge was opened in March 2021 at a cost of around £1.5 million. The

Highways Agency National Highways (NH), formerly Highways England and before that the Highways Agency, is a government-owned company charged with operating, maintaining and improving motorways and major A roads in England. It also sets highways standards u ...

proposed a new M20 junction 10a and link road to the A2070 at Ashford in Kent, east of junction 10, to support the development of South Ashford which has been identified as a growth area in the South East. In May 2012, it was announced that the scheme would be postponed for the short-term future. Planning recommenced in 2016. Work started on building the scheme in January 2018, with works planned to complete in May 2020. The coast-facing sliproads at the existing Junction 10 were closed to allow the final works on the London-facing sliproads at Junction 10a and the new junction opened on 31 October 2019.

Operation Stack and Operation Brock

Since the opening of the Channel Tunnel, sections of the M20 have been used occasionally for the implementation of Operation Stack, should the ferries and/or Channel Tunnel stop running. This closes that part of the motorway and uses the area as a lorry park until the ferries and/or Channel Tunnel are fully running again. Operation Brock was the replacement for Stack, to be used in the event of

no-deal Brexit A no-deal Brexit (also called a clean-break Brexit) was the potential Brexit, withdrawal of the United Kingdom (UK) from the European Union (EU) without a withdrawal agreement. Under Withdrawal from the European Union, Article 50 o ...

. In July 2020, the government announced that it had bought a site beside junction 10A to build the Sevington customs clearance facility and lorry park.

Junctions

Data from driver location signs are used to provide distance in kilometres and carriageway identifier information.Traffic England Live Traffic Condition Map
''Highways Agency'' – Locations extracted from Traffic Camera Popup identifier text Where a junction spans several hundred metres and start and end points are available, both are cited.

References

External links

The Motorway Archive – M20
{{DEFAULTSORT:M20 Motorway 2-0020 2-0020 Transport in the Borough of Ashford Transport in Folkestone and Hythe