The A3, known as the Portsmouth Road or London Road in sections, is a major road connecting the City of London and Portsmouth passing close to Kingston upon Thames, Guildford, Haslemere and Petersfield. For much of its length, it is classified as a trunk road and therefore managed by National Highways. Almost all of the road has been built to dual carriageway standards or wider. Apart from bypass sections in London, the road travels in a southwest direction and, after Liss, south-southwest.
Close to its southerly end, motorway traffic is routed via the A3(M), then either the east–west A27 or the Portsmouth-only M275 which has multiple lanes leading off the westbound A27 — for non-motorway traffic, the A3 continues into Portsmouth alongside the A3(M), mostly as a single carriageway in each direction through Waterlooville and adjoining small towns. The other section of single carriageways is through the urban environs of Battersea, Clapham and Stockwell towards the northern end, which has to accommodate bus lanes and parking meter bays.
History
Early history
By the 17th century, the historic Portsmouth Road bore great strategic significance as the road link between the capital city and what became the settled main port of the Royal Navy, as well as a non-military port like nearby Chichester — a petition was passed by Her Majesty for the expansion of the bench of justices of the town of Guildford along its route, in consideration of the importance of the Portsmouth Road, in 1603. Many of the other towns and villages that the road passed through gained income and, in the case of towns, a market advantage as a result — principally in the history of Kingston upon Thames, Godalming and Petersfield. The modern A3 follows the general route of the Portsmouth Road, but it bypasses many of the towns and villages along the way, leaving the various stretches of the old route for local traffic — for instance, the A307, its original course through Kingston-upon-Thames and Esher, retains its name, Portsmouth Road.
The road was once the haunt of highwaymen such as Jerry Abershawe, who in the 18th Century terrorised the area around Kingston and led a gang based at the Bald Faced Stag Inn on the Portsmouth Road. Another particularly dangerous location was in the vicinity of the wooded crest skirting the Devil's Punch Bowl, Hindhead, about south-west of Guildford.
Later History
A programme of road improvements, starting in the 1920s, transformed the road, so that it is now predominantly a two or three lane carriageway, bypassing the town centres; south of the South Downs National Park, it includes a section of motorway, the A3(M), just before the road reaches the A27 at Havant. The construction of the Kingston and Guildford bypasses in the 1920s and 1930s made use of temporary narrow gauge railways to move the construction materials. The Esher bypass, between Hook from the first mentioned bypass to the M25, is three lanes with a motorway-standard hard shoulder; from there to Guildford the road has three lanes.
Lord Montagu of Beaulieu stressed the urgency of building a Kingston bypass in 1911, but public funds were not secured before the onset of World War I and were not available in the aftermath. By the early 1920s, traffic in Kingston town centre had increased by over 160% in 10 years in the coaching town and the decision was taken in 1923 to revive the plans, with the contract worth £503,000 (). Work started in 1924, and it was opened by the Prime Minister, the Rt Hon Stanley Baldwin MP, on 28 October 1927. It ran for from the Robin Hood Gate of Richmond Park to the outskirts of Esher. The opening ceremony concluded with refreshments for 800 guests in marquees near to the northern start/end. Its construction immediately attracted developments of housing where access was easiest. The Restriction of Ribbon Development Act 1935 came too late to prevent this private housing, which is apparent where the A3 winds through Tolworth and New Malden, where the architecture includes concrete to art nouveau apartments, Mock-Tudor gabled houses and gabled Arts and Crafts movement-inspired houses. The final section of the Kingston By-Pass now forms part of the A309 thanks to the construction of the Esher By-Pass.
The complexity of the double roundabout at the junction between the A309 Kingston by-pass and the A307 led to it being referred to colloquially as the Silly Isles, later the junction officially adopted the name The Scilly Isles.