The Great Britain road numbering scheme is a numbering system used to classify and identify all major roads in Great Britain.
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. Similar systems are used in Northern Ireland (see Roads in Ireland), the Isle of Man (see Roads in the Isle of Man) and Jersey, Channel Islands. All of these numbering schemes use identical basic conventions and road-sign designs.

Important radial roads in England and Wales
Similarly, in Scotland, important roads radiating from Edinburgh have single digit numbers, thus:
While the road numbering system in Scotland centres on Edinburgh, arguably the true "hub" for its road network itself is Broxden Junction in Perth.

A7 Edinburgh to Carlisle
A8 Edinburgh to Greenock
A9 Falkirk to Thurso (Originally Edinburgh to Inverness, it was extended to John o' Groats in the 1930s, and later cut back at the southern end because of the construction of the main runway at Edinburgh Airport on top of it. More recently, it was diverted to Thurso at the northern end.) Important radial roads in Scotland
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. In Scotland the same scheme is centred on Edinburgh. In both cases the main single-digit roads (largely) define the zone boundaries, with the exception of the Zones 1 and 2.
Zone 1: North of the Thames, east of the A1 Zone 2: South of the Thames, east of the A3 Zone 3: North/West of the A3, south of the A4 Zone 4: North of the A4, south/west of the A5 Zone 5: North/East of the A5, west of the A6, south of the Solway Firth/Eden Estuary Zone 6: East of the A6 and A7, west of the A1 Zone 7: North of the Solway Firth/Eden Estuary, west of the A7, south of the A8 Zone 8: North of the A8, west of the A9 Zone 9: North of the A8, east of the A9 Motorways in England and Wales use a similar zoning system, based on the single-digit motorways. Motorways in Scotland are numbered differently.
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, a trunk road running from Bodmin to Mansfield starts in Zone 3, and is therefore numbered with a A3x number, even though it passes through Zones 4 and 5 to end in Zone 6. Additionally, the A1 in Newcastle upon Tyne has moved twice. Originally along the Great North Road, it then moved to the Tyne Tunnel, 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.
To view a list of roads where this does not apply, see Anomalously numbered roads in Great Britain.

Zoning system
These radials are supplemented by two-digit codes which are routes that are 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:
Note on numbering: These roads have been numbered either outwards from or clockwise around their respective hubs, depending on their alignment.

A10 London to King's Lynn (known as the Great Cambridge Road or the Old North Road)
A11 London to Norwich
A12 London to Great Yarmouth
A13 London to Shoeburyness
A14 M1/M6 Catthorpe junction near Rugby to Felixstowe (Originally Royston to Huntingdon)
A15 Peterborough to Hull
A16 Stamford to Grimsby
A17 Newark to King's Lynn
A18 Doncaster to Ludborough
A19 Doncaster to Seaton Burn
A20 London to Dover
A21 London to Hastings
A22 London to Eastbourne
A23 London to Brighton
A24 London to Worthing
A25 Wrotham Heath to Guildford
A26 Maidstone to Newhaven
A27 Pevensey to Whiteparish
A28 Margate to Hastings
A29 Beare Green to Bognor Regis
A30 London to Land's End
A31 Guildford to Bere Regis
A32 Alton to Gosport
A33 Southampton to Reading
A34 Winchester to Salford
A35 Southampton to Honiton
A36 Southampton to Bath
A37 Dorchester to Bristol
A38 Bodmin to Mansfield
A39 Bath to Falmouth
A40 London to Fishguard
A41 London to Birkenhead
A42 Appleby Magna (M42) to Kegworth(M1) (Originally Reading to Birmingham: taken over by A34)
A43 Cherwell Valley to Stamford (formerly Oxford to Market Deeping)
A44 Oxford to Aberystwyth
A45 Birmingham to Thrapston (Originally to Felixstowe, but eastern section taken over by A14)
A46 Bath to Cleethorpes
A47 Birmingham to Great Yarmouth
A48 Highnam to Carmarthen
A49 Ross-on-Wye to Bamber Bridge near Preston
A50 Leicester to M1 Junction 22 and Kegworth (M1 Junction 24) to Warrington (formerly Northampton to Warrington)
A51 Kingsbury to Chester
A52 Newcastle-under-Lyme to Mablethorpe
A53 Shrewsbury to Buxton
A54 Chester to Buxton
A55 Holyhead to Chester (The North Wales Expressway)
A56 Chester to Broughton (A59)
A57 Liverpool to Lincoln
A58 Prescot to Wetherby
A59 Liverpool to York
A60 Loughborough to Doncaster
A61 Derby to Thirsk
A62 Manchester to Leeds
A63 Leeds to Hull
A64 Leeds to Scarborough
A65 Leeds to Kendal
A66 Workington to Grangetown
A67 Bowes (A66) to Crathorne (A19)
A68 Darlington to Edinburgh
A69 Carlisle to Blaydon
A70 Edinburgh to Ayr
A71 Edinburgh to Irvine
A72 Galashiels to Hamilton
A73 Abington to Cumbernauld
A74 Carlisle to Glasgow
A75 Gretna to Stranraer
A76 Dumfries to Kilmarnock
A77 Glasgow to Portpatrick
A78 Prestwick to Greenock
A79 Prestwick to Doonholm
A80 Glasgow to Bonnybridge
A81 Glasgow to Callander
A82 Glasgow to Inverness
A83 Campbeltown to Tarbet
A84 Stirling to Lochearnhead
A85 Oban to Dundee
A86 Spean Bridge to Kingussie
A87 Invergarry to Uig
A88 Larbert to Stenhousemuir (Originally what is now the A9 past Inverness: this explains the rarity of A9xxx numbers in the Highlands)
A89 Newbridge to Glasgow
A90 Edinburgh to Fraserburgh
A91 Bannockburn to St Andrews
A92 Dunfermline to Stonehaven
A93 Perth to Aberdeen
A94 Perth to Forfar
A95 Aviemore to Meld
A96 Inverness to Aberdeen
A97 Dinnet to Banff
A98 Fochabers to Fraserburgh
A99 Latheron to John o' Groats Two-digit "A" roads
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. Most roads built or reclassified since road numbers were introduced in 1919 have four-digit numbers. Knowing the number of the road you are on will give you a rough idea of where you are geographically once the system is understood. Below is a rough guide to the numbering series which apply to the various areas of the Great British mainland:
Some of the most important 3-digit "A" roads are:
A small number of 4-digit A roads have grown in importance since the numbers were allocated:

10 and 100 series numbers: Greater London, Essex, Cambridgeshire, East Anglia, Lincolnshire, parts of Yorkshire, Cleveland, Tyne and Wear, Northumbria, and on up to Edinburgh.
20 and 200-series numbers: Surrey, Sussex and Kent
30 and 300-series numbers: Hampshire, the Isle of Wight, Dorset and South West England
40 and 400-series numbers: Central England and south and Mid Wales
50 and 500-series numbers: North Wales, North Midlands, Cheshire, Cumbria and Lancashire
60 and 600-series numbers: North-East England, Yorkshire and South East Scotland
70 and 700-series numbers: South West and Central Scotland
80 and 800-series numbers: North West Scotland and the Western Isles
90 and 900-series numbers: North East Scotland, Orkney and Shetland
A127 Romford to Southend-on-Sea (the Southend Arterial Road or New Southend Road)
A205 Woolwich to Chiswick (South Circular Road)
A259 Folkestone to Havant. Forms part of the South Coast Trunk Road between the A2070 and A27.
A272 Poundford to A30 near Andover
A303 Basingstoke to Honiton (relieves traffic from the A30)
A361 Ilfracombe to Rugby (the longest 3-digit road)
A403 Avonmouth to Aust
A406 Chiswick to Beckton (North Circular Road)
A414 Hemel Hempstead to Maldon
A465 Bromyard to Neath (Head of the Valleys Road)
A470 Cardiff to Llandudno
A483 Swansea to Chester
A487 Haverfordwest to Bangor
A580 Liverpool to Manchester (East Lancs Road)
A538 Altrincham to Wilmslow (Hale Road becoming Wilmslow Road)
A689 Carlisle to Hartlepool
A720 Edinburgh City Bypass
A1079 Hull to York
A2070 Ashford to Romney Marsh in Kent. Now part of the South Coast Trunk Road. Other "A" roads
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 A-road route. These sections retain the "A" road designation, but are suffixed (M). Examples include:
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. Examples include:

A1(M)
A404(M)
A3(M)
A308(M)
A329(M)
A48(M) Motorway sections of "A" roads
"B" roads are numbered local routes, which have lower traffic densities than the main trunk roads, or A road. They are typically short, not usually more than 15 miles. The 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 area are former A roads which have been downgraded owing to new road construction; others may link smaller settlements to A roads.

"B" 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. [1] These other classified roads, however, are taken into account when planning officers deal with certain planning applications.

"C", "D" and "U" roads
Main article: List of motorways in the United Kingdom
The first motorway in Britain was the Preston Bypass, opened in December 1958. This is now a section of M6, plus the M55 to junction 1. The M1, M10 and M45 opened together in 1959.
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 conterminous with that of the A-road network, though based on the same principle of zones.
The most important single-digit motorways were numbered to (loosely) match the existing main roads which the motorway follows or was intended to relieve traffic from. The level of correlation differs; the M4 motorway stays very true to the line of the A4 road throughout England, whereas the M1 motorway meanders a path not too close to the A1 road, although generally north-south like its predecessor.
A very obvious exception to this rule is the M5, which closely follows the A38. It was numbered uniquely as it was already known that the A5 road needed no such motorway bypass as this was already the job of the M1/M6.
The single-digit motorways mark out zones or cones, the concept analogous with that of the A-road network. However, due to the difference in position of the A5 vs. the M5, the actual position of these zones varies greatly, especially in the Midlands and South West England.
Shorter motorways typically take their numbers from a parent motorway in violation 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. The latter two might be explained by the original plan for the M3 motorway, which was due to head towards Exeter, rather than Southampton as it does now. The original committee which set up the motorway zones chose the boundary of zones 2 and 3 to be the projected line of the M3 towards Exeter, although it's not currently known whether this is still the case.
This numbering system was devised in 1958-9 by the then Ministry of Transport and Civil Aviation, and applied only in England and Wales. In Scotland, where roads were the responsibility of the Scottish Office, the decision was taken to adopt the numbering originally proposed, in that 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, the short M85 became part of the M90.

Motorways
Fictional numbers are assigned for use on TV and film; such a number that is involved with a serious fictional accident is blacklisted for five years from actual use.

Ancient roads



UK topics