A short spur northwest bound and southeast bound linking St Albans to the M1 near Hemel Hempstead. After 50 years as a motorway spur, it was downgraded to the A414 in 2009 due to widening of the M1 between the M25 and Luton.
The designation for the Ringway 2 upgrade of the A406 (North Circular Road) and A205 (South Circular Road). Only the section between junction 4 of the M11 and Redbridge Roundabout was built to motorway standard and was initially signed as M11 because the section built, at the time, only led to and from the M11. When the route was extended to Beckton, this section of M11 was redesignated as the A406 (North Circular Road).[3]
The London West Cross Route, a spur from the London Westway (A40(M)) and the only part of the western section of the London Motorway Box to be built; downgraded to the A3220 in 2000.[4]
A36(M)
Claimed number for the spur at M27 J2. Initially part of the M27 until the Totton Western Bypass opened after which it was downgraded to an extension of the A36.[5] The A36(M) designation was never used; the route was simply named as a spur of the M27.
The northern third of the A329(M) from Winnersh to Reading, now the A3290. Downgraded in the early 1990s to permit Reading council to dedicate one lane for buses.
The southern part (single carriageway link to the B6254) is now the B6601. Downgraded in 2020 to enable access to adjacent development.[8] The remainder of the route was downgraded to the A6070 in 2023.[9]
Formerly the longest single-carriageway motorway spur in the United Kingdom from the M60 north of Sale towards Carrington. Downgraded to a spur of the A6144 in 2006.
Northern and western sections of Ringway 3; completed sections are now part of the M25.
M52
Planned as a Liverpool-to-Manchester motorway; nearly all of it opened as part of the M62 cross-country route, and a short section as the M64 (later M602) in Manchester.[10]
Originally planned to be the western loop around Manchester and Salford; became part of the M63 before the western extension of the M62 was opened; now the M60 J7-J13.[11]
Manchester South Orbital; merged with parts of the M62 and M66 in 1999 to form the new M60Manchester orbital motorway.
M64
Eccles Bypass, formerly part of the M52; it was not considered important enough to carry a two-digit number (and it had not yet opened) and was redesignated as M602.[12]
Gildersome to Leeds Motorway; not considered important enough (and it had not yet opened) to carry a two-digit number, it was redesignated as M621.[13]
M68
Allocated to the southern and eastern sections of the Manchester Outer Ring Road. The eastern section became a portion of the M66 when it opened north of the M62 in the early 1970s and was renumbered to M60 J18-19 in 1998[14] while the southern section was eventually dropped altogether by 2010.
M85
Renumbered to M90 J10-11 in 1994. Previously the M90 carried on along the spur into Perth, leaving the main route ahead as the M85.[15]
M531
Ellesmere Port Motorway; was the A5032 before 1975. Now the M53 J5-10.[16]
Central Motorway East; became the A6127(M) when the A1 was rerouted to run through the Tyne Tunnel. Now the A167(M).[17]
A2(M)
Provisional number for the Medway Motor Road, a bypass of Chatham, Gillingham and Rochester. Changed to M2 as a result of an article in the 15 December 1959 edition of The Daily Telegraph.[18]
A4(M)
Maidenhead Bypass; became a portion of the M4 and later part of the A423(M). Now the A404(M). A small section was abandoned.[19]
A5(M)
Provisional number for the Wellington Bypass, redesignated as the M54 before construction was complete.[20]
Provisional number for the Renfrew Bypass, now part of the M8.[21]
A14(M)
Secretive (unsigned) motorway linking the A14 and A1(M) near Huntingdon. Documents referred the route as A14(M) or A604(M). Became a part of A1(M) when the A14(M) designation was moved to the Huntingdon-Cambridge section of the A14.[22]
Provisional number for the High Wycombe and Beaconsfield bypasses. The Beaconsfield bypass was changed to M40 before it opened. It is not clear when the High Wycombe bypass was renumbered, but it too is now the M40.
The Adwick-le-Street to M62 stretch of the A1 is under consideration for upgrade to motorway standard, meaning the A1 between Blyth, south of Doncaster, to Birtley near Gateshead, would all be part of the same A1(M) stretch of motorway.
In addition, the proposal to put a tunnel under the River Thames to the east of Dartford Crossing and the revived Birmingham Western Orbital plans are both described as motorways.[31][32]
Unbuilt motorways
There have been many plans for motorways in the UK that have not been built. Below is a list of plans that were not built (not exhaustive):
M1 Sterling Corner Link, linking the A1 at Sterling Corner to the M1.[33]
M12 in 3 forms (although a small part was built and is not used - a stub sliproad):[34]
M14, reserved as the long-term designation for the western side of Ringway 1, intended to replace the temporary M41 number. It is unknown if it was to apply to all of Ringway 1 as an M1x number would have been out-of-zone for the West Cross Route in isolation.
M17 Castle Donington bypass, a short spur off the M1. Now part of the A42.
M19, M1 to A1 in Yorkshire. Functionally equivalent to the M62 between junction 29 and 32A, but located further to the north, and without the eastern extension to Hull.[36] Now part of the M62.
M30, a proposed renumbering of the M3 once it was extended from Basingstoke to Southampton, but it never happened and the route remains the M3.[37]
M31, a bypass of the busiest section of the M25, cutting the corner for traffic from the west.[38] Partially built as the A329(M) and A3290.
M56-M62 Link, from the M56 to the M62, cutting the corner in Cheshire. Cancelled in 1993.[39]
M58, very early proposed number for the proposed Preston Southern Bypass.
M58 Mid-Lancashire Motorway, from west of Wigan to west of Bolton and the M61; cancelled in 1969. In the mid-1970s the M58 was reinstated, but as a two-lane dual carriageway and was cancelled again in 1986. In 1989, it was re-instated a second time, but was rerouted to end at the A58 instead of the M61 in 1993 and cancelled yet again in 1996. Wigan MBC picked up the M58 in the late 1990s, but only the western end was dual carriageway and the rest was downgraded to single carriageway. In 2007 the M58 was cancelled for good.[40]
M59, M58 J2 to south of Preston. Gradually trimmed back and eventually cancelled, partially due to widening of the M6.[41]
M60, a bypass of Altrincham and Sale, running from the M56 to Manchester. One section built as the A6144(M),[42] and the section between M6 and M56 was built as an all-purpose dual carriageway bypass of the A556 (this section was planned as A556(M)).[43]
M62 Relief Road, intended to relieve traffic on the existing M62, running alongside the M62 to the north and west of Salford and Manchester. Cancelled in 1995.[44]
M64, between the M6 south of Stoke-on-Trent and the M1 near Derby. Cancelled in 1976 to save costs, but the central section was built as an upgrade of the A50.
M81, proposed number for the Maryhill Motorway and Trossachs Motorway, bypassing the A81 between Central Glasgow and Milngavie.
M82, proposed number for the North Link Motorway and Lomond Motorway.
M83, proposed number for the South Link Motorway and East Link Motorway, providing a south bypass of Glasgow via Rutherglen.
M100, number reserved by the Department for Transport for a completed A1(M) between London and Tyneside.
M111 (or M110), number reserved for the rump section of the M1 if the route was extended west to the A1. Because the M1 was extended east, the renumbering never happened.
M272 Portswood Link, initially cancelled in the mid-1970s, but was reinstated in the 1980s as M27. Built as the A335 in 1989.
M274, proposed number for the M27 spur / M275 mainline from the M27 northwards at Port Solent Interchange. Number never assigned or used; now part of the M27/M275.
A6(M) (or M66 extension), which would have formed an eastern bypass for Stockport.[51] As of March 2006, this is still under the planning stage as part of the SEMMMS (south east Manchester multi modal study) project (though not as motorway).
A11(M), original number for the M11.
A14(M), number for the planned upgrade of the A14 between Cambridge and Huntingdon. The proposal was dropped in 2019 to allow the road to be opened sooner, and it opened as the A14 as a "best in Class A road" instead.[52][53]
A34(M), a motorway standard bypass of Handforth, Wilmslow and Alderley Edge. The route later opened as non-motorway A34 bypasses.
A48(M) Llantrisant Radial, branching off the A48 and running west out of Cardiff towards M4 J33. Cancelled in 1971 in favor of construction of the M4 north of Cardiff.[54]
A59(M) Ormskirk Bypass, planned bypass of Ormskirk, Burscough and Rufford. Became part of the planned M59 in 1963.[55]
A556(M), which would have cut the corner between the M6 and M56 near Warrington; originally part of the planned M60. Cancelled in 2003,[57] but completed in 2017 as an all-purpose dual carriageway bypass of the A556.
A695(M) Shields Road Motorway, running from the A167(M) to A187 in Newcastle-upon-Tyne, cancelled in 1975. Later partially built as a bypass of the A193.
A Ring, planned ring around Central London. Cancelled in 1950 as too expensive.[58]
Belmont Link Motorway, linking the M6 to the A675 south of Higher Walton. It was proposed as part of the 1949 Road Plan for Lancashire, and its line confirmed by the Ministry in 1960, but no construction contracts were granted.[59]
Bilston Link Motorway, linking M6 J10 to the A4123.[60]
Blackpole - Whittington Motorway, proposed motorway in Worcester serving new development east of the city. The portion north of the B4636 is now the B4638.
Central Motorway East Bypass, bypassing the Central Motorway East and the Tyne Bridge. Cancelled as it was ahead of its time, although some stub sliproads were built in case the motorway was built later.
Central Motorway West, running from New Redheugh Bridge to Town Moor Interchange, cancelled in 1975. One section completed as the B1318 and another section became a surface-level road.
Central Spine Motorway, running north-south via Worcester.
Claremont Road Motorway, essentially an extension of the Central Motorway East to relieve traffic on Claremont Road. Built as the A167 and A167(M).
Coventry North-South Motorway, running north to south through Coventry. All of the route (except for one section) built as the A444.[62]
Cublington Airport Motorway, planned motorway to serve Cublington Airport.
Denham Spur, cutting the corner between the M40 and Ringway 3 to the north
Derby Urban Motorway, proposed link from the Derby Inner Ring Road (A601) to the then-A6 (now A5194) at London Road
Droitwich - Leicester Motorway, a proposed pre-war motorway, one of two crossing the Midlands between the M1 and the Bristol-Birmingham-Preston motorway corridor (this one was southwest-northeast, the other was southeast-northwest). It eventually morphed into the M42 and M69 schemes. The route was numbered as M4 and M46.
East Coast Motorway, unofficial proposal in early 1991 for a motorway running along the eastern side of England.
East Cross Route, from Hackney Wick to Kidbrooke Park as the eastern section of Ringway 1. Now the A12 and A102.
Eastern Motorway (Portsmouth), planned motorway running from the M27 to Portsmouth, complementing the M275.
EuroRoute, rival proposal to the Channel Tunnel.[64]
Friars Goose Crossing, planned crossing of the River Tyne, linking Newcastle to the south.[65]
Furness Link, running from the M6 at Carnforth to Grange-over-Sands. Now the A601(M).[66]
Glasgow Inner Ring Road, planned ring road around Glasgow city center. Partially built as M8 J15-J20.[67]
Hamilton-Cumbernauld Motorway
Hook Road, connecting Cardiff to the northern suburbs at the missing M4 J31. Cancelled in 1972 due to immense opposition.
Johnstone Motorway
Kendal Link
Liverpool Inner Motorway
London Oxford Airport Motorway
Malvern Radial Motorway, proposed motorway in Worcester, running west of the city center and bypassing the A44 through St Johns and ending at the A4103 at Rushwick. A dual carriageway link would continue on to the A449 at Powick, taking traffic to Malvern.
Manchester Inner Ring Road, planned ring road around Manchester city center.
Morecambe Link Motorway, an east-west bypass of Lancaster
Newport Southern Bypass, planned bypass of M4 to the south of Newport. Planned to be tolled, it was designated as M4 Toll. It was scrapped in 2009 due to increased costs of building the road. Although given full approval in 2014, it was cancelled again in 2019.
North Cross Route, northern section of Ringway 1 (innermost ring of London). Only a small section was constructed at the eastern end, and no evidence has been found that it had a motorway number.
Northern and Western Motorway, a 1923 motorway plan. A core section would run from the A45 to the east of Coventry, around southern Birmingham and the west of the Black Country and Wolverhampton north to Manchester and Salford and ending at the A57. A southern section would branch off at Coventry and head to London, paralleling the A41 and along the present A413 to the end of the proposed Western Avenue (A403) at the Denham Roundabout. A northern branch was planned from Altrincham to Liverpool and even a branch of this branch, from St Helens to Oldham, passing north of Manchester. Government disinterest and the power of the railways killed off the plan.
Paisley - Hamilton Motorway
Princess Parkway Motorway, heading south from Manchester. Part of route now the A5103 north of M56 J3.
Ringway 2, planned upgrades of the A205 and A406 and a replacement for the Woolrich Ferry. One section, between the M11 and A13, would have been designated as the M15. Initially known as the "C Ring".
Ringway 3, proposed third ring around London, running along the north of the M25 from J23 to J3 via the Dartford Crossing. The section from South Mimms to Potters Bar was numbered as M16, but it is unknown whether the number would have applied to the entire route. Now part of the M25.
Ringway 4, proposed fourth ring around London, running along the M26 and M25 from J5 to the spur off J19. The M25 number was planned for the motorway.
Sheffield Spur Motorway, a section of M1 left over when it was rerouted to end at Doncaster. It was numbered M11 or M58 (depending on numbering scheme). This spur was extended towards Leeds and became the M1 again, while the rump bit between Thurcroft and Doncaster became the M18.
South Bristol Spur, running from Ashton Gate to M5 J20. Portion of route now the A370.
South Cross Route, the southern section of Ringway 1. Never built.
Strensham – Solihull motorway, a link between the M50 and M42; it was routed via Evesham but this was cancelled as it ran through farmland, and so it was changed to ran through Redditch instead. In the earliest stages of planning, a route that would have linked it with the M69 was considered.[68]
Thames Gateway Airport Access Road, linking M2 J1 at Strood to the proposed Thames Gateway Airport.
Townhill Link Motorway, from M27 J6 (also not built) into Southampton via Townhill and ending at Mousehole Roundabout north of Bitterne. Unofficially numbered as M273.
Trafford Park Motorway, sort spur with an intermediate junction that was part of SELNEC plans.
Warndon Radial Motorway, proposed motorway in Worcester running from the Central Spine Motorway to the Blackpole-Whittington Motorway.
Western Orbital Motorway - M6 north of M54/M6 junction to M5 near Bromsgrove. Planned to relieve congestion in the West Midlands, this would have diverted traffic heading north west to south west away from the heavily congested M6 south of Walsall. A spur was planned to link to the A449 north of Wombourne. This proposal has been around since construction of the M42 started. The idea has not been completely abandoned but is more likely to be built as an all-purpose road rather than a motorway.
Weston Spur, running from the M5 to Weston-super-Mare
The following motorways were planned, but never built:
M4, from Belfast south to Carryduff, where the roads to Newcastle and Downpatrick split. Bypasses the A24 Ormeau Road.[72]
M6, branching off the M5 and heading north to Larne.[72]
M7, bypassing the A20 between central Belfast and Dundonald, with plans to extend it to Newtownards. Ran along an old railway line.[72]
M8 Belfast Southern Link, ran along the Lagan Valley from the M1 at Belfast to the M4 at Stranmillis, intended to distribute traffic heading from Lisburn to Belfast, taking traffic heading to North Down and East Belfast off the M1 before M11 traffic from Newry and northern Lisburn merged in. Cancelled in 1969 due to poor traffic estimates and the removal of a section of the M4 north of Stranmillis.[72]
M11, from the M1 going through Lisburn and then crossing the M1 again and ending at Newry. Intended to be the main route for Dublin, bypassing the A1. Not seen as important, being one of the lowest priorities for construction and relied on Craigavon plans for a new large city being built. Cancelled in 1969; the A1 was upgraded instead.[72]
M21 Belfast Airport Motorway, number reserved for a motorway to Belfast Airport.
^ abcUnder its charter, motorways are excluded from the remit of Transport for London. These routes had their motorway status removed to allow TfL control over them.
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