Motorways in the United Kingdom
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 M1 the zones were defined for Zones 1 to 4 based on the proposed M2, M3 and M4 motorways. The M5 and M6 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.
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. This numbering system was devised in 1958-9 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 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, the short M85 became part of the M90.
- Main article: Great Britain road numbering scheme
In England and Wales, the numbers of major motorways followed a numbering system separate to 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 motorways. The M5 and M6 numbers were reserved for the other two planned long-distance motorways. The Preston Bypass, the UK's first motorway, 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. Certain portions or bypasses of A-roads may be designated as motorways, the name of these portions being given the suffix "(M)". An example is the A1(M).
In Scotland, where the Scottish Office rather than the Ministry of Transport and Civil Aviation had the decision, there is no zonal pattern, but rather the A-road rule is strictly enforced. It was decided to reserve the numbers 7, 8 and 9 for Scotland. The M8 follows the route of the A8, and the A90 became part of the M90 when the A90 was re-routed along the path of the A85.
Counties with one or more sections of motorway are: Ayrshire, Bedfordshire, Berkshire, Buckinghamshire, Cambridgeshire, Carmarthenshire, Cheshire, Cumberland, Derbyshire, Devon, Dumfriesshire, Dunbartonshire, Durham, Essex, Fife, Glamorgan, Gloucestershire, Hampshire, Herefordshire, Hertfordshire, Huntingdonshire, Kent, Kinross-shire, Lanarkshire, Lancashire, Leicestershire, Middlesex, Midlothian, Monmouthshire, Northamptonshire, Northumberland (short isolated section of urban motorway in Newcastle), Nottinghamshire, Oxfordshire, Perthshire, Renfrewshire, Shropshire, Somerset, Staffordshire, Stirlingshire, Surrey, Sussex, Warwickshire, West Lothian, Westmorland, Wiltshire, Worcestershire and Yorkshire.
Counties with no sections of motorway are: Aberdeenshire, Anglesey, Angus, Argyllshire, Banffshire, Berwickshire, Brecknockshire, Buteshire, Caernarfonshire, Caithness, Cardiganshire, Clackmannanshire, Cornwall, Cromartyshire, Denbighshire, Dorset, East Lothian, Flintshire, Inverness-shire, Kincardineshire, Kirkcudbrightshire, Lincolnshire, Merionethshire, Montgomeryshire, Morayshire, Nairnshire, Norfolk, Orkney, Peeblesshire, Pembrokeshire, Radnorshire, Ross-shire, Roxburghshire, Rutland, Selkirkshire, Shetland, Suffolk, Sutherland and Wigtownshire.
In Northern Ireland a distinct numbering system is used, which is separate from the rest of the United Kingdom, though the classification of roads along the lines of A, B and C is universal throughout the UK and the Isle of Man. According to a written answer to a parliamentary question to the Northern Ireland Minister for Regional Development, there is no known reason as to how Northern Ireland's road numbering system was devised. However motorways, as in the rest of the UK, are numbered M, with the two major motorways coming from Belfast being numbered M1 and M2. The M12 is a short spur of the M1 with the M22 being a short continuation (originally intended to be a spur) of the M2. There are two other motorways, the short M3, the M5 and a motorway section of the A8 road, known as the A8(M).
- "How the Motorways were numbered". Ministry of Transport memorandum. Pathetic Motorways. November 1961. http://pathetic.org.uk/features/numbering/part4.shtml. Retrieved 2007-12-28. "Mr Usborne explained that his proposal followed the principle of the sector system on which trunk and classified roads were already numbered, although the sectors themselves, which were six in number, were somewhat different."
- Wykes, C. H. (1959-07-07). "How the Motorways were Numbered". Ministry of Transport Memorandum. Pathetic Motorways. http://pathetic.org.uk/features/numbering/part2.shtml. Retrieved 2007-12-28. "The result of applying such a system to current plans would be the appropriate numbering of the London - Yorkshire Motorway as M.1, with provision for extension still further north as required. M.2 would be reserved for any possible Channel Ports Motorway, the Medway Towns Bypass meanwhile becoming A.2(M) and the Maidstone Bypass A.20(M). M3 would be reserved for a motorway in the direction of Portsmouth - Southampton, starting with the Exeter Radial. M.4 would be applied to the South Wales Radial. The remaining single figure numbers would not be required for radials and could therefore, continuing clockwise, be applied to the Bristol - Birmingham Motorway - M.5 and the Penrith - Birmingham plus Dunchurch Bypass - M.6. The Preston Bypass was numbered M.6 in advance and although under these proposals it should initially have been A.6(M), I see no reason to make any change from M.6 pending the ultimate completion of the whole route."
- "Numbers for motorways". 25 January 2015. http://www.cbrd.co.uk/articles/road-numbers/motorways.shtml.
- Payne, B. A. (1959-07-10). "How the Motorways were Numbered". Ministry of Transport Memorandum. Pathetic Motorways. http://pathetic.org.uk/features/numbering/part2.shtml. Retrieved 2007-12-28. "1. The numbers 7, 8 and 9 which were used in Scotland should be reserved for the use of Scottish Motorways."
- "How the Motorways Were Numbered". Ministry of Transport. November 1961. http://pathetic.org.uk/features/numbering/part4.shtml. Retrieved 28 December 2007. "Mr Usborne explained that his proposal followed the principle of the sector system on which trunk and classified roads were already numbered, although the sectors themselves, which were six in number, were somewhat different."
- Wykes, C. H. (30 September 1959). "How the Motorways Were Numbered". Ministry of Transport. http://pathetic.org.uk/features/numbering/part2.shtml. Retrieved 28 December 2007. "Where, however, a motorway is merely a by-pass along an existing route such as the Doncaster Bypass along Route A.1, it will not be given a separate M number, but in order to make it clear that it is a motorway and that motorway Regulations apply to it, the letter M will be added in brackets to the existing route-number: e.g. A.1(M) for the Doncaster Bypass. This will preserve the continuity of the route-number of long-distance all-purpose roads. Generally speaking by-passes that are eventually linked to form a continuous motorway will preserve the existing route-number (plus M in brackets) until they are so linked."
- Payne, B. A. (10 July 1959). "How the Motorways Were Numbered". Ministry of Transport. http://pathetic.org.uk/features/numbering/part2.shtml. Retrieved 28 December 2007. "1. The numbers 7, 8 and 9, which were used in Scotland, should be reserved for the use of Scottish Motorways."
- Northern Ireland Assembly Information Office. "The Northern Ireland Assembly". Northern Ireland Assembly. http://www.niassembly.gov.uk/qanda/writtenans/001215.htm. Retrieved 10 August 2009.
|Motorways in the United Kingdom|
Great Britain: M1 • M2 • M3 • M4 • M5 • M6 • M6 Toll • M8 • M9 • M10 • M11 • M18 • M20 • M23 • M25 • M26 • M27 • M32 • M40 • M42 • M45 • M48 • M49 • M50 • M53 • M54 • M55 • M56 • M57 • M58 • M60 • M61 • M62 • M63 • M65 • M66 • M67 • M69 • M73 • M74 • M77 • M80 • M85 • M90 • M180 • M181 • M271 • M275 • M602 • M606 • M621 • M876 • M898 • Sections of A road: A1(M)
Former motorways marked in italics