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Location Map ( geo)
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From:  Lewisham (TQ382758)
To:  Hastings (TQ816093)
Distance:  58.6 miles (94.3 km)
Meets:  A20, A205, M25, A25, A26, A28, A259
Primary Destinations
Highway Authorities

National Highways • Transport for London • East Sussex

Traditional Counties

Kent • Sussex

Route outline (key)
A21 Lewisham - Locksbottom
A21 Locksbottom - Badgers Mount
(M25) Badgers Mount - Chevening
A21 Chevening - Hastings


The A21 is the main arterial route out of London for traffic wishing to head to Hastings. Upgraded piecemeal over the years there are still large parts of it that are unimproved and it is nowhere near the quality of the M23/A23 route to nearby Brighton. .


Looking north at the former A21 roundabout terminus in Lewisham

Section 1: Lewisham - Chevening

The A21 begins at a signalised junction with the A20 by Lewisham Station. This was a roundabout until 2016. It trundles down to Catford, where it gets tangled up with the South Circular. This one-way system is called the Catford Gyratory. The road then heads out through the increasingly leafy suburbs, and into Bromley. There's a new bit of dual carriageway spine road which bypasses the High Street - with traffic lights for the A222. This is called Kentish Way though it starts on the cutely named Tweedy Road. The dual carriageway ends at a set of lights with the B228 and the passes through Bromley Common, and the first bit of open space. After a couple of miles it reaches Farnborough Common, and the junction with the A232, called "The Fantail", which dumps traffic from Croydon onto the A21. The terminating A232 passes its primary status onto the A21. Having just come through miles of suburbs, Farnborough itself has a bypass, but is single carriageway. Then the A223 is met at a roundabout.

After another roundabout, the A21 deviates slightly from its original course, and runs north of the railway and Knockholt station rather than south - this is another minute bit of dual carriageway. At the next roundabout, with the A224 the A21 disappears, leading onto a spur of the M25. The spur leads to junction 4 of the M25, where, if traffic wishes to find the A21 again, it needs to head southbound on the main M25 to junction 5 at Chevening. Like the A264 the A21 gets to multiplex with a motorway.

A21 Motorway Spur, coming from the M25

Section 2: Chevening - Pembury

If you are using the M25 to get back onto the A21, as you are directed to do, you have to 'come off' at J5, the Chevening Interchange. Although to access the southbound A21 from the M25 you need only stay on the main carriageway - to continue on the M25 westbound you need to use the slip road as for M25 traffic this is a TOTSO. There's no access to the M26 eastbound. After the junction, the road is still classified as M25 up to the GSJ with the A25. Then it is back to the A21 classification and trunk road status is gained.

The Sevenoaks bypass is unadulterated two-lane grade-separated dual carriageway. There are some good views of the Weald, too. There is a junction with the old A21 - now the A225 and B245 (a rare sighting of a 3-digit 'B' road outside London) - where the Sevenoaks bypass becomes the Tonbridge bypass. The bypass a couple of interestingly shaped junctions with the A26, and multiplexes with it between them. The second of these junctions just about manages to be a trumpet. However, things are about to take a turn for the worse as the `fork' signs appear meaning that the dual carriageway is about to end. From here onwards the upgrades are very much piecemeal. The next section, Castle Hill, is due to be improved on-line from 2011/12 and the Draft Orders have been recently published. It's only a mile or so until you get to another roundabout and dual-carriageway bypass: this time for Pembury. There's a grade-separated junction with the A228/A264, then the bypass stops and chucks you back onto old road at Kipping's Cross.

A21 through Hurst Green

Section 3: Pembury - Hastings

This section can be a bit painful when traffic's heavy. After a few miles of winding single carriageway, the village of Lamberhurst has now been bypassed with a dual carriageway that panoramically descends and then climbs to pass under a `land bridge' for the Scotney Castle access road, which means that the access road now crosses the A21 on a bridge with trees, etc., on it, the intention being that you don't notice you're crossing a trunk road; from our viewpoint it's an unexpected tunnel. The road passes Bewl Water on single lane dual carriageway (D2 hatched down) and crosses the border into Sussex at Flimwell. There is a traffic light controlled junction in the middle of Flimwell where the A268 and B2087 are met. Now it is a single-carriageway sixteen and a half mile slog to Hastings.

The A229 is met at an uncontrolled junction just north of Hurst Green and this major trunk road now passes through another village, having another uncontrolled junction, this time with the A265. Continuing south, a roundabout is met on the outside of Robertsbridge, which manages to get a bypass, but only a single-carriageway one. After Robertsbridge there is a roundabout with the A2100 which traipses through Battle. The A21 doesn't head this way as it once did and instead forks east to saunter past nowhere in particular on its way to Hastings.

The other end of the A2100 and the A28 are met at another uncontrolled junction on the northern fringe of Hastings. This is about the point where the Hastings bypass would have met, had it ever been built. Instead the road winds its way into ever denser suburbs having roundabouts with the A2101 and A2102 (meaning it meets three roads in numerical order). How the road meets the A259 on Hastings seafront depends on which map you look at, but whichever way you do go it probably doesn't make a whole lot of difference. One version suggests a TOTSO at St. Margaret's Road to an uncontrolled T on the A259, which is probably most fitting at this point.


A21: 1923 Historic Route

Original route of the A21 through Battle

Old route of the A21 through Knockholt and Badger's Mount

The A21 originally started on the junction Lewisham High Street and Lee High Road. Today, it starts slightly west of here at a roundabout, running on the Lewisham bypass.

The original route at Farnborough was bypassed in the 1930s - the old route becoming the B2158.

At Knockholt, the A21 diverted south of its current line past the station and down London Road. This was originally a straight through route, but by 1927 the A224 Orpington Bypass joined it by Badger's Mount. It then ran down what's now the A224 to Sevenoaks, then what's now the A225 and B245 to Tonbridge.

The route of the old A21 through Tonbridge is now taken by the B245, B2260 where the A21 used to multiplex with the A26 along the High Street, and the A2014.

Pembury, Lamberhurst and Robertsbridge have all been bypassed.

From the A2100 junction it originally followed the A2100, B2159, and A2102. It was realigned to its current route to take over the B2091 and the southern end of the A229 in the 1950s.

Improvement Opening Dates

Year Section Notes
1927 Farnborough Bypass The 1.7 mile road was opened by Mrs Wilfrid Ashley, wife of the Minister of Transport, on 13 April 1927. It was 80 feet wide with a 30 foot carriageway and bituminous surface. Scheme cost was to be £143,000. There was a further 1.2 miles of widening on the Hastings road.
1966 Sevenoaks Bypass Section 1 from Polhill (the northern junction) to the junction at Morant's Court Road was opened on 4 August 1966. The 1967 OS Route Planning map (revised November 1966) shows an extension to A25 Westerham Road.
1967 Sevenoaks Bypass An extension southwards to a temporary junction with Gracious Lane opened on 16 January 1967. It was for northbound traffic only. A section south of here had to be rebuilt on a different alignment owing to landslips because of the slippery clay sub-soil. "The Builder" reported that advice at the planning stage from local farmers was ignored and the piers of the Hubbards Hill Bridge were at 5 to 10 degrees from vertical within a few weeks. The diversion was to cost an extra £1.2 million. To compound matters the new Morants Court bridge was having to be partially rebuilt owing to porous pockets in the concrete caused by a breakdown in the pouring of concrete one night.
1968 Sevenoaks Bypass The southern and final section from Gracious Lane to Riverhill Roundabout opened on 20 March 1968 and the temporary slip road at Gracious Lane closed (see 1967 entry). There was a contra-flow at this location until 27 June 1968 when the southbound carriageway was completed. The bypass was 6.5 miles long, had dual 24 foot carriageways and cost £3.5 million.
1971 Tonbridge Bypass The 6.5 mile dual carriageway was opened on 12 July 1971 by Edward Heath, Prime Minister. Construction had started in September 1968. Contractor was Willetts Motorways Ltd. and cost £5.5 million. It included a viaduct over the River Medway.
1986 Badger's Mount A21 rerouted north of Badger's Mount to meet M25 J4, remaining A21 from Badger's Mount to Morants Court downgraded to the A224.
1988 Pembury Bypass The 2.8 mile dual carriageway from North Farm Roundabout to Kippings Cross Roundabout was opened on 6 May 1988 by Peter Bottomley, Minister for Roads and Traffic. A dual 2 lane road with 7.3m wide carriageways, 1m marginal strips and a 2.5m central reservation. Contractor was M.J. Gleeson Group, tender value £7.5 million.
1989 Robertsbridge Bypass 1 mile single carriageway
2005 Lamberhurst Bypass 1.6 mile D2 dual carriageway, opened March 2005. Contractor was May Gurney.
2017 Tonbridge to Pembury 2.5 mile online and offline dual carriageway was opened on 21 September 2017 by Tonbridge and Malling MP Tom Tugendhat. Contractor was Balfour Beatty, cost £70 million.


  • (Written in 2009) Plans on the Highways Agency website suggest the whole route down to Robertsbridge will be upgraded to grade-separated dual carriageway. What will happen south of here is unclear.
  • (Written in 2019) South Coast Central Plans in 2017 which may have an impact on RIS2 mentioned that on the A21 between the M25 and edge of Hastings performs poorly in safety and in capacity at various locations along its corridor as well as lack of connectivity at M25 J5. No suggests made to what changes could be made, however dualing more parts of the route seems likely and making provisions for local traffic.

Named Junctions

See A21 Named Junctions


Roads UK

Pembury Bypass and Tonbridge to Pembury dualling

Highway England

Related Pictures
View gallery (81)
2015-03-28 13.47.37.jpg2015-03-28 13.47.42.jpg2015-03-28 13.48.57 HDR.jpg2015-03-28 13.49.43.jpg2015-03-28 13.50.54.jpg
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