Kent is rather remarkably well served by major roads leading to and from London. There's the A2 and M2, of course, and the M20. Further east, the A299 extends the major roads to Thanet. And then, in the western corner of the county, there's the A21. But Kent doesn't like sharing its major roads with anyone else - the M20 doesn't go to France, you see, it just stops when it's reached the coast. And so the fast expressway of the A21 rushes through Kent but comes to a halt and reverts to the old single carriageway A21 before the route crosses into East Sussex.

This 15-mile expressway was never conceived as a continuous high-speed route - at least not when its first parts were built. It's actually a series of three bypasses, linked in 2017 with a couple of miles of new road, that flow into each other. Together they bypass and serve three of Kent's major towns - Sevenoaks, Tonbridge and Tunbridge Wells.

The A21 is unusual in having more expressway built than is actually available to drive. In the mid-1960s, construction on the Sevenoaks Bypass was seriously delayed when a section running along a hillside just north of the village of Sevenoaks Weald was found to be unstable. Five major mudslides were discovered, carrying material to an underground lake, thanks to a massive geological fault that had not previously been known about. As a result, the new road was steadily sliding away.

The bypass to the north of that point was opened with a temporary tie-in to an unclassified road called Gracious Lane, which served as the main road until the stricken section could be rebuilt. In the end Hubbards Hill bridge and a section of new road more than a mile in length had to be demolished and rebuilt on a new line 250 metres to the south of the original. Rebuilding a road on this scale is virtually unheard-of in the UK and the problems encountered on the A21 Sevenoaks Bypass are among the worst ever encountered so late in the construction process. Aerial photos to this day still show the line of the original dual carriageway through fields to the north of the modern road.

Since the Sevenoaks Bypass was opened, there have been aspirations to extend the route to reach the coast at Hastings, on and off, for years. But no significant progress has ever been made, for two reasons. One is that the existing road is never quite busy enough or problematic enough to rise to the top of the to-do list. The other is that right now there is nothing much to terminate a high speed expressway on once it reaches the outskirts of Hastings.

The proposed Bexhill and Hastings Bypass, a major trunk road scheme of the 1990s, would have provided somewhere to end an A21 expressway, but that was cancelled a long time ago amid much environmental concern, and has not been seen since. In the meantime, the odd new bypass does appear. The most significant is at Lamberhurst, which looks as though it hopes to one day be part of a London to Hastings expressway, but for now it's just a couple of miles of isolated dual carriageway between two roundabouts.

For now, though - and indeed, for the forseeable future - the A21's motorway-like section reaches from the M25 out to Pembury, 15 miles of exceedingly fast and effective dual carriageway with fine views of the Weald to enjoy on the way. And if you're going to Hastings, enjoy them while you can, because the journey slows down considerably when it ends.

You're not looking at the whole A21

This page is about the parts of the A21 that are designated a motorway or that have motorway characteristics. Other sections of this road will not be featured here and will not count towards the length of the road as shown below.

Start
Sevenoaks
End
Pembury
Passes
Royal Tunbridge Wells
Connects to
Length
15 miles
Open Junctions Section
1966 Sevenoaks Bypass
1971 Tonbridge Bypass
1988 Pembury Bypass
2017 Tonbridge-Pembury

Exit list

Junction   Northbound               Southbound  
M25 J5
26.4 km
Gatwick Airport (M23 Link)
Heathrow Airport (M4 Link)
M25 (W)
Dartford Crossing
(M1 Link, M11 Link)
Bromley (A21)
M25 (N)






M25
(M23)
(M4)
NORTH
M25 (M1, M11, A21)






M26
LanesLanesLanesLanesLanes LanesLanesLanesLanesLanes
0.8 miles, 2 lanes 0.8 miles, 2 lanes
27.6 km Westerham A25
Sevenoaks
Riverhead A25



A25



A25
Sevenoaks
Riverhead A25
Westerham A25
LanesLanesLanesLanes LanesLanesLanesLanes
4 miles, 2 lanes 4 miles, 2 lanes
34.3 km Sevenoaks
A225
A225

B245
Sevenoaks A225
Hildenborough B245
Sevenoaks Weald
LanesLanesLanesLanes LanesLanesLanesLanes
6 miles, 2 lanes 5 miles, 2 lanes
42.5 km A26 A26 Southborough
Tunbridge Wells
A26
LanesLanesLanesLanes
  1 mile, 2 lanes
43.9 km Tonbridge
A26
Industrial Estate
A2014

A26
Tonbridge
A26
Industrial Estate
LanesLanesLanesLanes LanesLanesLanesLanes
2.2 miles, 2 lanes 2.2 miles, 2 lanes
Retail Park
Pembury Hospital
Retail Park
Pembury Hospital
LanesLanesLanesLanes LanesLanesLanesLanes
1 mile, 2 lanes 1 mile, 2 lanes
Tunbridge Wells
A264
Maidstone
A228
A264 A228 Maidstone
A228
Tunbridge Wells
A264
LanesLanesLanesLanes LanesLanesLanesLanes
1.3 miles, 2 lanes 1.3 miles, 2 lanes
Pembury Pembury
LanesLanesLanesLanes LanesLanesLanesLanes
0.6 miles, 2 lanes 0.6 miles, 2 lanes

A21 (A262)
SOUTH
B2160







Paddock Wood
B2160
Hastings
Ashford (A262)
A21
Frant
LanesLanesLanesLanes LanesLanesLanesLanes
Routes

Picture credits