The A1, also known as the Great North Road, is the longest numbered road in the United Kingdom, at . It connects London, the capital of England, with Edinburgh, the capital of Scotland. The numbering system for A-roads, devised in the early 1920s, was based around patterns of roads radiating from two hubs at London and Edinburgh. The first number in the system, A1, was given to the most important part of that system: the road from London to Edinburgh, joining the two central points of the system and linking two of the UK's mainland capital cities. It passes through or near north London, Hatfield, Stevenage, Baldock, Biggleswade, Peterborough, Stamford, Grantham, Newark-on-Trent, Retford, Doncaster, Pontefract, Leeds, York, Wetherby, Ripon, Darlington, Durham, Gateshead, Newcastle upon Tyne, Morpeth, Alnwick, Berwick-upon-Tweed, Dunbar, Haddington, Musselburgh, and east Edinburgh.

It was designated by the Ministry of Transport in 1921, and for much of its route it followed various branches of the historic Great North Road, the main deviation being between Boroughbridge and Darlington. The course of the A1 has changed where towns or villages have been bypassed, and where new alignments have taken a slightly different route. Between the North Circular Road in London and Morpeth in Northumberland, the road is a dual carriageway, several sections of which have been upgraded to motorway standard and designated A1(M). Between the M25 (near London) and the A720 (near Edinburgh) the road is part of the unsigned Euroroute E15 from Inverness to Algeciras.

History

The A1 is the latest in a series of routes north from London to York and beyond. It was designated in 1921 by the Ministry of Transport under the Great Britain road numbering scheme. The earliest documented northern routes are the roads created by the Romans during the period from AD 43 to AD 410, which consisted of several itinera (plural of iter) recorded in the Antonine Itinerary. A combination of these were used by the Anglo-Saxons as the route from London to York, and together became known as Ermine Street. Ermine Street later became known as the Old North Road. Part of this route in London is followed by the current A10. By the 12th century, because of flooding and damage by traffic, an alternative route out of London was found through Muswell Hill, and became part of the Great North Road. A turnpike road, New North Road and Canonbury Road (A1200 road), was constructed in 1812 linking the start of the Old North Road around Shoreditch with the Great North Road at Highbury Corner. While the route of the A1 outside London mainly follows the Great North Road route used by mail coaches between London and Edinburgh, within London the coaching route is only followed through Islington.Norman W. Webster (1974) The Great North Road

The Ferryhill Cut was opened in 1923. A number of bypasses were built from 1926 onwards, including around Barnet and Hatfield in 1927, but it was not until that they were renumbered A1. The Chester-le-Street bypass, opened in 1931, was the first bypass to be built as a dual carriageway. In 1960 Stamford, Biggleswade and Doncaster were bypassed, as was Retford in 1961. Baldock, Eaton Socon and Buckden were bypassed in 1967. During the early 1970s plans to widen the A1 along Archway Road in London were abandoned after considerable opposition and four public inquiries during which road protesters disrupted proceedings. The scheme was finally dropped in 1990. The Hatfield cut-and-cover was opened in 1986.

A proposal to upgrade the whole of the A1 to motorway status was investigated by the government in 1989 but was dropped in 1995, along with many other schemes, in response to road protests against other road schemes (including the Newbury Bypass and the M3 extension through Twyford Down).

Inns

The inns on the road, many of which still survive, were staging posts on the coach routes, providing accommodation, stabling for the horses and replacement mounts. Few of the surviving coaching inns can be seen while driving on the A1, because the modern route now bypasses the towns with the inns.

Route

The A1 runs from outside St Paul's tube station in the City of London near St. Paul's Cathedral to Edinburgh Waverley railway station in the centre of the Scottish capital. It shares its London terminus with the A40 and A1211 roads at the Museum of London Rotunda. It runs out of London via St. Martin's Le Grand and Aldersgate Street, through Islington (where Goswell Road and Upper Street form part of its route), up Holloway Road, through Highgate, Mill Hill, and Barnet where it has its last at-grade roundabout for 37 miles at Stirling Corner.

The road enters Hertfordshire just before Potters Bar, near the junction with the M25 at the South Mimms Services. The route here becomes the A1(M) and subsequently passes underneath Hatfield, and by Welwyn, Stevenage, and Baldock. But it once again becomes a dual carriageway with some at-grade junctions from Baldock Junction 10, past Biggleswade, Sandy and several small villages including the ‘Black Cat’ roundabout to Buckden, then on to Alconbury and the A1(M) at Junction 14. Junctions 11, 12 and 13 (for a motorway-standard road) may not be built until upgrading of the A1 here to a motorway is approved (possibly when the planned New Town at Tempsford is commenced).

Continuing north, the A1 runs on modern bypasses around Stamford, Grantham, Newark-on-Trent, Retford, Bawtry, Doncaster, Knottingley, Garforth, Wetherby, Knaresborough, Boroughbridge, Scotch Corner, Darlington, Newton Aycliffe, Durham and Chester-le-Street, past the Angel of the North sculpture and the Metrocentre in Gateshead, through the western suburbs of Newcastle upon Tyne, Morpeth, Alnwick, Berwick-upon-Tweed, into Scotland at Marshall Meadows, past Haddington and Musselburgh before arriving in Edinburgh at the East End of Princes Street near Waverley Station, at the junction of the A7, A8 and A900 roads.

Scotch Corner, in North Yorkshire, marks the point where, before the M6 was built, the traffic for Glasgow and the west of Scotland diverged from that for Edinburgh. As well as a hotel there have been a variety of sites for the transport café, now subsumed as a motorway services.

There are five roundabouts north of the Stirling corner junction in Barnet: Biggleswade south, Biggleswade north, Sandy A603, the ‘Black Cat’ A428/A4211, and lastly Buckden, after which there are no more roundabouts for until the Berwick A1167. The Black Cat roundabout is being redeveloped and is due to fully re-open in 2027.

Overview and post-First World War developments

A section of the road in North Yorkshire, from Walshford to Dishforth, was upgraded to motorway standard in 1995. Neolithic remains and a Roman fort were discovered.

A section of the road from Alconbury to Peterborough was upgraded to motorway standard at a cost of £128 million (£ as of ), which opened in 1998 requiring moving the memorial to Napoleonic prisoners buried at Norman Cross.

A number of sections between Newcastle and Edinburgh were dualled between 1999 and 2004, including a section from Spott Wood to Oswald Dean in 1999, sections from Bowerhouse to Spott Road and from Howburn to Houndwood in 2002–2003 and the "A1 Expressway", from Haddington and Dunbar in 2004. The total cost of these works was £50 million.

Plans to dual the single carriageway section of road north of Newcastle upon Tyne were shelved in 2006 as they were not considered a regional priority by central government. The intention was to dual the road between Morpeth and Felton and between Adderstone and Belford.

In 1999, a section of A1(M) between Bramham and Hook Moor opened to traffic along with the extension of the M1 from Leeds. Under a DBFO contract, sections from Wetherby to Walshford and Darrington to Hook Moor were opened in 2005 and 2006.

Recent developments A1 Peterborough to Blyth grade separated junctions Between September 2006 and October 2009, six roundabouts on the A1 and the A1(M) to Alconbury were replaced with grade-separated junctions. These provide a fully grade-separated route between the Buckden roundabout (just north of St Neots and approximately north of the Black Cat roundabout) and just north of Morpeth. This project cost £96 million.

Section Fully operational date Blyth (A614) May 2008 Apleyhead (A614/A57) May 2008 Markham Moor (A57) March 2009 Gonerby Moor (B1174) June 2008 Colsterworth (A151) and the junction with the B6403 October 2009 Carpenters Lodge (Stamford) (B1081) November 2008

A1(M) Bramham to Wetherby motorway Upgrading the of road to dual three-lane motorway standard between the Bramham/A64 junction to north of Wetherby to meet the section of motorway at a cost of £70 million began in 2006, including a road alongside for non-motorway traffic. The scheme's public inquiry began on 18 October 2006 and the project was designed by James Poyner. Work began in May 2007, the motorway section opened in July 2009 and remaining work on side roads was still ongoing in late August and was expected to be completed by the end of 2009.

A1(M) Dishforth to Leeming motorway Upgrading of the existing dual carriageway to dual three-lane motorway standard, with a local road alongside for non-motorway traffic, between Dishforth (A1(M)/A168 junction) and Leeming Bar, began in March 2009 and opened to traffic on or about the scheduled date of 31 March 2012.

A1(M) Leeming to Barton motorway It had originally been proposed that the road would be upgraded to motorway from Dishforth to Barton (between Scotch Corner and Darlington), which was the start of current northernmost section of A1(M). In 2010 the section between Leeming and Barton was cancelled as part of government spending cuts but it was reinstated in December 2012. Work began on 3 April 2014 and was expected to be completed by Spring 2017, but only reached completion in March 2018 due in part to significant Roman-era archaeological finds along the route of the motorway. Completion has provided a continuous motorway-standard road between Darrington (south of M62 junction) and Washington, and given the North East and North Yorkshire full motorway access to London (via the M1 at Darrington and Hook Moor).

Councils in the north east have called for the section from Hook Moor in Yorkshire (where the M1 link road joins the A1(M)) to Washington to be renumbered as the M1. They maintain that this would raise the profile of the north-east and be good for business.

A1 (Gateshead Western Bypass) In his Autumn Statement on 5 December 2012, the Chancellor of the Exchequer announced that the Government would upgrade a section of road from two to three lanes in each direction within the highway boundary at Lobley Hill (between Coal House and the Metro Centre), Gateshead at a cost of £64 million and create parallel link roads between the Lobley Hill and Gateshead Quay junctions. The same Road investment strategy announcement said that the remaining section of road between Birtley and Coal House will also be widened to three lanes each way, alongside the replacement of the Allerdene Bridge. A modified scheme commenced in August 2014 and was open to traffic in June 2016. The road is now three lanes each way with lane 3 narrower than lanes 1 and 2 so that all existing bridges remained as originally built.

The A1 around Durham, Gateshead and Newcastle has seen a number of incarnations, following routes through, to the east and to the west of both Gateshead and Newcastle. See A1 (Newcastle upon Tyne) for more information.

Ellington to Fen Ditton scheme