# A20 road (England)

The A20 is a major road in south-east England, carrying traffic from London to Dover in Kent. Parts of the route date back to turnpikes established in the early part of the 18th century. The line of the road throughout Kent runs closely in parallel with the M20 motorway.

## Route
### From London to the M25

Traffic leaving London at first takes the A2 road; at New Cross in the London Borough of Lewisham the A20 begins and heads in a south-easterly direction, becoming in turn Lewisham Way and Loampit Vale. The latter road forms a large junction, where the A21 separates for Bromley. The road now runs through Lee High Road into Eltham Road, The junction with the A210 has an unusually long 41 metre yellow box junction. and continues as the Sidcup Bypass, crossing the A222 at Frognal Corner and the A224 at Crittall's Corner. Entering Kent, it widens from two lanes to three lanes near Swanley and continues onto the M20 motorway.

#### Junctions

The main junctions on the London to M25 section are:
* New Cross one-way system (the road starts here and branches from the A2)
* Lewisham Gateway (with the A21, A2210 and A2211)
* Sutcliffe Park (with the A210 to Eltham) – the road becomes a dual carriageway east of this junction
* Clifton's Roundabout (with the A205 South Circular)
* Fiveways, New Eltham (with the B263); this is the last at-grade junction heading out of London
* Frognal Corner (with the A222)
* Crittall's Corner (with the A223 and A224)
* Swanley Interchange (M25 Junction 3 / M20 Junction 1)

### The M25 to Dover

The A20 then passes the racing circuit at Brands Hatch before descending steeply from the North Downs escarpment past Wrotham then West Malling and on to the county town of Maidstone. The route beyond Maidstone travels East, through the villages of Bearsted, Harrietsham, Lenham and Charing to Ashford.
The A292 takes over the former A20 through Ashford itself, then the road emerges as it heads through Willesborough and Sellindge in the direction of Hythe. It takes a sharp turn left at Newingreen (the site of the UK's first motel) before entering Folkestone via Cheriton, passing the vehicular entrance to the Channel Tunnel, forming part of the town's original bypass as the trunk road from the M20. The route then follows the coastline, tunnelling through the hills and descending to the docks in Dover, where it meets the A2 again coming down from Canterbury.

## History

Part of the route now followed by the modern road, particularly the western section, was opened as various turnpikes in the 18th century in an effort to improve coaching links between London and the Kent towns.
In the early days of the Great Britain road numbering scheme the A20 ran through Eltham, London. 0.7 miles (1.1 km) along Eltham Road the Sidcup Arterial Road begins, opened in 1923, which carries traffic south of the two towns instead, leaving the A210 and A211 roads following the original route. The nearby town of Swanley was bypassed in 1968, and the short link between the two bypasses was constructed in 1988 (to the south of the Ruxley Corner roundabout).
A section of the A20 in Ashford formed part of the Ashford By-Pass, a dual carriageway opened in 1957, which used to run from what is now the roundabout with Simone Weil Avenue to the Willesborough roundabout. Simone Weil Avenue is the original A20 bypass, but has been diverted to curtail at Canterbury Road. The eastern end of the old by-pass is now the M20.
The section between Maidstone and Ashford was the only link between the two separate sections of the M20 for 10 years during the 1980s, until the 14-mile (23 km) missing link of the motorway was completed in May 1991.
North of Folkestone the M20 becomes a dual carriageway and enters the Roundhill Tunnel before crossing over and dropping down into Dover. This part of the A20 was completed in 1993 as a project included in the Parliamentary Bill for the Channel Tunnel. During 2011, structural failures in and around the Roundhill Tunnel have caused the A20 to be closed in this area numerous times.

## Junction list
### A20

| County | Location | mi | km | Destinations | Notes |
| Greater London | Lewisham | 0.0 | 0.0 | A2 to A202 – Central London, Dover, Peckham | Western terminus |
| Greater London | Lewisham | 1.1– 1.2 | 1.8– 1.9 | A2210 north (Jerrard Street) – Deptford | Southern terminus of A2210 |
| Greater London | Lewisham | 1.3 | 2.1 | A21 south-east – Bromley, Catford | North-western terminus of A21 |
| Greater London | Lewisham | 1.4 | 2.3 | A2211 north – Greenwich | Southern terminus of A2211 |
| Greater London | London Borough of Lewisham–Greenwich boundary | 2.6 | 4.2 | A2212 south (Burnt Ash Road) / B212 (Lee High Road) – Grove Park, Blackheath | B212 and Blackheath signed westbound only; northern terminus of A2212 |
| Greater London | Greenwich | 3.2 | 5.1 | A210 east (Eltham Road) / A2213 north (Kidbrooke Park Road) to A205 north / A102 – Eltham, Kidbrooke, Docklands, Woolwich | To A205, A102, Docklands, and Woolwich signed eastbound only; western terminus of A210; southern terminus of A2213 |
| Greater London | Greenwich | 3.5 | 5.6 | A205 (South Circular) / A21 / A23 / A102 / A2 | To A102, A2, and Docklands signed westbound only |
| Greater London | Greenwich | 4.8 | 7.7 | A208 (Court Road) – Mottingham, Eltham | |
| Greater London | Bexley–Bromley boundary | 7.2– 7.7 | 11.6– 12.4 | A222 – Bromley, Chislehurst, Sidcup | Grade–separated junction |
| Greater London | Bexley–Bromley boundary | 7.9– 8.5 | 12.7– 13.7 | A224 / A223 north-east to B2173 – Orpington, Foots Cray, Bexley, Swanley | To B2173 and Swanley signed eastbound only; grade-separated junction; south-western terminus of A223 |
| Kent | Swanley–Farningham boundary | 12.0– 12.6 | 19.3– 20.3 | M25 / M20 east / B2173 – Gatwick Airport, Maidstone | Dover signed eastbound only; western terminus of M20; M25 junction 3; M20 junction 1 |
| Kent | Farningham | 13.9 | 22.4 | A225 north / Dartford Road – Dartford, Farningham, Sutton-at-Hone | Sutton-at-Hone signed westbound only; western terminus of A225 concurrency |
| Kent | Farningham | 14.3 | 23.0 | A225 south (Eynsford Road) – Eynsford, Otford, Sevenoaks | A225 and Sevenoaks signed westbound only; eastern terminus of A225 concurrency |
| Kent | Wrotham | 20.6 | 33.2 | A227 north (Gravesend Road) / Pilgrims Way – Gravesend, Meopham, Vigo | Western terminus of A227 concurrency |
| Kent | Wrotham | 20.9 | 33.6 | M20 west / A227 south to M25 – London, Swanley, Tonbridge, Borough Green | Eastern terminus of A227 concurrency |
| Kent | Wrotham | 21.8 | 35.1 | M26 to M20 / M25 / M23 / M4 – Maidstone, Dover, Gatwick Airport, Redhill | M26 junction 2a |
| Kent | Wrotham Heath | 22.2 | 35.7 | A25 west (Maidstone Road) – Sevenoaks, Platt, Borough Green | Eastern terminus of A25 |
| Kent | Leybourne | 25.7 | 41.4 | Ashton Way / Castle Way / Oxley Shaw Lane / A228 / M20 / A26 – Rochester, Tonbridge, Kings Hill, Leybourne | |
| Kent | Aylesford | 28.7 | 46.2 | Coldharbour Lane to M20 / A229 – Chatham | To A229 and Chatham signed eastbound only |
| Kent | Maidstone | 30.6– 30.8 | 49.2– 49.6 | A26 south-west (Tonbridge Road) – Tonbridge, Barming | North-eastern terminus of A26 |
| Kent | Maidstone | 30.9– 31.0 | 49.7– 49.9 | A229 north to M20 – Chatham | Western terminus of A229 concurrency |
| Kent | Maidstone | 31.5 | 50.7 | A229 south (Upper Stone Street) – Hastings, Shepway, Loose, Tovil | Shepway and Loose signed eastbound only, Tovil westbound only; eastern terminus of A229 concurrency; western terminus of A249 concurrency; southern terminus of A249 |
| Kent | Maidstone | 31.8 | 51.2 | A249 north to M20 / A229 – Sheerness, Chatham | Eastern terminus of A249 concurrency |
| Kent | Hollingbourne | 35.6 | 57.3 | M20 – London, Ashford | Destinations signed westbound only; M20 junction 8 |
| Kent | Charing | 44.3 | 71.3 | A252 east / School Road to A28 – Canterbury, Chilham, Challock | Challock signed eastbound only; western terminus of A252 |
| Kent | Ashford | 49.4 | 79.5 | A28 (Templer Way / Simone Weil Avenue) / A292 (Maidstone Road) – Canterbury, Tenterden, Ashford, Great Chart | North-western terminus of A292 |
| Kent | Ashford | 49.8– 50.2 | 80.1– 80.8 | M20 west / A251 north – London, Maidstone, Faversham, Kennington | Kennington signed eastbound only; western terminus of M20 concurrency; southern terminus of A251; M20 junction 9 |
| Kent | Willesborough | 52.4– 53.0 | 84.3– 85.3 | M20 east / A2070 / A292 north-west to A28 – Dover, Folkstone, Ashford, Hastings, Canterbury | Eastern terminus of M20 concurrency; south-eastern terminus of A292; M20 junctions 10-10A |
| Kent | Newingreen | 59.4 | 95.6 | A261 south-east (Hythe Road) to A259 – Hythe, Hastings | North-western terminus of A261 |
| Kent | Postling | 60.5 | 97.4 | M20 / B2068 – Ashford, London, Folkestone, Dover, Canterbury, Stanford (north) | Direct access eastbound only; M20 junction 11 |
| Kent | Newington | 63.2 | 101.7 | Channel Tunnel | No access eastbound |
| Kent | Folkestone | 64.7 | 104.1 | M20 west / Cheriton High Street – Ashford, London, Cheriton, Folkestone | Folkestone signed westbound only; western terminus of M20 concurrency; M20 junction 12 |
| Kent | Folkestone | 65.5– 66.1 | 105.4– 106.4 | Folkestone | Eastern terminus of M20 concurrency; eastern terminus of M20; M20 junction 13 |
| Kent | Folkestone | 66.4 | 106.9 | Roundhill Tunnel | Roundhill Tunnel |
| Kent | Hawkinge | 66.7– 67.2 | 107.3– 108.1 | A260 – Canterbury, Folkestone | Grade–separated junction; Folkestone signed westbound only |
| Kent | Hougham Without | 69.8– 70.4 | 112.3– 113.3 | B2011 – Capel-le-Ferne, West Hougham | Grade–separated junction |
| Kent | Dover | 73.8– 74.0 | 118.8– 119.1 | A256 north (York Street) – Town centre | A256 signed westbound only, Town centre eastbound only; southern terminus of A256 |
| Kent | Dover | 74.4 | 119.7 | A2 west / Port of Dover – Canterbury, Deal, Ramsgate, Sandwich | Eastern terminus; eastern terminus of A2 |
| Dover ||||||