M20

A major artery from London to the Kent coast, the M20 is the UK's principal connection to continental Europe for freight traffic and tourists alike.

One of two parallel motorways crossing Kent from east to west, the M20 serves Maidstone and Ashford on its way to the coast, and is the faster and more direct road to Dover. It also directly serves the Channel Tunnel and has the M26 to link it directly with the southern flank of the M25. As a result, it's the more useful road for long distance traffic, while the M2 serves more local traffic to Medway and Thanet.

The importance of this corridor, ahead of the more important-sounding A2 and M2, dates back decades. Before the Second World War, one of the UK's earliest experiments in motorway building was going to be a bypass of Maidstone. The project was halted in 1939 before work could begin, but the intention was there for a faster way to the coast using the A20. In the 1950s, when special direction signs pointing to the Channel Ports were erected, using what was then a very novel green and white colour scheme, they sent traffic down the A20, avoiding the Medway Towns.

The pre-war plans for Maidstone were dusted off and, in 1961, the A20(M) Maidstone Bypass became one of the first motorways in the UK to open. As more motorway was built, it became part of the M20, and is now the section between junctions 5 and 8. The road was extensively widened and rebuilt in the early 1990s, so today almost nothing of the 1961 motorway remains to be seen.

By the 1980s progress was stalling because the worst trouble spots had been fixed. For many years, the M20 had a gap between Maidstone and Ashford, where the old A20 was a fast enough through route. It began to look like this would always be a motorway with a hole in it.

It was the Channel Tunnel that changed everything. It was realised that most people and freight coming through the Channel Tunnel would be driving off, not continuing by rail - especially since the onward rail link on the UK side only opened years after the tunnel itself. The pressure was on to get the M20 ready for its new purpose, calling for the massive upgrade work on the Maidstone Bypass and construction of the missing link between Maidstone and Ashford.

The M20 now runs from London all the way to Folkestone, and has a de facto extension in the form of the A20 to Dover. The gentle countryside of Kent allows it to be fast and direct, with the only demanding terrain on the route lying between junctions 1 and 3 where it climbs the South Downs.

Today it's a motorway of fickle temperament - fast and free flowing most of the time, but prone to horrendous problems and even total closures when special measures are taken during disruption to Channel ferry crossings. Operation Stack was the long standing plan that saw the motorway turned into a vast lorry park, but since 2019 that's been replaced with Operation Brock, and one of the UK's longest and most elaborate contraflow systems. There's never a dull moment on the M20.

Start

London

End

Folkestone

Passes

Maidstone, Ashford, Channel Tunnel

Connects to
Length

52 miles

Open Junctions Section
Dec 1960 J5-7 Maidstone Bypass West Opened as A20(M)
Sep 1961 J7-8 Maidstone Bypass East Opened as A20(M)
Dec 1971 J3-5 Ditton Bypass
May 1977 J1-2 Swanley → West Kingsdown
Feb 1980 J2-3 West Kingsdown → Wrotham
Oct 1981 J11-13 Sellindge → Folkestone
Dec 1981 J9-11 Ashford → Sellindge
May 1991 J8-9 Maidstone → Ashford

Exit list

Click any junction to see its full details.

Junction   Londonbound               Coastbound  
1
28.5 km
The NORTH (M1 Link, M11 Link)
Dartford Tunnel
The WEST
M25 Link
Swanley B2173
London A20


B2173

M25

A20
LONDON
A20


M25
LanesLanesLanesLanesLanes Signs LanesLanesLanesLanesLanes Signs
11 miles, 3 lanes 7 miles, 3 lanes
2
40.5 km


A227
A20
A20

A227

Paddock Wood
Wrotham
A20 (B2016)
Gravesend
Tonbridge
(A227)
LanesLanesLanesLanesLanes
  3 miles, 3 lanes
3
45.5 km
Gatwick (M23 Link)
Heathrow (M4 Link)
Sevenoaks (A25)
M26 Link (M25 Link)
M26
LanesLanesLanesLanesLanesLanes Signs LanesLanesLanesLanesLanesLanes Signs
3 miles, 4 lanes 6 miles, 4 lanes
4
50 km
West Malling
Rochester
Tonbridge
A228
A228 A228 West Malling
New Hythe
Rochester
A228
LanesLanesLanesLanesLanesLanes Signs LanesLanesLanesLanesLanesLanes Signs
5 miles, 4 lanes 3 miles, 4 lanes
5
54 km
Aylesford
(A20)


(A20)
Maidstone (W)
Aylesford
(A20)
LanesLanesLanesLanesLanesLanesLanes
LanesLanesLanesLanesLanesLanesLanesLanesLanes Signs
LanesLanesLanesLanesLanesLanes
LanesLanesLanesLanesLanesLanes Signs
2+3 lanes 2 miles, 2+3 lanes
6
56.5 km
Maidstone
Chatham
A229
A229

A229

Maidstone (C)
Chatham
A229
LanesLanesLanesLanesLanesLanesLanesLanesLanes
LanesLanesLanesLanesLanesLanes Signs
LanesLanesLanesLanesLanesLanesLanesLanesLanes
LanesLanesLanesLanesLanesLanesLanes Signs
2 miles, 4 lanes 2 miles, 4 lanes
7
59.5 km
Maidstone
Sittingbourne
Sheerness
A249
A249 A249 Maidstone
Sheerness
Canterbury
Ramsgate
A249
LanesLanesLanesLanesLanesLanes Signs LanesLanesLanesLanesLanesLanes Signs
4 miles, 3 lanes 4 miles, 3 lanes
8
65 km
Maidstone (E)
A20
Services Maidstone
(A20) Lenham
A20
Services Maidstone
LanesLanesLanesLanesLanes LanesLanesLanesLanesLanes
13 miles, 3 lanes 13 miles, 3 lanes
9
86.5 km
Ashford (W)
A20
Tenterden
Canterbury (A28)
Faversham A251
A20
(A28)
A251 Ashford
A20
Faversham
A251
LanesLanesLanesLanesLanes LanesLanesLanesLanesLanes
2.5 miles, 3 lanes 2 miles, 3 lanes
10
90.5 km
A292

A2070
A2070

A20
Ashford
A292
LanesLanesLanesLanesLanes
  0.5 miles, 3 lanes
10A
91.6 km
Hastings
Ashford
A2070
A2070 A20

A20
Hastings
A2070
LanesLanesLanesLanesLanes LanesLanesLanesLanesLanes
6.5 miles, 3 lanes 6.5 miles, 3 lanes
11
101.5 km
Canterbury
B2068
Hythe (A261)
Services Westenhanger
A20
(A261)
A20
B2068 Canterbury
B2068
Hythe (A261)
Services Westenhanger
LanesLanesLanesLanesLanes LanesLanesLanesLanesLanes
4 miles, 3 lanes 3 miles, 3 lanes
11A
106 km
Channel Tunnel
LanesLanesLanesLanesLanes
  1 miles, 3 lanes
12
107.4 km
Cheriton
Channel Tunnel
A20
B2064 A20 Cheriton
Channel Tunnel
A20
LanesLanesLanesLanesLanes LanesLanesLanesLanesLanes
1 mile, 2 lanes 1 miles, 2 lanes
13
109.4 km
A2034

A259






A20
COAST
Dover
Canterbury
Ramsgate
A20
Folkestone
A20
LanesLanesLanesLanes Signs LanesLanesLanesLanes Signs
Routes
M20

Picture credits

With thanks to James Harland, Alan Cottage, Paul Dawson, Scott Woodrow, Ritchie Swann, Andy Emmerson, James Armitage and Tom Sutch for information on this page.

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Published22 April 2017

Last updated8 March 2022