The following table lists all British roads which are anomalously numbered. Roads in bold lie completely outside of the "correct" zone; all other roads run for some length in the "correct" zones but trespass into zones anticlockwise of this zone.
Road Number |
Location |
Trespassed zone(s)
|
Reason |
M48 |
Gloucestershire, Monmouthshire |
Zone 5 |
This road was formerly the M4 and links up with the A48. |
M49 |
Bristol, Gloucestershire |
Zone 3 |
This motorway lies entirely within zone 3 [1]. The motorway was constructed at the same time as the 2nd Severn Crossing, and it's likely that they used the sequential M48 and M49 for the old M4 and the new motorway respectively. |
M62 |
Merseyside, Greater Manchester/Lancashire (traditionally) |
Zone 5 |
The section from Liverpool to Manchester was planned as M52, but was added to the M62 to make a cross-country route. |
M65 |
Lancashire |
Zone 5 |
The short link to the A582 is out-of-zone |
M271 |
Hampshire |
Zone 3 |
Numbered as a spur of the M27, as opposed to the traditional numbering rules, however M3 to Southampton came after the M271 was built and may not be the zone boundary, which appears to be a straight line from M3 j8 to Exeter in some documentation |
Road Number |
Location |
Trespassed zone(s)
|
Reason |
A14 |
Northamptonshire |
Zone 5 & 6 |
The A14 was chosen as a unique, important number for this crucial cross-country route. |
A31 |
Surrey |
Zone 2 |
A section of the A31 through Guildford was bypassed east by the A3. |
A42 |
Leicestershire |
Zone 5 |
The A42 is numbered as an extension of the M42. |
A51 |
Warwickshire |
Zone 4 |
|
A55 |
Anglesey |
Zone 4 |
The A55 supersedes the A5 through Anglesey. |
A66 |
Cumbria |
Zone 5 |
The A66 was extended westwards beyond the A6 to make it a cross-country route. |
A88 |
Falkirk |
Zone 9 |
Planned to extend westwards to form the A80 to Kincardine Bridge road - this instead became the M876. |
A89 |
Glasgow |
Zone 7 |
The A89 through Glasgow was partly formerly the A8. |
A167 |
Durham |
Zone 6 |
The A167 through Durham was formerly part of the A1. |
A168 |
North Yorkshire |
Zone 6 |
The A168 was formerly part of the A1. |
A177 |
Durham |
Zone 6 |
The A1 was moved east of the A177's start point in Durham City. |
A181 |
Durham |
Zone 6 |
The A1 was moved east of the A181's start point in Durham City. |
A199 |
East Lothian |
Zone 6 |
The A199 was formerly part of the A1. |
A282 |
Thurrock |
Zone 1 |
New road which is important and assigned an A2xx number. Could be A108 or A122, both unused numbers at present. |
A307 |
Surrey |
Zone 2 |
The A307 was formerly part of the A3. |
A320 |
Surrey |
Zone 2 |
As A307. |
A322 |
Surrey |
Zone 2 |
As A307. |
A397 |
Portsmouth |
Zone 2 |
The A397 was formerly part of the A3. |
A404 |
Windsor and Maidenhead |
Zone 3 |
The A404 was formerly part of the A4. |
A412 |
Slough |
Zone 3 |
|
A427 |
Northamptonshire |
Zone 6 |
The A427 previously ran from Coventry to Oundle, and was truncated west of Market Harborough, when the new A14 opened. This section was renumbered as the B4027, A4303 and A4304. An even older alignment (pre-c.1960s) heading south from North Kilworth as far as the A45 is now an unclassified road (formerly B5414) and A4071. |
A505 |
Bedfordshire |
Zone 4 |
The A505 was extended to become a cross-country route. |
A601 |
Derby |
Zone 5 |
Chosen as a unique number for the Derby inner ring road. |
A620 |
Nottinghamshire |
Zone 1 |
The A620 was truncated and left east of the A1. |
A624 |
Chapel-en-le-Frith, Derbyshire |
Zone 5 |
The A624 was formerly part of the A6 for a short stretch in Chapel-en-le-Frith before the Chapel By-pass was built. |
A683 |
Lancashire |
Zone 5 |
The A683 was extended westwards to Heysham docks. |
A720 |
Edinburgh |
Zone 6 |
The A720 bypasses Edinburgh, a numbering hub, making numbering difficult; A720 was chosen for apparent importance. Most important 6-zone numbers were all used. |
A882 |
Highland |
Zone 9 |
The A882 was formerly part of the A9. |
A899 |
West Lothian |
Zone 7 |
The A899 was extended south through Livingston new town, Scotland. |
A949 |
Highland |
Zone 8 |
The A949 was formerly part of the A9. |
A1000 |
Hertfordshire |
Zone 6 |
The A1000 was formerly part of the A1. |
A1057 |
Hertfordshire |
Zone 6 |
As A1000. |
A1068 |
Northumberland |
Zone 6 |
The A1068 was formerly part of the A1. |
A1081 |
Hertfordshire |
Zone 6 |
The A1081 was formerly part of the A6. |
A1246 |
North Yorkshire |
Zone 6 |
The A1246 was formerly part of the A1. |
A3023 |
Hampshire |
Zone 2 |
|
A3100 |
Surrey |
Zone 2 |
The A3100 was formerly part of the A3 (and the A31). |
A3400 |
Warwickshire |
Zone 4 |
The A3400 was formerly part of the A34. |
A4174 |
Bristol |
Zone 3 |
The A4174 is part of the Bristol outer ring road. It was originally entirely in zone 4 but has been extended to the A4 and then south of it. |
A4208 |
London |
Zone 3 |
Truncation of the A4 left the A4208 out-of-zone. |
A4300 |
Northamptonshire |
Zone 5 |
The A4300 was formerly part of the A43. |
A4303 |
Leicestershire |
Zone 5 |
The A4303 was formerly part of the A427. |
A4304 |
Leicestershire |
Zone 5 |
As A4303. |
A4500 |
Northamptonshire |
Zone 5 |
The A4500 was formerly part of the A45. |
A4501 |
Northamptonshire |
Zone 5 |
As A4500. |
A4601 |
Staffordshire |
Zone 5 |
The A4601 was formerly part of the A460. |
A5127 |
Staffordshire |
Zone 4 |
The A5127 was extended south when the A38 bypassed Lichfield. |
A5140 |
Bedfordshire |
Zone 4 |
|
A5153 |
Anglesey |
Zone 4 |
The more-important A55, rather than the A5, is taken to be zone boundary. |
A5154 |
Anglesey |
Zone 4 |
The more-important A55, rather than the A5, is taken to be zone boundary. |
A5223 |
Telford |
Zone 4 |
|
A6004 |
Leicestershire |
Zone 5 |
The A6004 was formerly part of the A6. |
A6010 |
Manchester |
Zone 5 |
The A6010 is part of the Manchester ring road. |
A6143 |
Manchester |
Zone 5 |
|
A6144 |
Trafford |
Zone 5 |
|
A6182 |
Doncaster |
Zone 1 |
The A1 was rerouted leaving the A6182 out-of-zone. |
A8000 |
Edinburgh |
Zone 9 |
The A8000 was truncated with the building of the M9 spur halfway to the Forth Road Bridge. |
Road Number |
Location |
Trespassed zone(s)
|
Reason |
B197 |
Hertfordshire |
Zone 6 |
The B197 was formerly part of the A1 |
B316 |
London |
Zone 4 |
A4 rerouted |
B325 |
London |
Zone 4 |
A4 rerouted |
B455 |
London |
Zone 3 |
|
B470 |
Windsor and Maidenhead |
Zone 3 |
|
B576 |
Northamptonshire |
Zone 6 |
A6 rerouted |
B645 |
Northamptonshire |
Zone 5 |
A6 rerouted |
B855 |
Highland |
Zone 9 |
The A9 was rerouted west of this road, to end at Thurso. |
B876 |
Highland |
Zone 9 |
The A9 was rerouted west of this road, to end at Thurso. |
B1043 |
Cambridgeshire |
Zone 6 |
The B1043 was formerly part of the A1. |
B1164 |
Nottinghamshire |
Zone 6 |
The B1164 was formerly part of the A1. |
B1217 |
Leeds |
Zone 6 |
extended along old A642 when M1 extended |
B1224 |
North Yorkshire |
Zone 6 |
The A1 was re-routed, leaving its start-point out of zone. |
B1284 |
Durham |
Zone 6 |
The A1 was re-routed, leaving its start-point out of zone. |
B3000 |
Surrey |
Zone 2 |
A3 rerouted |
B3004 |
Hampshire |
Zone 2 |
|
B3006 |
Hampshire |
Zone 2 |
|
B4640 |
West Berkshire |
Zone 3 |
|
B4666 |
Hinckley, Leicestershire |
Zone 5 |
The B4666 was formerly part of the A47. |
B4667 |
Hinckley, Leicestershire |
Zone 5 |
The B4667 was formerly part of the A447. |
B4668 |
Hinckley, Leicestershire |
Zone 5 |
The B4668 was formerly part of the A47. |
B4669 |
Leicestershire |
Zone 5 |
|
B5060 |
Telford |
Zone 4 |
|
B5061 |
Shropshire |
Zone 4 |
|
B5070 |
Wrexham |
Zone 4 |
The B5070 was formerly part of the A5. |
B5072 |
Telford |
Zone 4 |
|
B5444 |
Swansea |
Zone 4 |
There was previously, and still is, a B5444 in Mold, suggesting this numbering is also erroneous. |
B6241 |
Preston, Lancashire |
Zone 5 |
The B6241 was extended west of the A6. |
B6280 |
Darlington |
Zone 1 |
The A1 was re-routed, leaving its start-point out of zone. |
B6291 |
Durham |
Zone 1 |
The original section within Zone 6 was renumbered as an extension of the A688. |
B6420 |
Nottinghamshire |
Zone 1 |
The A1 was re-routed, leaving its start-point out of zone. |
B6469 |
Manchester |
Zone 5 |
|
B6541 |
Middlesborough |
Zone 1 |
The B6541 was formerly part of the A66. |
B9080 |
West Lothian |
Zone 8 |
The B9080 was formerly part of the A9. |
B9150 |
Highland |
Zone 8 |
The B9150 was formerly part of the A9. |
B9163 |
Highland |
Zone 8 |
A9 rerouted |
B9164 |
Highland |
Zone 8 |
A9 rerouted |
B9169 |
Highland |
Zone 8 |
A9 rerouted |
B9176 |
Highland |
Zone 8 |
The B9176 was formerly part of the A9 |
B9177 |
Highland |
Zone 8 |
The B9177 was formerly part of the A9 |
Road Number |
Location |
Reason |
A135 |
Stockton-on-Tees |
The other A13x roads are in southern England. |
A139 |
Stockton-on-Tees |
The other A13x roads are in southern England. |
A176 |
Basildon, Essex |
The other A17x roads are in North Yorkshire or County Durham. |
A180 |
Grimsby |
The other A18x roads are in the North-east. The A180 is numbered as an extension of the M180. |
A403 |
Avonmouth, South Gloucestershire |
The other A40x roads are in or around Greater London |
A437 |
Hillingdon, Greater London |
The other A43x roads are in Gloucestershire, Oxfordshire or Warwickshire. |
A500 |
Stoke-on-Trent "D"-road |
The other A50x roads are in London, southern England and Northamptonshire |
A506 |
Liverpool |
The other A50x roads are in London, southern England and Northamptonshire |
A594 |
one in Cumbria, one in Leicester |
There are two A594s which are clearly separate roads. |
A598 |
Barnet, Greater London |
The other A59x roads are in Cumbria (but see A594 above) |
A601(M) |
Carnforth, Lancashire |
"A601(M)" would be a designation for an upgraded section of the A601. The A601 is a completely different road in Derby. |
A1114 |
one in Chelmsford, one in Gateshead |
There are two A1114s which are clearly separate roads. |
A1199 |
one in Islington, one in Woodford (both in Greater London) |
There are two A1199s which are clearly separate roads. |