A24

The A24 forms a north-south radial route from London to Worthing. It serves many south London suburbs, along with Leatherhead, Dorking, Horsham and Worthing.

Route

Section 1: Clapham Common – Leatherhead

The A24 starts at Clapham Common, forming the "south" side, and making a triangle with the A3 (north side) and the A205 South Circular Road. It continues the line of the A3 from London Bridge, following the Roman Stane Street and the Northern Line of the London Underground, the straight route being highly convenient for railway construction. Interestingly, the typical domed station roofs of the Northern Line give way at this point to the more recent art-deco style, as the underground line south of Clapham was built some 30 years after the original stretch.

The A24 treads its dreary way through Balham (A214 - possibly part of Abercrombie's intended Ringway 2) and Tooting (A217, of which more later) to Colliers Wood. Here the original route turned right into Merton High Street (now the A238) to South Wimbledon Tube Station,where it turned left onto Morden Road (now the A219). The present route bears left at Colliers Wood (the former A236), and then turns right to leave the A236 and follow a former railway line (Merantun Way), crossing the River Wandle to rejoin its original route just south of South Wimbledon. The former railway line was only single track, and to squeeze a new road into the space certain economies had to be made - such as no pavements and thus a ban on pedestrians.

On rejoining Morden Road the A24 then crosses the Wimbledon to Croydon tram line (another former railway) at Morden Road tramstop, and continues to Morden Hall and Morden Tube station, the end of the Northern Line. Here the A297 branches off for St Helier and the A217, which gains in significance as it leaves London. Here also the A24 rejoins the Roman Road, which took a different line across the Wandle.

The A24, now known as London Road, heads for Ewell, which is now bypassed in a multiplex with the A240 Kingston to Banstead (for A217) road. Coming north, the A24 turns off the A240, but going south the A240 turns off the A24, and the A24 then continues into the centre of Epsom and Ashtead. It is primarily because of the lack of bypasses for these towns that A24 traffic from central London is directed to use the A3 to Hook and then the A243 to Leatherhead.

The A24 meets the A243 and A245 on the outskirts of Leatherhead, near junction 9 of the westbound M25 (the eastbound junction is further back towards Oxshott), at the junction of the A243 and A244. The A24 itself crosses the M25 with no junction and meets the A243 and B2122 on the outskirts of Leatherhead. Following the A243 here would bring you first to junction 9 of the westbound M25, and then to the eastbound junction where it also meets the A244.

At this point the original route went into Leatherhead. This, and the original A246 out the other side, became the A2012 when the A24 bypass was built, and since the coming of the M25 has been downgraded to the B2122. The bypass runs first south and then steeply downhill west to meet the original route along the River Mole south of Leatherhead, (later an extension of the A244 and now the B2450).

Section 2: Leatherhead – Horsham

A24, Mickleham Bends

The Mole Gap is a strong candidate for the most scenic road in the Home Counties, as it twists through the narrow valley through the North Downs. On the Mickleham bends [as this road is referred to] until the early 2000s, it was 2 lanes southbound, but the very poor accident record led Surrey County Council to hatch over one lane and impose a 50mph limit. There were elaborate plans for tunnels and new alignments, but inevitably these never got off the drawing board.

The Mole is in fact the only river between the Wey (at Guildford) and the Darent (at Sevenoaks) to breach the Downs, so the gap has been a major communications route for thousands of years. Unsurprisingly, the road has to share the valley not only with the river, but also with a railway line.

The original road through Mickleham (now B2209) is bypassed by a newer, mostly dual-carriageway route closer to the river, which ends at Burford Bridge, the roundabout for the famed National Trust site at Boxhill. This area is also very popular with bikers.

Crossing the Mole, the A24 now runs into Dorking. A western bypass of Dorking is numbered the A2003, but the A24 avoids the town centre to the east along Deepdene Avenue, a mainly single-carriageway inter-wars bypass, crossing the A25 at a roundabout. This rejoins the original route at the roundabout at North Holmwood. Here the A24 becomes dual carriageway for the run through the high ground around Leith Hill, the highest point in Surrey.

At Beare Green the A29 turns off, to rejoin the Roman Stane Street on its way to Bognor Regis. The A24, on the other hand, continues on a short single carriageway stretch through Kingsfold (where a former spur of the A29, now declassified, turns off), to Warnham, where the A264 joins it for a multiplex bypass of Horsham.

Section 3: Horsham – Worthing

The A24 continues as the dual carriageway Horsham bypass. The A264 leaves at the large motorway-style Farthings Hill interchange. The original A24, now the B2180 (north of the town centre) and B2237 (south), rejoins near Christ's Hospital School. The road then continues, first bypassing Southwater, then south of there the carriageways part ways slightly, with the southbound carriageway being the original single carriageway alignment. Due to the poor alignment southbound there is a 50mph speed limit in force. Northbound the road is straighter and remains NSL.

We then reach a set of traffic lights for a junction with the A272. South of here the road is still D2 but has a number of at-grade junctions, notably with the B2135 and a minor road for Dial Post and Ashurst, both of which have 60mph limits with speed camaras. Part of this section serves as a bypass for Dial Post, and there are plans to close the gaps and build three GSJs.

Ashington is then bypassed, with two GSJs for access to Ashington village and the B2133 to Billingshurst. The A24 then meets A283 at a roundabout with this section forming a bypass of Washington. The northbound and eastbound approaches to this roundabout can get very jammed at peak-times, though there are no plans to improve it. Before the bypass was built there was a short multiplex with the A283 here.

The South Downs ridge has many more gaps through it than does the North, but this time the A24 climbs over the top, to a junction with the A280 at Findon, on the Findon bypass. Due to the poor alignment once again the speed limit is reduced first to 60mph then 50mph. The Findon bypass continues as a narrow D2 mostly painted down to one lane (D1) with the speed limit reducing to 40mph before entering Findon Valley as a single carriageway on the outskirts of Worthing. We then reach Offington Corner, where the A2031 carries straight on for West Worthing; the A24 turns left onto a half mile multiplex with the A27, losing it again at the Grove Lodge roundabout. Almost immediately south of the roundabout the A2032 starts with a right-turn through the reservation. The A24 is briefly dual carriageway past Broadwater Green, then single again through Broadwater itself. It meets the B2223 at a set of traffic lights and, now a dual carriageway once more, grabs its bucket and spade and heads for the sea. Past the railway station it meets first a minor road then the other end of the A2031 at roundabouts. Were it not for the A259, which bars its way (at another roundabout) as it does so many other roads to the south coast, the A24 would carry straight on until it reached the end of the pier. From the southern most point of the A24 heading north it is possible to go through all speed limits in order without breaking the sequence.

History

Clapham Common – Leatherhead

A24 historic route from 1922/3 numbering

The A24 is mainly on its original route, save for short bypasses at Morden and Ewell.

Leatherhead – Horsham

It originally ran through Leatherhead. Initial plans for Ringway 4 get suspiciously close to the top end of the D2 section at Leatherhead. Mickleham has been bypassed, with the old road being the B2209. In Dorking, the A24 diverged from its present route north of the roundabout with the A25, then ran up London Road to multiplex with the A25 along the High Street. It then followed what is now the second half of the A2003 to reach the original route at the roundabout at North Holmwood. The Deepdene Avenue bypass which forms the current route to the east of the town centre gives the impression of having been built in the inter-war period.

North Holmwood is now bypassed, it then uses the original route through Mid Holmwood and part of South Holmwood, before using a new alignment around the Southern-most part of Holmwood near the station. Beare Green and Capel are also bypassed. Then as original to Great Daux roundabout (A264)

Horsham – Worthing

The Horsham bypass was built in several sections, with the B2237 through Horsham being the old road which was bypassed first. The short section from the northern end of the B2237 to the A264 was built later, with the old road running parallel as unclassified. The GSJ at Farthings Hill was originally built flat with provision for the underpass when the A264 Broadbridge Heath bypass was built. Southwater is bypassed with the old road initially being the A2400, now declassified. From here the southbound carriageway was the original road.

The A24 originally ran through the villages of Dial Post, Ashington and Washington, the Ashington bypass being the latest addition. It ran through Findon, bypassed in the 1930s. South of Findon to the A27, the A24 is a single carriageway, now has a shared cycle/footway linking the village to the town centre, this route was completed in 2023. The route in Worthing has obviously been dualled at some point, and before the dualling of the A259 around the town centre would have run at least to the traffic lights on the A259 at Richmond Road, if not all the way to Marine Parade and the pier.

Opening Dates

Year	Section	Notes
1932	Ewell Bypass	Daily Mirror of 30 July 1932 reported that all roundabouts would be in operation on the road tomorrow. The £43,000 scheme was sanctioned in July 1930 and County Council direct labour construction authorised in August 1930.
1933	Leatherhead Bypass	Part of section 2 from A24 Epsom Road to unclassified Headley Road opened 31 July 1933.
1934	Dorking Bypass	The 1.9 mile road from London Road to Flint Hill was fully opened on 2 June 1934. Part had opened in March 1934. A section of Chart Lane was incorporated. Over 2,000 rhododendrons were planted as a beautifying scheme. Estimated cost was £102,246.
1934	Leatherhead Bypass	The remainder of section 2 from unclassified Headley Road to A24 Dorking Road opened in June 1934 (see 1933 entry also). Estimated cost of section 2 was £131,150.
1938	Findon Bypass	One carriageway was opened for use on 25 January 1938. The second carriageway was opened for Easter (15 to 18 April 1938).
1938	Mickleham Bypass	The 2.4 mile dual carriageway was to be fully opened on 4 June 1938 (per the Daily Express of 1 June 1938), A photograph appeared in the 6 June 1938 edition. It included the section northwards from Mickleham Corner to Leatherhead Bypass at Givons Grove which had opened by 4 March 1938. The carriageways were 22 feet wide and 20 feet apart, cyclepaths were 9 feet wide. The new bridge over the River Mole at Burford had an 80 foot span and was 100 foot wide. Scheme cost was £125,500.
1960	Worthing: Broadwater Green Dualling	The dualling between South Farm Road and Ardshiel Road was opening on 3 June 1960. The street lights which were on the edge of the Green were now in the centre of the road.
1960 - 1963	The Bar Diversion	A new 0.8 mile northbound carriageway to the south of Southwater to create a split dual carriageway. Shown on 1963 OS One inch map. Not on 1960 edition.
1964	Horsham Western Bypass	The 3 mile dual carriageway from Robin Hood Roundabout to Hop Oast Roundabout was due to open on 20 November 1964 without ceremony (per a “30 year’s ago” feature in the West Sussex County Times of 18 November 1994).
1968	North Holmwood Bypass	A temporary diversion notice from 16 April 1968 (for six weeks) used the new dual carriageway. The notice was for works at the north end of Spook Hill. Surrey Advertiser reported on 2 July 1966 that work had started for the 18 months contract. It may have opened in late 1967. The scheme included the 0.5 mile bypass and one mile dualling southwards to Folly Lane, South Holmwood. Estimated cost was £545,000.
1968	Washington Bypass	The main section of the 2 mile dual carriageway was opened on 16 August 1968 without ceremony. The complete stretch from 80 yards north of Rock Crossroads to the existing dual carriageway 0.5 mile north of North Farm was not expected to open until the end of the year. 24 foot carriageways. Contractor was Tarmac Ltd.
1982	Capel Bypass	Reported by the West Sussex County Times of Friday 14 May 1982 that it had opened “on Friday”. 2.5 miles. Contractor was Bovis Construction Company, cost £2.6 million.
1982	Southwater Bypass	Pollards Way. The dual carriageway from Hop Oast Roundabout at the southern end of Horsham Bypass to Pollards Hill Roundabout was opened on 1 December 1982 by schoolboy Andrew Knifton, overseen by Christopher Buckle, West Sussex County Council Chairman. It was stated to be over 2.5 miles long which would indicate some further online improvement at one of the bypass ends. Contractor was Mears, cost £4.1 million.
1988	Dial Post Bypass	The 1.1 mile road was opened on 7 September 1988 by Peter Shepherd, Chairman of West Sussex County Council. Contractor was Edmund Nuttall Ltd., contract price £1.9 million.
1988	Horsham Northern Bypass	Dualling between Robin Hood Roundabout and Great Daux Roundabout as part of the A264 Northern Bypass scheme which was opened on 5 December 1988 by Peter Shepherd, West Sussex County Council Chairman.
1989	Merton High Street Relief Road	Merantun Way. Opened in February 1989 per a Wandle Industrial Museum annotated photograph. It was described as new in a 3 August 1989 advert in the Leatherhead Advertiser. Built on the course of the former railway line from Merton to Tooting.
1994	Ashington Bypass	The dual carriageway was officially opened on 21 December 1994 per the West Sussex County Times of 10 March 1995 and the Land Compensation Act notice. However, the newspaper mentioned that traffic had used the road in November 1994. Cost £6 million.

Future

Horsham – Capel

In 2003 a new Single carriageway alignment was approved by the local council between the Great Daux Roundabout on the northern side of Horsham to the Clarkes Green Roundabout south of Capel. This new piece of road is the piece of the A24 between Findon and Dorking that isn't currently a dual carriageway, and hasn't had its alignment changed. In 2010 the central government didn't identify it for delivery or improvements.

The scheme was due to cost £57 million in 2006. The scheme was originally planned to be D2, later revised to just a S3 (alternative S2+1) as an S2 wouldn't be able to handle the demand.

There are large plans for thousands of new homes around Horsham, it is expected that these upgrades will happen as a result of the new homes.

Ashington – Southwater

There were plans for closing of 28 gaps, installation of crash barriers in the central reservation, 3km of hard shoulder and the building of three GSJ, at the Buckbarn Crossroads, Partridge Green Turn and Dial Post South. These plans were dismissed in 2011 due to not being value for money despite 70 accidents over 4 years at these gaps/junctions, of which 2 were fatal. In the early 2020s, it has since been proposed that some of the junctions that would have been grade separated, would become signalised at-grade junctions, and buck barn becoming a through about junction, as well as some roundabouts on the corridor becoming signalised.

Links

• Roads.org.uk: Mickleham Bends Photo Gallery
• CBRD: Video footage of the Mickleham Bends (archive.org)
• Proposed A24 grade separation and other improvement from 2003