Great Britain road numbering scheme
Encyclopedia
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 system table, whose table definitions require a...
used to classify
Categorization
Categorization is the process in which ideas and objects are recognized, differentiated and understood. Categorization implies that objects are grouped into categories, usually for some specific purpose. Ideally, a category illuminates a relationship between the subjects and objects of knowledge...
and identify all roads in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
. Each road is given a single letter, which represents the road's category, and a subsequent number, with a length of between 1 and 4 digits. Originally introduced to arrange funding allocations, the numbers soon became used on maps and as a method of navigation. Two schemes exist: one for motorways, and another for non-motorway roads.
The scheme applies only to England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
and Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
. Alternative systems are used in Northern Ireland
Northern Ireland
Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...
(see Roads in Northern Ireland
Roads in Northern Ireland
The main roads in Northern Ireland, which connect well with those in the south, are classified "M"/"A"/"B" as in Great Britain. Whereas the roads in Great Britain are numbered according to a zonal system, there is no available explanation for the allocation of road numbers in Northern Ireland,...
), the Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...
(see Roads in the Isle of Man) and Jersey
Jersey
Jersey, officially the Bailiwick of Jersey is a British Crown Dependency off the coast of Normandy, France. As well as the island of Jersey itself, the bailiwick includes two groups of small islands that are no longer permanently inhabited, the Minquiers and Écréhous, and the Pierres de Lecq and...
, Channel Islands
Channel Islands
The Channel Islands are an archipelago of British Crown Dependencies in the English Channel, off the French coast of Normandy. They include two separate bailiwicks: the Bailiwick of Guernsey and the Bailiwick of Jersey...
. All of these numbering schemes use identical basic conventions and road-sign designs.
History
Initial work on classification began in 1913 by the government's Roads Board to determine the quality and usage of British roads. This work was interrupted by the First World War and did not resume until the Ministry of TransportDepartment for Transport
In the United Kingdom, the Department for Transport is the government department responsible for the English transport network and a limited number of transport matters in Scotland, Wales and Northern Ireland which are not devolved...
was formed in 1919 and given authority to classify highways, to allocate funding for road maintenance, authority for which was granted by section 17 (2) of the Ministry of Transport Act 1919. It created a classification system for the important routes connecting large population centres or for through traffic, which were designated as Class I, and roads of lesser importance, which were designated as Class II. The definitive list of these roads published on 1 April 1923 following consultations with local authorities. 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, converting them into 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 as it was a period of heavy 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 the major routes and a new classification system was created to identify these routes. Originally these numbers beginning in T were to be made public, however this was eventually deemed unnecessary.
With the introduction of motorways in the late 1950s, a new classification 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 this renumbering - some retained their existing number as non-primary A roads (e.g. the A40
A40 road
The A40 is a major trunk road connecting London to Fishguard, Wales and officially called The London to Fishguard Trunk Road in all legal documents and Acts...
running alongside the M40
M40 motorway
The M40 motorway is a motorway in the British transport network that forms a major part of the connection between London and Birmingham. Part of this road forms a section of the unsigned European route E05...
), 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
A38 road
The A38, part of which is also known as the Devon Expressway, is a major A-class trunk road in England.The road runs from Bodmin in Cornwall to Mansfield in Nottinghamshire. It is long, making it one of the longest A-roads in England. It was formerly known as the Leeds — Exeter Trunk Road,...
, which has been replaced by the M5
M5 motorway
The M5 is a motorway in England. It runs from a junction with the M6 at West Bromwich near Birmingham to Exeter in Devon. Heading south-west, the M5 runs east of West Bromwich and west of Birmingham through Sandwell Valley...
between Tiverton and Exeter
Exeter
Exeter is a historic city in Devon, England. It lies within the ceremonial county of Devon, of which it is the county town as well as the home of Devon County Council. Currently the administrative area has the status of a non-metropolitan district, and is therefore under the administration of the...
). Occasionally the new motorway would take the name of the old A-road rather than having its own number. The most notable example of this is the A1(M).
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 LondonLondon
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
. In Scotland the same scheme is centred on Edinburgh
Edinburgh
Edinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...
. In both cases the main single-digit roads normally define the zone boundaries, with the exception of Zones 1 and 2.
- Zone 1: North of the ThamesRiver ThamesThe River Thames flows through southern England. It is the longest river entirely in England and the second longest in the United Kingdom. While it is best known because its lower reaches flow through central London, the river flows alongside several other towns and cities, including Oxford,...
, east of the A1 covering Greater LondonGreater LondonGreater London is the top-level administrative division of England covering London. It was created in 1965 and spans the City of London, including Middle Temple and Inner Temple, and the 32 London boroughs. This territory is coterminate with the London Government Office Region and the London...
, EssexEssexEssex is a ceremonial and non-metropolitan county in the East region of England, and one of the home counties. It is located to the northeast of Greater London. It borders with Cambridgeshire and Suffolk to the north, Hertfordshire to the west, Kent to the South and London to the south west...
, CambridgeshireCambridgeshireCambridgeshire is a county in England, bordering Lincolnshire to the north, Norfolk to the northeast, Suffolk to the east, Essex and Hertfordshire to the south, and Bedfordshire and Northamptonshire to the west...
, East AngliaEast AngliaEast Anglia is a traditional name for a region of eastern England, named after an ancient Anglo-Saxon kingdom, the Kingdom of the East Angles. The Angles took their name from their homeland Angeln, in northern Germany. East Anglia initially consisted of Norfolk and Suffolk, but upon the marriage of...
, LincolnshireLincolnshireLincolnshire is a county in the east of England. It borders Norfolk to the south east, Cambridgeshire to the south, Rutland to the south west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north west, and the East Riding of Yorkshire to the north. It also borders...
, parts of YorkshireYorkshireYorkshire is a historic county of northern England and the largest in the United Kingdom. Because of its great size in comparison to other English counties, functions have been increasingly undertaken over time by its subdivisions, which have also been subject to periodic reform...
, ClevelandCleveland, EnglandCleveland is an area in the north east of England. Its name means literally "cliff-land", referring to its hilly southern areas, which rise to nearly...
, Tyne and WearTyne and WearTyne and Wear is a metropolitan county in north east England around the mouths of the Rivers Tyne and Wear. It came into existence as a metropolitan county in 1974 after the passage of the Local Government Act 1972...
, NorthumberlandNorthumberlandNorthumberland is the northernmost ceremonial county and a unitary district in North East England. For Eurostat purposes Northumberland is a NUTS 3 region and is one of three boroughs or unitary districts that comprise the "Northumberland and Tyne and Wear" NUTS 2 region...
, parts of the Scottish BordersScottish BordersThe Scottish Borders is one of 32 local government council areas of Scotland. It is bordered by Dumfries and Galloway in the west, South Lanarkshire and West Lothian in the north west, City of Edinburgh, East Lothian, Midlothian to the north; and the non-metropolitan counties of Northumberland...
, East LothianEast LothianEast Lothian is one of the 32 council areas of Scotland, and a lieutenancy Area. It borders the City of Edinburgh, Scottish Borders and Midlothian. Its administrative centre is Haddington, although its largest town is Musselburgh....
and on up to EdinburghEdinburghEdinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area... - Zone 2: South of the Thames, east of the A3 covering SurreySurreySurrey is a county in the South East of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire and Berkshire. The historic county town is Guildford. Surrey County Council sits at Kingston upon Thames, although this has been part of...
, SussexSussexSussex , from the Old English Sūþsēaxe , is an historic county in South East England corresponding roughly in area to the ancient Kingdom of Sussex. It is bounded on the north by Surrey, east by Kent, south by the English Channel, and west by Hampshire, and is divided for local government into West...
and KentKentKent is a county in southeast England, and is one of the home counties. It borders East Sussex, Surrey and Greater London and has a defined boundary with Essex in the middle of the Thames Estuary. The ceremonial county boundaries of Kent include the shire county of Kent and the unitary borough of... - Zone 3: North/West of the A3, south of the A4 covering HampshireHampshireHampshire is a county on the southern coast of England in the United Kingdom. The county town of Hampshire is Winchester, a historic cathedral city that was once the capital of England. Hampshire is notable for housing the original birthplaces of the Royal Navy, British Army, and Royal Air Force...
(excluding PortsmouthPortsmouthPortsmouth is the second largest city in the ceremonial county of Hampshire on the south coast of England. Portsmouth is notable for being the United Kingdom's only island city; it is located mainly on Portsea Island...
), the Isle of WightIsle of WightThe Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
, DorsetDorsetDorset , is a county in South West England on the English Channel coast. The county town is Dorchester which is situated in the south. The Hampshire towns of Bournemouth and Christchurch joined the county with the reorganisation of local government in 1974...
and South West EnglandSouth West EnglandSouth West England is one of the regions of England defined by the Government of the United Kingdom for statistical and other purposes. It is the largest such region in area, covering and comprising Bristol, Gloucestershire, Somerset, Dorset, Wiltshire, Devon, Cornwall and the Isles of Scilly. ... - Zone 4: North of the A4, south/west of the A5 covering the southSouth MidlandsThe South Midlands is a notional area of England. According to one definition, it is the southern portion of the East Midlands together with the northern portion of South East England and the western portion of the East of England, and just as there is no agreed definition for these areas,...
and West MidlandsWest Midlands (region)The West Midlands is an official region of England, covering the western half of the area traditionally known as the Midlands. It contains the second most populous British city, Birmingham, and the larger West Midlands conurbation, which includes the city of Wolverhampton and large towns of Dudley,...
, OxfordshireOxfordshireOxfordshire is a county in the South East region of England, bordering on Warwickshire and Northamptonshire , Buckinghamshire , Berkshire , Wiltshire and Gloucestershire ....
, GloucestershireGloucestershireGloucestershire 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....
, BuckinghamshireBuckinghamshireBuckinghamshire is a ceremonial and non-metropolitan home county in South East England. The county town is Aylesbury, the largest town in the ceremonial county is Milton Keynes and largest town in the non-metropolitan county is High Wycombe....
and southSouth WalesSouth Wales is an area of Wales bordered by England and the Bristol Channel to the east and south, and Mid Wales and West Wales to the north and west. The most densely populated region in the south-west of the United Kingdom, it is home to around 2.1 million people and includes the capital city of...
, westWest WalesWest Wales is the western area of Wales.Some definitions of West Wales include only Pembrokeshire, Ceredigion and Carmarthenshire, an area which historically comprised the Welsh principality of Deheubarth., an area called "South West Wales" in the Nomenclature of Territorial Units for Statistics....
and Mid WalesMid WalesMid Wales is the name given to the central region of Wales. The Mid Wales Regional Committee of the National Assembly for Wales covered the counties of Ceredigion and Powys and the area of Gwynedd that had previously been the district of Meirionydd. A similar definition is used by the BBC...
. - Zone 5: North/East of the A5, west of the A6, south of the Solway FirthSolway FirthThe Solway Firth is a firth that forms part of the border between England and Scotland, between Cumbria and Dumfries and Galloway. It stretches from St Bees Head, just south of Whitehaven in Cumbria, to the Mull of Galloway, on the western end of Dumfries and Galloway. The Isle of Man is also very...
/Eden Estuary covering North WalesNorth WalesNorth Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...
, North MidlandsEnglish MidlandsThe Midlands, or the English Midlands, is the traditional name for the area comprising central England that broadly corresponds to the early medieval Kingdom of Mercia. It borders Southern England, Northern England, East Anglia and Wales. Its largest city is Birmingham, and it was an important...
, CheshireCheshireCheshire is a ceremonial county in North West England. Cheshire's county town is the city of Chester, although its largest town is Warrington. Other major towns include Widnes, Congleton, Crewe, Ellesmere Port, Runcorn, Macclesfield, Winsford, Northwich, and Wilmslow...
, CumbriaCumbriaCumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in...
and LancashireLancashireLancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston...
. 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 North East EnglandNorth East EnglandNorth East England is one of the nine official regions of England. It covers Northumberland, County Durham, Tyne and Wear, and Teesside . The only cities in the region are Durham, Newcastle upon Tyne and Sunderland...
, YorkshireYorkshireYorkshire is a historic county of northern England and the largest in the United Kingdom. Because of its great size in comparison to other English counties, functions have been increasingly undertaken over time by its subdivisions, which have also been subject to periodic reform...
, Scottish BordersScottish BordersThe Scottish Borders is one of 32 local government council areas of Scotland. It is bordered by Dumfries and Galloway in the west, South Lanarkshire and West Lothian in the north west, City of Edinburgh, East Lothian, Midlothian to the north; and the non-metropolitan counties of Northumberland...
and the 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 GallowayDumfries and GallowayDumfries and Galloway is one of 32 unitary council areas of Scotland. It was one of the nine administrative 'regions' of mainland Scotland created in 1975 by the Local Government etc. Act 1973...
, AyrshireAyrshireAyrshire is a registration county, and former administrative county in south-west Scotland, United Kingdom, located on the shores of the Firth of Clyde. Its principal towns include Ayr, Kilmarnock and Irvine. The town of Troon on the coast has hosted the British Open Golf Championship twice in the...
and Central ScotlandCentral BeltThe Central Belt of Scotland is a common term used to describe the area of highest population density within Scotland. Despite the name, it is not geographically central but is nevertheless situated at the 'waist' of Scotland on a conventional map and the term 'central' is used in many local... - Zone 8: North of the A8, west of the A9 covering HighlandHighland (council area)Highland is a council area in the Scottish Highlands and is the largest local government area in both Scotland and the United Kingdom as a whole. It shares borders with the council areas of Moray, Aberdeenshire, Perth and Kinross, and Argyll and Bute. Their councils, and those of Angus and...
and the Western Isles - Zone 9: North of the A8, east of the A9 covering North East Scotland, Orkney and Shetland
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
A38 road
The A38, part of which is also known as the Devon Expressway, is a major A-class trunk road in England.The road runs from Bodmin in Cornwall to Mansfield in Nottinghamshire. It is long, making it one of the longest A-roads in England. It was formerly known as the Leeds — Exeter Trunk Road,...
, a trunk road
Trunk road
A trunk road, trunk highway, or strategic road is a major road—usually connecting two or more cities, ports, airports, and other things.—which is the recommended route for long-distance and freight traffic...
running from Bodmin
Bodmin
Bodmin is a civil parish and major town in Cornwall, England, United Kingdom. It is situated in the centre of the county southwest of Bodmin Moor.The extent of the civil parish corresponds fairly closely to that of the town so is mostly urban in character...
to Mansfield
Mansfield
Mansfield is a town in Nottinghamshire, England. It is the main town in the Mansfield local government district. Mansfield is a part of the Mansfield Urban Area....
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
Newcastle upon Tyne is a city and metropolitan borough of Tyne and Wear, in North East England. Historically a part of Northumberland, it is situated on the north bank of the River Tyne...
has moved twice. Originally along the Great North Road, it then moved to the Tyne Tunnel
Tyne Tunnel
The Tyne Tunnel is a the name given to two two-lane toll vehicular tunnels under the River Tyne in North East England. Completed in 1967 and 2011 respectively, they connect the town of Jarrow on the south bank of the river with North Shields and Howdon on the north...
, causing some of the roads in Zone 1 to now be in Zone 6, and some were renumbered. It was later moved to the western bypass around the city, and roads between the two found themselves back in Zone 1, and were renumbered wholesale. This did not always happen, however, and 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 doesn't necessarily follow the rules with some anomalously numbered
Anomalously numbered roads in Great Britain
In the Great Britain road numbering scheme, Great Britain is divided into numbered zones, the boundaries of which are usually defined by single-digit roads. The first digit of a road's number should be the number of the zone it occupies...
.
Motorways
Motorways 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 M1M1 motorway
The M1 is a north–south motorway in England primarily connecting London to Leeds, where it joins the A1 near Aberford. While the M1 is considered to be the first inter-urban motorway to be completed in the United Kingdom, the first road to be built to motorway standard in the country was the...
the zones were defined for Zones 1 to 4 based on the proposed M2, M3 and M4 motorway
M4 motorway
The M4 motorway links London with South Wales. It is part of the unsigned European route E30. Other major places directly accessible from M4 junctions are Reading, Swindon, Bristol, Newport, Cardiff and Swansea...
s. The M5
M5 motorway
The M5 is a motorway in England. It runs from a junction with the M6 at West Bromwich near Birmingham to Exeter in Devon. Heading south-west, the M5 runs east of West Bromwich and west of Birmingham through Sandwell Valley...
and M6
M6 motorway
The M6 motorway runs from junction 19 of the M1 at the Catthorpe Interchange, near Rugby via Birmingham then heads north, passing Stoke-on-Trent, Manchester, Preston, Carlisle and terminating at the Gretna junction . Here, just short of the Scottish border it becomes the A74 which continues to...
numbers were reserved for the other two planned long distance motorways. The Preston Bypass, 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
M1 motorway
The M1 is a north–south motorway in England primarily connecting London to Leeds, where it joins the A1 near Aberford. While the M1 is considered to be the first inter-urban motorway to be completed in the United Kingdom, the first road to be built to motorway standard in the country was the...
.
Shorter motorways typically take their numbers from a parent motorway in violation of the zone system, explaining the apparently anomalous numbers
Anomalously numbered roads in Great Britain
In the Great Britain road numbering scheme, Great Britain is divided into numbered zones, the boundaries of which are usually defined by single-digit roads. The first digit of a road's number should be the number of the zone it occupies...
of the M48
M48 motorway
The M48 is a motorway in Great Britain joining Gloucestershire and Monmouthshire over the original Severn Bridge. The M48 is anomalously numbered, as it is entirely to the west of the M5 motorway and its number should really therefore begin with 5.-Route:...
and M49
M49 motorway
The M49 motorway is a 5 mile motorway west of Bristol, England, that forms a shortcut between the M5 motorway and the Second Severn Bridge on the M4 motorway. It was constructed in 1996, at the same time as the bridge and is unique as it is only accessible from other motorways...
motorways as spurs
Spur route
A spur route is a short road forming a branch from a longer, more important route . A bypass or beltway is never considered a true spur route as it typically reconnects with the major road...
of the M4, and M271
M271 motorway
The M271 is a motorway near Southampton in Hampshire, England. It is long. Construction began in 1973 and it opened in 1975. It provides part of the route to Southampton Docks from the M27.-Route:...
and M275
M275 motorway
The M275 is a long, dual three-lane motorway in the county of Hampshire, southern England. It is the principal route for entering and leaving Portsmouth. It continues as the A3 into Portsmouth, and meets the M27 at its northern terminus...
motorways as those of the M27
M27 motorway
The M27 is a motorway in Hampshire, England. It is long and runs west-east from Cadnam to Portsmouth. It was opened in stages between 1975 and 1983. It is however unfinished as an extension to the east was planned...
.
This numbering system was devised in 1958-9 by the then Ministry of Transport and Civil Aviation
Department for Transport
In the United Kingdom, the Department for Transport is the government department responsible for the English transport network and a limited number of transport matters in Scotland, Wales and Northern Ireland which are not devolved...
, 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
Scottish Office
The Scottish Office was a department of the United Kingdom Government 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...
(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
A90 road
The A90 road is a major north to south road in eastern Scotland, running from Edinburgh to Fraserburgh in Aberdeenshire.From Edinburgh, it travels west and over the Forth Road Bridge, before turning into the M90 motorway. At Perth, the M90 again becomes the A90, now running north east to Dundee...
was re-routed to replace the A85
A85 road
The A85 is a major road in Scotland. It runs east from Oban along the south bank of Loch Etive, through Lochawe and Tyndrum, Crianlarich, Lochearnhead, St Fillans and Crieff before passing through Perth, where it crosses the River Tay via Perth Bridge. Its name between the latter two locations is...
south of Perth
Perth, Scotland
Perth is a town and former city and royal burgh in central Scotland. Located on the banks of the River Tay, it is the administrative centre of Perth and Kinross council area and the historic county town of Perthshire...
, the short M85 became part of the M90
M90 motorway
The M90 is a motorway in Scotland. It runs from Inverkeithing, at the north end of the Forth Road Bridge, to Perth, passing Dunfermline, Cowdenbeath and Kinross on the way...
.
Single-digit A roads
In England and Wales the main roads radiating from London have single-digit numbers, starting with the A1 which heads due north. The numbering continues sequentially in a clockwise direction, thus:- A1 LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to EdinburghEdinburghEdinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...
, (previously known as the Great North Road) - A2A2 road (Great Britain)The A2 is a major road in southern England, connecting London with the English Channel port of Dover in Kent. This route has always been of importance as a connection between the British capital of London and sea trade routes to Continental Europe...
LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to DoverDoverDover is a town and major ferry port in the home county of Kent, in South East England. It faces France across the narrowest part of the English Channel, and lies south-east of Canterbury; east of Kent's administrative capital Maidstone; and north-east along the coastline from Dungeness and Hastings... - A3 LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to PortsmouthPortsmouthPortsmouth is the second largest city in the ceremonial county of Hampshire on the south coast of England. Portsmouth is notable for being the United Kingdom's only island city; it is located mainly on Portsea Island... - A4 LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to AvonmouthAvonmouthAvonmouth is a port and suburb of Bristol, England, located on the Severn Estuary, at the mouth of the River Avon.The council ward of Avonmouth also includes Shirehampton and the western end of Lawrence Weston.- Geography :... - A5 LondonLondonLondon is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to HolyheadHolyheadHolyhead is the largest town in the county of Anglesey in the North Wales. It is also a major port adjacent to the Irish Sea serving Ireland.... - A6 LutonLutonLuton is a large town and unitary authority of Bedfordshire, England, 30 miles north of London. Luton and its near neighbours, Dunstable and Houghton Regis, form the Luton/Dunstable Urban Area with a population of about 250,000....
to Carlisle (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/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 EdinburghEdinburghEdinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...
to Carlisle - A8 EdinburghEdinburghEdinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...
to GreenockGreenockGreenock is a town and administrative centre in the Inverclyde council area in United Kingdom, and a former burgh within the historic county of Renfrewshire, located in the west central Lowlands of Scotland...
, this effectively links Edinburgh to GlasgowGlasgowGlasgow is the largest city in Scotland and third most populous in the United Kingdom. The city is situated on the River Clyde in the country's west central lowlands...
now replaced by the M8. - A9 FalkirkFalkirkFalkirk is a town in the Central Lowlands of Scotland. It lies in the Forth Valley, almost midway between the two most populous cities of Scotland; north-west of Edinburgh and north-east of Glasgow....
to ThursoThurso-Facilities:Offices of the Highland Council are located in the town, as is the main campus of North Highland College, formerly Thurso College. This is one of several partner colleges which constitute the UHI Millennium Institute, and offers several certificate, diploma and degree courses from...
(Originally Edinburgh to InvernessInvernessInverness is a city in the Scottish Highlands. It is the administrative centre for the Highland council area, and is regarded as the capital of the Highlands of Scotland...
, it was extended to John o' GroatsJohn o' GroatsJohn o' Groats is a village in the Highland council area of Scotland. Part of the county of Caithness, John o' Groats is popular with tourists because it is usually regarded as the most northerly settlement of mainland Great Britain, although this is not a claim made by the inhabitants...
via WickWick, HighlandWick is an estuary town and a royal burgh in the north of the Highland council area of Scotland. Historically, it is one of two burghs within the county of Caithness, of which Wick was the county town. The town straddles the River Wick and extends along both sides of Wick Bay...
on 16 May 1935, and later cut back at the southern end because of the construction of the main runway at Edinburgh AirportEdinburgh AirportEdinburgh Airport is located at Turnhouse in the City of Edinburgh, Scotland, and was the busiest airport in Scotland in 2010, handling just under 8.6 million passengers in that year. It was also the sixth busiest airport in the UK by passengers and the fifth busiest by aircraft movements...
on top of it. On 1 April 1997, it was diverted to Thurso at the northern end).
While the road numbering system in Scotland centres on Edinburgh, arguably the true "hub" for its road network itself is Broxden Junction
Broxden Junction
Broxden Junction is one of the busier and more important road junctions in Scotland. It is located on the outskirts of Perth. The roundabout is an important hub of the Scottish road network, a major junction on the A9 north-south route, and the UK's northernmost motorway junction...
in Perth
Perth, Scotland
Perth is a town and former city and royal burgh in central Scotland. Located on the banks of the River Tay, it is the administrative centre of Perth and Kinross council area and the historic county town of Perthshire...
.
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 is the next, 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
A127 road
The A127, also known as the Southend Arterial Road, is one of the trunk roads in England linking London with Southend-on-Sea, the other being the A13. It is a dual carriageway for its entire length, rare on a trunk road since the only others are the A14 and the A282, and is known as the Southend...
, A1079
A1079 road
The A1079 is a major road in northern England. It links the cities of York and Kingston upon Hull, both in Yorkshire.-Route:The road begins in central York, heading east initially as Lawrence Street and then Hull Road. After it meets the A64 at a grade separated roundabout and gains primary status...
and A414
A414 road
The A414 is a major road in England. It runs from the A41 at a junction west of Hemel Hempstead in Hertfordshire, through the town to junction 8 of the M1 motorway at Buncefield, and running parallel to the M1 until junction 7, heading south of St Albans, east through Hatfield, Hertford, then...
. New routes have also been allocated 3 or 4 digit numbers, for example the Edinburgh City Bypass is the A720.
Trunk roads and primary routes
Some A roads are designated trunk roads, which determines whether central or local government has responsibility for them. A more recent classification is that of primary routes, 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. These sections retain the same number but are suffixed with (M), for example the A1(M) and A404(M)A404(M) motorway
The A404 is a motorway in Berkshire, England and can be referred to as the Maidenhead West Bypass. It joins the M4 with the A404 dual carriageway to High Wycombe, Marlow and the M40...
. 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), A329(M)
A329(M) motorway
The A329 is a motorway in Berkshire, England. It is 4 miles long and runs from the north of Bracknell to the south east of Reading.-Route:...
, A38(M) and A48(M)
A48(M) motorway
The A48 is a motorway in Wales between Cardiff and Newport. It is a spur off the M4 into eastern Cardiff. It is long and is a 2-lane motorway throughout its length. At St Mellons it runs continuously into a further of the dual-carriageway A48, which also features hard shoulders.It opened in...
.
Other classifications
B roads are numbered local routes, 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 LondonLondon
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
area are former A roads which have been downgraded owing to new road construction; others may link smaller settlements to A roads.
Lists of B roads
- Zone 1 B roadsB roads in Zone 1 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.-Zone 1 :-Zone 1 :...
- Zone 2 B roadsB roads in Zone 2 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.- Zone 2 :- Zone 2 :-Notes:...
- Zone 3 B roadsB roads in Zone 3 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.-B300 to B399:-B3000 - B3099:-B3100 - B3199:-B3200 - B3299:...
- Zone 4 B roadsB roads in Zone 4 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.-3 digits:-4 digits :-4 digits :-4 digits :...
- Zone 5 B roadsB roads in Zone 5 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.-Zone 5 :-Zone 5 :...
- Zone 6 B roadsB roads in Zone 6 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.-Zone 6 :-Zone 6 :...
- Zone 7 B roadsB roads in Zone 7 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.-Zone 7 :-Zone 7 :...
- Zone 8 B roadsB roads in Zone 8 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.-Zone 8 :-Zone 8 :...
- Zone 9 B roadsB roads in Zone 9 of the Great Britain numbering schemeB roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.-Zone 9 :-Zone 9 :...
Minor roads
Roads and lanes with yet lower traffic densities are designated C, D and U (Unclassified) roads, but while these are numbered, in general this is done purely for the benefit of the local authorities who are responsible for maintaining them, and the numbering is arbitrary and does not, or should not, appear on any public signage. Some exceptions to this are known, however. These other classified roads, however, are taken into account when planning officersTown and country planning in the United Kingdom
Town and Country Planning is the land use planning system governments use to balance economic development and environmental quality. Each country of the United Kingdom has its own planning system that is responsible for town and country planning devolved to the Northern Ireland Assembly, the...
deal with certain planning applications
Planning permission
Planning permission or planning consent is the permission required in the United Kingdom in order to be allowed to build on land, or change the use of land or buildings. Within the UK the occupier of any land or building will need title to that land or building , but will also need "planning...
, including the creation of a new vehicular access onto a highway.
Ancient roads
Some ancient routes, such as Roman roads, travel for great distances and have a single modern number for the majority of their length (e.g. the A5 for the Roman road Watling StreetWatling Street
Watling Street is the name given to an ancient trackway in England and Wales that was first used by the Britons mainly between the modern cities of Canterbury and St Albans. The Romans later paved the route, part of which is identified on the Antonine Itinerary as Iter III: "Item a Londinio ad...
). Others, such as the pre-Roman Icknield Way
Icknield Way
The Icknield Way is an ancient trackway in southern England. It follows the chalk escarpment that includes the Berkshire Downs and Chiltern Hills.-Background:...
and the Roman Fosse Way
Fosse Way
The Fosse Way was a Roman road in England that linked Exeter in South West England to Lincoln in Lincolnshire, via Ilchester , Bath , Cirencester and Leicester .It joined Akeman Street and Ermin Way at Cirencester, crossed Watling Street at Venonis south...
are nowadays rather patchy and where a modern road exists, are numbered according to the local scheme.