numbering scheme
There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator. The schemes can be considered to be examples of a primary key of a database management ...
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
.
Each road is given a single letter (which represents the road's category) and a subsequent number (between 1 and 4 digits). Introduced to arrange funding allocations, the numbers soon became used on maps and as a method of navigation. Two sub-schemes exist: one for
motorways
A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway and expressway. Other similar terms i ...
, and another for non-motorway roads. While some major roads form part of the
International E-road network
The international E-road network is a numbering system for roads in Europe developed by the United Nations Economic Commission for Europe (UNECE). The network is numbered from E1 up and its roads cross national borders. It also reaches Centr ...
, no E-routes are signposted in Great Britain, or the rest of the UK. Due to changes in local road designation, in some cases roads are numbered out of zone. There are also instances where road numbers in one area are also found in another location. For example the A594 is designated as the Leicester Ring Road and also allocated to a road in Cumbria.
The scheme applies only to England, Scotland and Wales; a similar system is used in
Northern Ireland
Northern Ireland ( ga, Tuaisceart Éireann ; sco, label= Ulster-Scots, Norlin Airlann) is a part of the United Kingdom, situated in the north-east of the island of Ireland, that is variously described as a country, province or region. Nort ...
Isle of Man
)
, anthem = "O Land of Our Birth"
, image = Isle of Man by Sentinel-2.jpg
, image_map = Europe-Isle_of_Man.svg
, mapsize =
, map_alt = Location of the Isle of Man in Europe
, map_caption = Location of the Isle of Man (green)
in Europe ...
,
Jersey
Jersey ( , ; nrf, Jèrri, label=Jèrriais ), officially the Bailiwick of Jersey (french: Bailliage de Jersey, links=no; Jèrriais: ), is an island country and self-governing Crown Dependencies, Crown Dependency near the coast of north-west F ...
and
British overseas territories
The British Overseas Territories (BOTs), also known as the United Kingdom Overseas Territories (UKOTs), are fourteen dependent territory, territories with a constitutional and historical link with the United Kingdom. They are the last remna ...
. These other numbering schemes use similar conventions.
History
Work on classification began in 1913. The Road Board had been established in 1909 to administer
Vehicle Excise Duty Vehicle Excise Duty (VED; also known as "vehicle tax", "car tax", and more controversially as "road tax", and formerly as a "tax disc") is an annual tax that is levied as an excise duty and which must be paid for most types of powered vehicles which ...
- money raised by taxation to pay for new road construction and for repair of damage done to existing roads by the growing number of motorists. p.30. As the Board needed to work out which roads should be funded, upgraded or replaced, its secretary, William Rees Jeffreys, appointed
Henry Maybury
Brigadier-General Sir Henry Percy Maybury (17 November 1864 – 7 January 1943) was a British civil engineer. He began his career as a railway engineer, working on many railways in England and Wales before becoming the county surveyor for ...
, one of the Board's senior engineers, to devise a classification system and then assign numbers to the highways for identification purposes. The work was interrupted by the
First World War
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
. It did not resume until the
Ministry of Transport
A ministry of transport or transportation is a ministry responsible for transportation within a country. It usually is administered by the ''minister for transport''. The term is also sometimes applied to the departments or other government age ...
was formed in 1919 and given authority to classify highways and to allocate funding for road maintenance, authority for which was granted by section 17 (2) of the
Ministry of Transport Act 1919
The Department for Transport (DfT) is a department of His Majesty's Government responsible for the English transport network and a limited number of transport matters in Scotland, Wales and Northern Ireland that have not been devolved. The de ...
. A classification system was created in 1922, under which important routes connecting large population centres, or for through traffic, were designated as Class I, and roads of lesser importance were designated as Class II. The definitive list of those roads was published on 1 April 1923, following consultations with
local authorities
Local government is a generic term for the lowest tiers of public administration within a particular sovereign state. This particular usage of the word government refers specifically to a level of administration that is both geographically-loca ...
. Government funding towards the repairs of these roads were set at 60% for the former and 50% for the latter.
Shortly after this, the numbers started to appear in road atlases and on signs on the roads themselves, making them a tool for motorists in addition to their use for determining funding. The numbers of the roads changed quite frequently during the early years of the system, because it was a period of rapid expansion of the network and some numbered routes did not follow the most usual routes taken. The Trunk Roads Act 1936 gave the Ministry direct control of major routes and a new classification system was created to identify these routes. Originally, those numbers beginning in T were to be made public, but that was eventually deemed unnecessary.
With the introduction of motorways in the late 1950s, a new classification of "M" was introduced. In many cases the motorways duplicated existing stretches of A road, which therefore lost much of their significance and were in some cases renumbered. There was no consistent approach to the renumbering – some A roads retained their existing number as non-primary roads (e.g. the A40 running alongside the M40), others were given "less significant" numbers (e.g. the A34 in Warwickshire became the A3400 after the M40 was built), and the remainder were downgraded to B or unclassified roads (e.g. the A38, which was replaced by the M5 between Tiverton and
Exeter
Exeter () is a city in Devon, South West England. It is situated on the River Exe, approximately northeast of Plymouth and southwest of Bristol.
In Roman Britain, Exeter was established as the base of Legio II Augusta under the personal comm ...
). Occasionally, the new motorway would take the name of the old A road rather than having its own number. The most notable example of that is the
A1(M)
A1(M) is the designation given to a series of four separate motorway sections in England. Each section is an upgrade to a section of the A1, a major north–south road which connects London, the capital of England, with Edinburgh, the capit ...
.
Zoning system
Non-motorway
In England and Wales the road numbering system for all-purpose (i.e. non-motorway) roads is based on a radial pattern centred on
London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...
. In Scotland the same scheme is centred on
Edinburgh
Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...
. In both cases the main single-digit roads normally define the zone boundaries. The exception is between Zones 1 and 2, where the
River Thames
The River Thames ( ), known alternatively in parts as the The Isis, River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the Longest rivers of the United Kingdom, se ...
defines the boundary so that all of Kent is in
Zone 2.
* Zone 1: North of the
Thames
The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...
, east of the A1 covering
Greater London
Greater may refer to:
*Greatness, the state of being great
*Greater than, in inequality (mathematics), inequality
*Greater (film), ''Greater'' (film), a 2016 American film
*Greater (flamingo), the oldest flamingo on record
*Greater (song), "Greate ...
,
Essex
Essex () is a county in the East of England. One of the home counties, it borders Suffolk and Cambridgeshire to the north, the North Sea to the east, Hertfordshire to the west, Kent across the estuary of the River Thames to the south, and G ...
,
Cambridgeshire
Cambridgeshire (abbreviated Cambs.) is a Counties of England, county in the East of England, bordering Lincolnshire to the north, Norfolk to the north-east, Suffolk to the east, Essex and Hertfordshire to the south, and Bedfordshire and North ...
,
East Anglia
East Anglia is an area in the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire. The name derives from the Anglo-Saxon kingdom of the East Angles, a people whose name originated in Anglia, in ...
,
Lincolnshire
Lincolnshire (abbreviated Lincs.) is a county in the East Midlands of England, with a long coastline on the North Sea to the east. It borders Norfolk to the south-east, Cambridgeshire to the south, Rutland to the south-west, Leicestershire ...
, parts of
Yorkshire
Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...
,
County Durham
County Durham ( ), officially simply Durham,UK General Acts 1997 c. 23Lieutenancies Act 1997 Schedule 1(3). From legislation.gov.uk, retrieved 6 April 2022. is a ceremonial county in North East England.North East Assembly â€About North East E ...
,
Tyne and Wear
Tyne and Wear () is a metropolitan county in North East England, situated around the mouths of the rivers Tyne and Wear. It was created in 1974, by the Local Government Act 1972, along with five metropolitan boroughs of Gateshead, Newcastl ...
,
Northumberland
Northumberland () is a county in Northern England, one of two counties in England which border with Scotland. Notable landmarks in the county include Alnwick Castle, Bamburgh Castle, Hadrian's Wall and Hexham Abbey.
It is bordered by land on ...
, parts of the
Scottish Borders
The Scottish Borders ( sco, the Mairches, 'the Marches'; gd, Crìochan na h-Alba) is one of 32 council areas of Scotland. It borders the City of Edinburgh, Dumfries and Galloway, East Lothian, Midlothian, South Lanarkshire, West Lothi ...
,
East Lothian
East Lothian (; sco, East Lowden; gd, Lodainn an Ear) is one of the 32 council areas of Scotland, as well as a historic county, registration county and lieutenancy area. The county was called Haddingtonshire until 1921.
In 1975, the histo ...
and on up to
Edinburgh
Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...
* Zone 2: South of the
Thames
The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...
, east of the A3 covering part of
Surrey
Surrey () is a ceremonial and non-metropolitan county in South East England, bordering Greater London to the south west. Surrey has a large rural area, and several significant urban areas which form part of the Greater London Built-up Area. ...
,
Sussex
Sussex (), from the Old English (), is a historic county in South East England that was formerly an independent medieval Anglo-Saxon kingdom. It is bounded to the west by Hampshire, north by Surrey, northeast by Kent, south by the English ...
and
Kent
Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces ...
* Zone 3: North/West of the A3, south of the A4 covering part of Surrey,
Hampshire
Hampshire (, ; abbreviated to Hants) is a ceremonial county, ceremonial and non-metropolitan county, non-metropolitan counties of England, county in western South East England on the coast of the English Channel. Home to two major English citi ...
(excluding
Portsmouth
Portsmouth ( ) is a port and city in the ceremonial county of Hampshire in southern England. The city of Portsmouth has been a unitary authority since 1 April 1997 and is administered by Portsmouth City Council.
Portsmouth is the most dens ...
), the
Isle of Wight
The Isle of Wight ( ) is a county in the English Channel, off the coast of Hampshire, from which it is separated by the Solent. It is the largest and second-most populous island of England. Referred to as 'The Island' by residents, the Isle of ...
and
South West England
South West England, or the South West of England, is one of nine official regions of England. It consists of the counties of Bristol, Cornwall (including the Isles of Scilly), Dorset, Devon, Gloucestershire, Somerset and Wiltshire. Cities and ...
* Zone 4: North of the A4, south/west of the A5 covering the
south
South is one of the cardinal directions or Points of the compass, compass points. The direction is the opposite of north and is perpendicular to both east and west.
Etymology
The word ''south'' comes from Old English ''sūþ'', from earlier Pro ...
and
West Midlands
West or Occident is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sun sets on the Earth.
Etymology
The word "west" is a Germanic word passed into some ...
,
Oxfordshire
Oxfordshire is a ceremonial and non-metropolitan county in the north west of South East England. It is a mainly rural county, with its largest settlement being the city of Oxford. The county is a centre of research and development, primarily ...
,
Bristol
Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...
,
Gloucestershire
Gloucestershire ( abbreviated Glos) is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn and the entire Forest of Dean.
The county town is the city of Gl ...
,
Buckinghamshire
Buckinghamshire (), abbreviated Bucks, is a ceremonial county in South East England that borders Greater London to the south-east, Berkshire to the south, Oxfordshire to the west, Northamptonshire to the north, Bedfordshire to the north-ea ...
and
south
South is one of the cardinal directions or Points of the compass, compass points. The direction is the opposite of north and is perpendicular to both east and west.
Etymology
The word ''south'' comes from Old English ''sūþ'', from earlier Pro ...
,
west
West or Occident is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sunset, Sun sets on the Earth.
Etymology
The word "west" is a Germanic languages, German ...
and
Mid Wales
Mid Wales ( cy, Canolbarth Cymru or simply ''Y Canolbarth'', meaning "the midlands") or Central Wales refers to a region of Wales, encompassing its midlands, in-between North Wales and South Wales. The Mid Wales Regional Committee of the Senedd ...
.
* Zone 5: North/East of the A5, west of the A6, south of the
Solway Firth
The Solway Firth ( gd, Trà chd Romhra) is a firth that forms part of the border between England and Scotland, between Cumbria (including the Solway Plain) and Dumfries and Galloway. It stretches from St Bees Head, just south of Whitehaven in ...
/
Eden Estuary
The River Eden is a river in Fife in Scotland, and is one of Fife's two principal rivers, along with the Leven. It is nearly long and has a fall of around . It flows from Burnside, near the border with Perth & Kinross, then slowly across the ...
covering
North Wales
, area_land_km2 = 6,172
, postal_code_type = Postcode
, postal_code = LL, CH, SY
, image_map1 = Wales North Wales locator map.svg
, map_caption1 = Six principal areas of Wales common ...
, North
Midlands
The Midlands (also referred to as Central England) are a part of England that broadly correspond to the Kingdom of Mercia of the Early Middle Ages, bordered by Wales, Northern England and Southern England. The Midlands were important in the Ind ...
, western
Leicestershire
Leicestershire ( ; postal abbreviation Leics.) is a ceremonial and non-metropolitan county in the East Midlands, England. The county borders Nottinghamshire to the north, Lincolnshire to the north-east, Rutland to the east, Northamptonshire t ...
,
Cheshire
Cheshire ( ) is a ceremonial and historic county in North West England, bordered by Wales to the west, Merseyside and Greater Manchester to the north, Derbyshire to the east, and Staffordshire and Shropshire to the south. Cheshire's county t ...
,
Cumbria
Cumbria ( ) is a ceremonial and non-metropolitan county in North West England, bordering Scotland. The county and Cumbria County Council, its local government, came into existence in 1974 after the passage of the Local Government Act 1972. Cumb ...
and western
Lancashire
Lancashire ( , ; abbreviated Lancs) is the name of a historic county, ceremonial county, and non-metropolitan county in North West England. The boundaries of these three areas differ significantly.
The non-metropolitan county of Lancashi ...
. In Central London, the A40 (Holborn Viaduct, Holborn, High Holborn and Oxford Street) provides a border between the 4 and 5 zones east of Marble Arch. The original A5 (now renumbered A5183) also provides such a border, and north of St Albans the original A6 (now renumbered A1081) provides an Eastern border.
* Zone 6: East of the A6 and A7, west of the A1 covering eastern
Lancashire
Lancashire ( , ; abbreviated Lancs) is the name of a historic county, ceremonial county, and non-metropolitan county in North West England. The boundaries of these three areas differ significantly.
The non-metropolitan county of Lancashi ...
,
North East England
North East England is one of nine official regions of England at the first level of ITL for statistical purposes. The region has three current administrative levels below the region level in the region; combined authority, unitary authorit ...
,
Yorkshire
Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...
,
Nottinghamshire
Nottinghamshire (; abbreviated Notts.) is a landlocked county in the East Midlands region of England, bordering South Yorkshire to the north-west, Lincolnshire to the east, Leicestershire to the south, and Derbyshire to the west. The traditi ...
, eastern
Leicestershire
Leicestershire ( ; postal abbreviation Leics.) is a ceremonial and non-metropolitan county in the East Midlands, England. The county borders Nottinghamshire to the north, Lincolnshire to the north-east, Rutland to the east, Northamptonshire t ...
and
Rutland
Rutland () is a ceremonial county and unitary authority in the East Midlands, England. The county is bounded to the west and north by Leicestershire, to the northeast by Lincolnshire and the southeast by Northamptonshire.
Its greatest len ...
, and the
Scottish Borders
The Scottish Borders ( sco, the Mairches, 'the Marches'; gd, Crìochan na h-Alba) is one of 32 council areas of Scotland. It borders the City of Edinburgh, Dumfries and Galloway, East Lothian, Midlothian, South Lanarkshire, West Lothi ...
and Lothians. Between St Albans and Luton, the original A6 (now renumbered A1081) provides the Western border of the 6-zone.
* Zone 7: North of the Solway Firth/Eden Estuary, west of the A7, south of the A8 covering
Dumfries and Galloway
Dumfries and Galloway ( sco, Dumfries an Gallowa; gd, Dùn Phrìs is Gall-Ghaidhealaibh) is one of 32 unitary council areas of Scotland and is located in the western Southern Uplands. It covers the counties of Scotland, historic counties of ...
,
Ayrshire
Ayrshire ( gd, Siorrachd Inbhir Àir, ) is a historic county and registration county in south-west Scotland, located on the shores of the Firth of Clyde. Its principal towns include Ayr, Kilmarnock and Irvine and it borders the counties of Re ...
Glasgow
Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...
south of the
Clyde Clyde may refer to:
People
* Clyde (given name)
* Clyde (surname)
Places
For townships see also Clyde Township
Australia
* Clyde, New South Wales
* Clyde, Victoria
* Clyde River, New South Wales
Canada
* Clyde, Alberta
* Clyde, Ontario, a tow ...
.
* Zone 8: North of the A8, west of the A9 covering northern Glasgow,
Argyll and Bute
Argyll and Bute ( sco, Argyll an Buit; gd, Earra-Ghà idheal agus Bòd, ) is one of 32 unitary authority council areas in Scotland and a lieutenancy area. The current lord-lieutenant for Argyll and Bute is Jane Margaret MacLeod (14 July 2020) ...
,
Highland
Highlands or uplands are areas of high elevation such as a mountainous region, elevated mountainous plateau or high hills. Generally speaking, upland (or uplands) refers to ranges of hills, typically from up to while highland (or highlands) is ...
and the
Western Isles
The Outer Hebrides () or Western Isles ( gd, Na h-Eileanan Siar or or ("islands of the strangers"); sco, Waster Isles), sometimes known as the Long Isle/Long Island ( gd, An t-Eilean Fada, links=no), is an island chain off the west coas ...
* Zone 9: North of the A8, east of the A9 covering
Fife
Fife (, ; gd, Fìobha, ; sco, Fife) is a council area, historic county, registration county and lieutenancy area of Scotland. It is situated between the Firth of Tay and the Firth of Forth, with inland boundaries with Perth and Kinross (i ...
Orkney
Orkney (; sco, Orkney; on, Orkneyjar; nrn, Orknøjar), also known as the Orkney Islands, is an archipelago in the Northern Isles of Scotland, situated off the north coast of the island of Great Britain. Orkney is 10 miles (16 km) north ...
and
Shetland
Shetland, also called the Shetland Islands and formerly Zetland, is a subarctic archipelago in Scotland lying between Orkney, the Faroe Islands and Norway. It is the northernmost region of the United Kingdom.
The islands lie about to the no ...
The first digit in the number of any road should be the number of the furthest-anticlockwise zone entered by that road. For example, the
A38 road
The A38, parts of which are known as Devon Expressway, Bristol Road and Gloucester Road, Bristol, Gloucester Road, is a major A-class trunk road in England.
The road runs from Bodmin in Cornwall to Mansfield in Nottinghamshire. It is long, mak ...
Bodmin
Bodmin () is a town and civil parish in Cornwall, England, United Kingdom. It is situated south-west of Bodmin Moor.
The extent of the civil parish corresponds fairly closely to that of the town so is mostly urban in character. It is bordere ...
to
Mansfield
Mansfield is a market town and the administrative centre of Mansfield District in Nottinghamshire, England. It is the largest town in the wider Mansfield Urban Area (followed by Sutton-in-Ashfield). It gained the Royal Charter of a market tow ...
starts in Zone 3, and is therefore numbered with an A3x number, even though it passes through Zones 4 and 5 to end in Zone 6. Additionally, the A1 in
Newcastle upon Tyne
Newcastle upon Tyne ( RP: , ), or simply Newcastle, is a city and metropolitan borough in Tyne and Wear, England. The city is located on the River Tyne's northern bank and forms the largest part of the Tyneside built-up area. Newcastle is ...
has moved twice. Originally along the Great North Road, it then moved to the
Tyne Tunnel
The Tyne Tunnel is the name given to two 2-lane vehicular toll tunnels under the River Tyne in North East England. Originally opened in 1967 and expanded in 2011, the tunnels connect the town of Jarrow on the south bank of the river with North S ...
, causing some of the roads in Zone 1 to lie in Zone 6. The designated A1 later moved to the western bypass around the city, and roads between the two found themselves back in Zone 1. For the most part the roads affected retained their original numbers throughout.
Elsewhere when single-digit roads were bypassed, roads were often re-numbered in keeping with the original zone boundaries.
In a limited number of cases road numbering does not necessarily follow the rules with some anomalously numbered.
Motorways
Motorways
A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway and expressway. Other similar terms i ...
first came to Britain over three decades after the advent of the A-road numbering event, and as a result required a new numbering system. They were given an M prefix, and in England and Wales a numbering system of their own not coterminous with that of the A-road network, though based on the same principle of zones. Running clockwise from the M1 the zones were defined for Zones 1 to 4 based on the proposed M2, M3 and
M4 motorway
The M4, originally the London-South Wales Motorway, is a motorway in the United Kingdom running from west London to southwest Wales. The English section to the Severn Bridge was constructed between 1961 and 1971; the Welsh element was largely ...
s. The M5 and M6 numbers were reserved for the other two planned long distance motorways. The
Preston Bypass
The Preston Bypass was the United Kingdom’s first motorway. It was designed and engineered by Lancashire County Council surveyor James Drake as part of a larger initiative to create a north-south motorway network that would later form part ...
, the UK's first motorway section, should have been numbered A6(M) under the scheme decided upon, but it was decided to keep the number M6 as had already been applied. The first full-length motorway in the UK was the
M1 motorway
The M1 motorway connects London to Leeds, where it joins the A1(M) near Aberford, to connect to Newcastle. It was the first inter-urban motorway to be completed in the UK; the first motorway in the country was the Preston By-pass, which lat ...
.
Shorter motorways typically take their numbers from a parent motorway in contravention of the zone system, explaining the apparently anomalous numbers of the M48 and M49 motorways as spurs of the M4, and M271 and M275 motorways as those of the M27.
This numbering system was devised in 1958–59 by the then Ministry of Transport and Civil Aviation, and applied only in England and Wales. It was decided to reserve the numbers 7, 8 & 9 for Scotland. In Scotland, where roads were the responsibility of the
Scottish Office
The Scottish Office was a department of the Government of the United Kingdom from 1885 until 1999, exercising a wide range of government functions in relation to Scotland under the control of the Secretary of State for Scotland. Following the e ...
(Scottish Government after 1999), the decision was taken to adopt a scheme whereby motorways took the numbers of the all-purpose routes they replaced. As a result, there is no M7 (as no motorway follows the A7), and when the A90 was re-routed to replace the A85 south of
Perth
Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...
In England and Wales, the six single-digit numbers reflect the traditionally most important radial routes coming out of London. Starting with the A1 which heads due north, numbers were allocated sequentially in a clockwise direction, thus:
* A1
London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...
to
Edinburgh
Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...
, (Also known as the Great North Road), but most of the road is bypassed by the M1 and many sections have been upgraded to
A1(M)
A1(M) is the designation given to a series of four separate motorway sections in England. Each section is an upgrade to a section of the A1, a major north–south road which connects London, the capital of England, with Edinburgh, the capit ...
Dover
Dover () is a town and major ferry port in Kent, South East England. It faces France across the Strait of Dover, the narrowest part of the English Channel at from Cap Gris Nez in France. It lies south-east of Canterbury and east of Maidstone ...
, (The southern part of Watling Street, also known as the Dover Road).
* A3 London to
Portsmouth
Portsmouth ( ) is a port and city in the ceremonial county of Hampshire in southern England. The city of Portsmouth has been a unitary authority since 1 April 1997 and is administered by Portsmouth City Council.
Portsmouth is the most dens ...
, (Also known as the Portsmouth Road)
* A4 London to
Avonmouth
Avonmouth is a port and outer suburb of Bristol, England, facing two rivers: the reinforced north bank of the final stage of the Avon which rises at sources in Wiltshire, Gloucestershire and Somerset; and the eastern shore of the Severn Estuar ...
, (Also known as the Great West Road or the Bath Road), although this route is not used as a long-distance road since the completion of the M4.
* A5 London to
Holyhead
Holyhead (,; cy, Caergybi , "Cybi's fort") is the largest town and a community in the county of Isle of Anglesey, Wales, with a population of 13,659 at the 2011 census. Holyhead is on Holy Island, bounded by the Irish Sea to the north, and is ...
Luton
Luton () is a town and unitary authority with borough status, in Bedfordshire, England. At the 2011 census, the Luton built-up area subdivision had a population of 211,228 and its built-up area, including the adjacent towns of Dunstable an ...
to
Carlisle
Carlisle ( , ; from xcb, Caer Luel) is a city that lies within the Northern England, Northern English county of Cumbria, south of the Anglo-Scottish border, Scottish border at the confluence of the rivers River Eden, Cumbria, Eden, River C ...
(The A6 originally started in Barnet on the old A1. When the A1 was moved onto the Barnet Bypass in the 1950s, the A6 was cut back to the A1/A1(M) junction (later A1/M25 junction). Further renumbering in the St Albans area means that it now starts in Luton town centre. The old route is numbered as A1081).
Similarly, in Scotland, important roads radiating from Edinburgh have single-digit numbers, thus:
* A7
Edinburgh
Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...
to
Carlisle
Carlisle ( , ; from xcb, Caer Luel) is a city that lies within the Northern England, Northern English county of Cumbria, south of the Anglo-Scottish border, Scottish border at the confluence of the rivers River Eden, Cumbria, Eden, River C ...
, although the M74 and M8 motorways now form the primary link.
* A8 Edinburgh to
Greenock
Greenock (; sco, Greenock; gd, Grianaig, ) is a town and administrative centre in the Inverclyde council areas of Scotland, council area in Scotland, United Kingdom and a former burgh of barony, burgh within the Counties of Scotland, historic ...
, which formerly linked Edinburgh to
Glasgow
Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...
, however it now has a 25-mile gap, where it is replaced by the M8.
* A9
Falkirk
Falkirk ( gd, An Eaglais Bhreac, sco, Fawkirk) is a large town in the Central Lowlands of Scotland, historically within the county of Stirlingshire. It lies in the Forth Valley, northwest of Edinburgh and northeast of Glasgow.
Falkirk had a ...
to
Scrabster
Scrabster ( sco, Scraibster, gd, Sgrabastair/Sgrabstal) is a small settlement on Thurso Bay in Caithness on the north coast of Scotland. It is some from Thurso, from Wick, from Inverness and 271.7 miles (437.2 km) from Edinburgh. Scra ...
. Originally Edinburgh to
Inverness
Inverness (; from the gd, Inbhir Nis , meaning "Mouth of the River Ness"; sco, Innerness) is a city in the Scottish Highlands. It is the administrative centre for The Highland Council and is regarded as the capital of the Highlands. Histori ...
Wick
Wick most often refers to:
* Capillary action ("wicking")
** Candle wick, the cord used in a candle or oil lamp
** Solder wick, a copper-braided wire used to desolder electronic contacts
Wick or WICK may also refer to:
Places and placename ...
on 16 May 1935, and later cut back at the southern end because of the construction of the main runway at
Edinburgh Airport
Edinburgh Airport is an airport located in the Ingliston area of Edinburgh, Scotland. It was the busiest airport in Scotland in 2019, handling over 14.7 million passengers. It was also the sixth-busiest airport in the United Kingdom by t ...
on top of it. As such, the route from Edinburgh is now replaced by the M9 (with the M90 across the
Queensferry Crossing
The Queensferry Crossing (formerly the Forth Replacement Crossing) is a road bridge in Scotland. It was built alongside the existing Forth Road Bridge and carries the M90 motorway across the Firth of Forth between Edinburgh, at South Queensfe ...
as an alternative to
Perth
Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...
). On 1 April 1997, the A9 was diverted to
Thurso
Thurso (pronounced ; sco, Thursa, gd, Inbhir Theòrsa ) is a town and former burgh on the north coast of the Highland council area of Scotland. Situated in the historical County of Caithness, it is the northernmost town on the island of Great ...
and Scrabster at the northern end.
While these routes remain the basis for the numbering of the A road network, they are no longer necessarily major roads, having been bypassed by motorways or other changes to the road network.
Other A roads
These radials are supplemented by two-digit codes which are routes that ''may'' be slightly less important, but may still be classified as trunk routes, although many of these routes have lost a lot of their significance due to motorway bypasses, or the upgrading of other A-roads. These routes are not all centred on London, but as far as possible follow the general principle that their number locates them radially clockwise from the associated single digit route. For example, the A10 (London to King's Lynn) is the first main route clockwise from the A1, the A11 (London to Norwich) is the next, then the A12 (London to Great Yarmouth) and the A13 (London to Shoeburyness); the next radial is the A2, followed by the A20 (London to Dover), and so on. These roads have been numbered either outwards from or clockwise around their respective hubs, depending on their alignment.
The system continues to three and four digit numbers which further split and criss-cross the radials. Lower numbers originate closer to London than higher numbered ones. As roads have been improved since the scheme commenced, some roads with 3 or 4 digit numbers have increased in significance, for example the
A127
The A127, also known as the Southend Arterial Road, is a major road in Essex, England. It was constructed as a new arterial road project in the 1920s, linking Romford with Southend-on-Sea, replacing the older A13. Formerly classified as a tr ...
, A1079 and A414. New routes have also been allocated 3 or 4 digit numbers, for example the Edinburgh City Bypass is the
A720
The Edinburgh City Bypass, designated as A720, is one of the most important trunk roads in Scotland. Circling around the south of Edinburgh, as the equivalent of a ring road for the coastal city, it links together the A1 towards north-east Eng ...
.
The Major Road Network is a proposed classification of major local-authority controlled A roads that the government committed to implementing in 2017, with the aim of better targeting road funding.
Some A roads are designated trunk roads, which implies that central government rather than local government has responsibility for them. A more recent classification is that of
primary route
The United Kingdom has a network of roads, of varied quality and capacity, totalling about . Road distances are shown in miles or yards and UK speed limits are indicated in miles per hour (mph) or by the use of the national speed limit (NSL) sy ...
s, the category of recommended routes for long-distance traffic. Primary routes include both trunk and non-trunk roads.
Motorway sections
Some sections of A roads have been improved to the same standard as motorways, but do not completely replace the existing road; they form a higher standard part of the route for those which are not excluded. These sections retain the same number but are suffixed with (M), for example the
A1(M)
A1(M) is the designation given to a series of four separate motorway sections in England. Each section is an upgrade to a section of the A1, a major north–south road which connects London, the capital of England, with Edinburgh, the capit ...
and A404(M). There have been occasions where this designation has been used to indicate motorway bypasses of an existing road, but the original retains the A road designation, for example
A3(M)
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 ...
,
A329(M)
The A329(M) is a motorway in Berkshire, England. It is 4 miles (6.4 km) long and runs from the west of Bracknell to the north west of Winnersh. It is one of a small number of parts of the motorway system in England that are managed by ...
,
A38(M)
The A38(M), commonly known as the Aston Expressway, is a motorway in Birmingham, England. It is long and was opened on 24 May 1972.A48(M) and
A627(M)
The A627(M) is a motorway that runs between Chadderton and Rochdale in Greater Manchester, England. It is long and connects these two towns to the M62. It opened in 1972.
Route
Heading north, the road starts as a two-lane dual carriageway on ...
.
Other classifications
B roads are numbered distributor roads, which have lower traffic densities than the main trunk roads, or A roads. This classification has nothing to do with the width or quality of the physical road, and B roads can range from dual carriageways to single track roads with passing places. B roads follow the same numbering scheme as A roads, but almost always have 3- and 4-digit designations. Many 3-digit B roads outside the
London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...
area are former A roads which have been downgraded owing to new road construction; others may link smaller settlements to A roads.
Despite numerous large roads in Great Britain being part of the
International E-road network
The international E-road network is a numbering system for roads in Europe developed by the United Nations Economic Commission for Europe (UNECE). The network is numbered from E1 up and its roads cross national borders. It also reaches Centr ...
, no road that forms part of this network is signposted as such and only the road's national designation is shown. The same is true in Northern Ireland.
Minor roads
Roads and lanes with yet lower traffic densities are designated as ''unclassified'' roads commonly using C, D and U prefixes but, while these are numbered, in general this is done for use by the local authorities who are responsible for maintaining them and the non-unique numbering is in a local series which usually does not appear on road signs; use of local numbers on signs in England is "not advised". Exceptions to this are known however both in the form of numbers on signs and past use of prefixes H and V on signs in
Milton Keynes
Milton Keynes ( ) is a city and the largest settlement in Buckinghamshire, England, about north-west of London. At the 2021 Census, the population of its urban area was over . The River Great Ouse forms its northern boundary; a tributary ...
planning applications
Planning permission or developmental approval refers to the approval needed for construction or expansion (including significant renovation), and sometimes for demolition, in some jurisdictions. It is usually given in the form of a building perm ...
, including the creation of a new vehicular access onto a highway. The letter Q is used for many important unclassified roads in
Fife
Fife (, ; gd, Fìobha, ; sco, Fife) is a council area, historic county, registration county and lieutenancy area of Scotland. It is situated between the Firth of Tay and the Firth of Forth, with inland boundaries with Perth and Kinross (i ...
.
In London,
Cycleways
Cycling infrastructure is all infrastructure cyclists are allowed to use. Bikeways include bike paths, bike lanes, cycle tracks, rail trails and, where permitted, sidewalks. Roads used by motorists are also cycling infrastructure, except wher ...
are using the C prefix and marked using pale green signs. There are also some CS prefixes for Cycle Superhighways, marked using magenta signs, but these are being phased out.
Numbering
There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator. The schemes can be considered to be examples of a primary key of a database management ...