Last updated 2019-10-19, migrated 2023-04-10
Kilometer values appear in three ways:
On reflector poles (on all motorways and many expressways in England, Wales and Northern Ireland, and most motorways in Scotland
On large blue or green signs, called Driver location signs on all motorways and many expressways in England
On emergency telephones in orange. These values are imprecise and simply rounded to the nearest hm value.
This picture shows types 1 and 2 together:
Carriageways are identified by letters:
The reflector poles are usually on the side of the road but can also be in the middle. The driver location signs are always on the side and can be placed perpendicular to the road. They are not always very accurate and can be up to 30 m off. There are many sections where km values are stretched or compressed, notably on the M25 north. This is a histogram of the ratio between designated kilometerage and real distance:
More precisely, this is the multiplication factor required to go from distance as computed using OpenStreetMap to the kilometerage values.
NB 1 The distance on OSM is typically about 0.2 % too short due to the limited number of shape points in the data. This accounts for the more frequent occurrence of values between 1.00 and 1.01 compared to the 0.99 to 1.00 bucket.
NB 2 This histogram was obtained by weighing the correction factors by the distance between known points, for 985 sections. Since this evens out errors to some extent, the real situation for every km or hm separately would be slightly worse.
On M roads, the correction factors are closer to 1 than for A roads:
In all these charts, values under 0.8 and over 1.2 were omitted for display purposes. This excludes less than 0.05 % of sections weighted by distance.
km values generally run from west to east (e.g. A38, A55) and south to north (e.g. M6, A23), with many exceptions, e.g. M5 and M54, and roads to/from London tend to start in London.
Coverage: all motorways in England, Scotland and Wales, and selected expressways in England (and very few in Scotland and Wales). Total road length ca 5100 km.
If carriageways as more than 50 m apart, both carriageways are covered, otherwise only the positive direction (typically carriageway A).
Accuracy: at least 90 % within 50 m, at least 80 % within 25 m
Unit km, resolution 100 m
Locations from Google Streetview, tracks from openrouteservice.
Last updated 8-9-2018
Colours:
Sections:
1 London - Leeds
Increasing from 11.0 at London to 302.8 at Leeds
2 Leeds - Aberford
Increasing from 302.9 at Leeds to 319.7 at Aberford
Increasing from 43.1 at Chatham to 84.7 at Faversham
Increasing from 24.1 at London to 117.4 at Eastleigh
Sections:
1 London - Magor
Increasing from 12.1 at London to 207.1 at Magor
2 Magor - Fforest
Increasing from 209.8 at Magor to 320.5 at Fforest
3 Spur M4 - Heathrow Airport
Increasing from 0.2 at M4 to 1.6 at Heathrow Airport
Increasing from 0.0 at Birmingham to 262.0 at Exeter
km 4 on the northbound carriageway
Increasing from 132 at Catthorpe to 504.8 at Gretna
Near Wolverhampton
Increasing from 9.8 at Coleshill to 51.0 at Cannock
Sections:
1 Edinburgh - Airdrie
Increasing from 8.1 at Edinburgh to 47.5 at Airdrie
2 Airdrie - Langbank
Increasing from 49.7 at Airdrie to 99.3 at Langbank
Sections:
1 Newbridge - Stirling
Increasing from 12.2 at Newbridge to 53.5 at Stirling
2 Stirling bypass
Increasing from 53.6 at Stirling bypass to 63.4
Sections:
1 London - Cambridge
Increasing from 10.9 at London to 91.9 at Cambridge
2 Spur M11 - Hinxton
Increasing from 68.4 at M11 to 71.3 at the A11 in Hinxton
Increasing from 252.2 at Sheffield to 292.9 at Rawcliffe
Increasing from 27.8 at London to 109.9 at Folkestone
Increasing from 28.2 at London to 53.8 at Crawley
Sections:
1 Dartford - Sevenoaks
Increasing from 8.0 at Dartford to 25.0 at Sevenoaks
2 Sevenoaks - Grays
Increasing from 25.3 at Sevenoaks to 186.3 at Grays
Increasing from 0.0 at Orpington to 1.2 at M25
Increasing from 0.1 at M25 junction to 16.6 at Maidstone
The M26 has carriageways K and L instead of A and B. Thus from the carriageway identifier point of view, it is really a ramp from the M20 to the M25.
Increasing from 1.3 at Cadnam to 46.7 at Portsmouth
Increasing from 0.9 at Bristol to 8.0 at M4
Sections:
1 London - Birmingham
Increasing from 29.3 at London to 170.9 at Birmingham
2 Spur M40 - Wheatley
Increasing from 77.4 at M40 to 79.8 at Wheatley
Sections:
1 Birmingham southern ring road
Increasing from 0 at M5 to 18.2 at M40
2 Birmingham eastern ring road
Increasing from 18.8 at M40 to 38.0 at M6
3 Birmingham - Appleby
Increasing from 42.1 at M6 to 64.5 at Appleby
Increasing from 0.0 at M1 to 12.4 at Rugby
Increasing from 189.4 at Bristol to 209.4 at Magor
Increasing from 0.0 at Severn Beach to 10.3 at Avonmouth
Increasing from 0.5 at the M5 near Strensham to 34.6 at Ross-on-Wye
Sections:
1 Birkenhead - Chester
Increasing from 9.0 at Birkenhead to 40.2 at Chester
2 Spur Upton - M53
Increasing from 0.9 at Upton to 2.2 at M53
The section south of km 25 used to be the M531 until around 1985. The M53 was supposed to continue west of Chester.
Increasing from 0 at Wolverhampton to 35.4 at Wellington
At km 0.4 there is only a reflector pole
Driver location sign 100 m further down the road
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Increasing from 5.9 at Blackpool to 25.4 at Preston
The exit numbering runs in the opposite direction.
Sections:
1 Cheadle - Sharston
Increasing from 7.1 at Cheadle to 10.0 at Sharston where the road has a TOTSO with the A5103.
2 Sharston - Chester
Increasing from 10.2 at Sharston to 61.5 at Chester
Increasing from 3.5 at Tarbock to 19.6 at Aintree
Increasing from 10.3 at Aintree to 28.7 at Wigan
Sections:
1 Stockport - Whitefield
Increasing from 0.0 at Stockport to 31.4 at Whitefield
2 Whitefield - Stockport
Increasing from 32.3 at Whitefield to 56.8 ( = 0) at Stockport
The concurrent part with the M62 used to be numbered M62, the southern ring was the M63 and the eastern ring the M66. When the ring was completed in 2000, the whole ring was renumbered to M60.
Increasing from 1.9 at Manchester to 36.0 at Preston
Sections:
1 Liverpool - Manchester
Increasing from 6.0 at Liverpool to 43.5 at Whitefield
2 Manchester - North Cave
Increasing from 55.9 at Whitefield to 177.6 at North Cave
The Manchester northern ring road used to be the M62, but was renumbered to M60 when the ring was completed.
Increasing from 0.5 at Preston to 41.6 at Colne
Increasing from 0.0 at Edenfield to 14.1 at Whitefield
Increasing from 1.1 at Manchester to 8.6 at Hyde
Increasing from 99.3 at Coventry to 125.4 at Leicester
Increasing from 0.3 at Uddingston to 11.4 at Cumbernauld
Sections:
1 Glasgow - Johnstonebridge
Increasing from 0.0 at Glasgow to 99.3 at Johnstonebridge
2 Johnstonebridge - Gretna
Decreasing from 542.1 at Johnstonebridge to 504.9 at Gretna
This section is a continuation of the M6.
Increasing from 1.3 at the M8 in Glasgow to 29.0 at Kilmarnock
Increasing from 2.5 at the M8 in Glasgow to 36.9 at Stirling
Sections:
1 Kirkliston - Dunfermline
Decreasing from 12.3 at Kirkliston to 0 at Dunfermline
2 Dunfermline - Perth
Increasing from 0 at Dunfermline to 46.2 at Perth
Increasing from 0.0 at Thorne to 41.0 at Humberside Airport
Increasing from 8.3 at M180 to 12.4 at Scunthorpe
Increasing from 9.6 at Romsey to 13.2 at Southampton
Increasing from 299.2 at Cosham to 302.8 at Portsmouth
Increasing from 0.1 at Eccles to 6.8 at Manchester
Increasing from 0.4 at Cleckheaton to 4.6 at Bradford
Increasing from 0.2 at Morley to 13.6 at Leeds
Sections:
1 Cumbernauld - Falkirk
Increasing from 26.9 at Cumbernauld to 35.4 at the M9 near Falkirk
2 Falkirk - Kincardine
Increasing from 37.3 at the M9 near Falkirk to 39.7 at Kincardine
A 2 km section is concurrent with the M9, which is taken into account in the kilometerage, but the M9 has different values.
Increasing from 0.0 at the M8 to 1.6 at Erskine
Sections:
1 London - Baldock
Increasing from 22.5 at London to 62.0 at Baldock
2 Huntingdon - Peterborough
Increasing from 5.5 at Huntingdon to 26.0 at Peterborough
3 Blyth - Doncaster
Increasing from 0.0 at Blyth to 24.5 at Doncaster
4 Knottingley - Aberford
Increasing from 36.5 at Knottingley to 54.6 at Aberford
5 Aberford - Ripon
Increasing from 54.9 at Aberford to 95.5 at Ripon
6 Ripon - Scotch Corner
Increasing from 100.0 at Ripon to 138.9 at Scotch Corner
7 Scotch Corner - Gateshead
Increasing from 0.0 at Scotch Corner to 54.4 at Gateshead
Decreasing from 9.3 at Waterlooville to 0.0 at Havant
The A3(M) id the only road that has carriageway A with decreasing values. Exit numbering does increase along carriageway A.
Increasing from 380.4 at Birmingham to 383.9 at Erdington
Increasing from 232.2 at the M4 to 235.8 at Cardiff
Increasing from 0.0 at the A1(M) to 3.5 at Blackwell
Increasing from 53.5 at Birtley to 59.4 at South Shields
km values are derived from the A1(M).
Increasing from 45.1 at the M4 to 46.0 at the A308 in Maidenhead
Increasing from 6.2 at Reading to 14.1 at Bracknell
Increasing from 45.2 at the M4 to 49.0 at the A404 west of Maidenhead
Continues as A404 to High Wycombe
Increasing from 0.0 at Carnforth to 1.4 at the M6
Increasing from 0.1 at Oldham to 5.8 at Rochdale
Sections:
1 Baldock - Huntingdon
Increasing from 62.3 at Baldock to 105.3 at Huntingdon
2 Peterborough - Blyth
Increasing from 26.1 at Peterborough to 144.5 at Blyth
3 Doncaster - Knottingley
Increasing from 285.2 at Doncaster to 297.5 at Knottingley
Increasing from 12.9 at London to 43.3 at Chatham
Increasing from 0.0 at London to 48.6 at Haslemere
Sections:
1 Dunstable - Old Stratford
Increasing from 69.0 at Dunstable to 84.3 at Old Stratford
2 Wellington - Shrewsbury
Increasing from 35.6 at Wellington to 46.1 at Shrewsbury
Increasing from 0.0 at the M25 to 24.7 at Ware
Increasing from 71.5 at Hinxton to 90.3 at Newmarket
km values seem derived from the M11 spur but deviate by about 50 m.
Increasing from 99.9 at London to 184.2 at Ipswich
Increasing from 94.0 at London to 112.9 at Basildon
Sections:
1 Catthorpe - Huntingdon
Increasing from 0.0 at Catthorpe to 72.7 at Huntingdon
2 Huntingdon - Cambridge
Increasing from 72.7 at Huntingdon to 94.6 at Cambridge
3 Cambridge - Felixstowe
Increasing from 95.8 at Cambridge to 207.8 at Felixstowe
Increasing from 0 at the M180 near Humberside Airport to 16.3 at Kingston upon Hull
Increasing from 0.0 at Brighton to 25.9 at Crawley
Increasing from 46.7 at Cosham to 67.3 at Chichester
Sections:
1 Penzance - Exeter
Increasing from 29.3 at Penzance to 196.4 at Exeter
2 Exeter - Honiton
Decreasing from 255.0 at Exeter to 232.0 at Honiton
Sections:
1 Winchester - Newbury
Increasing from 0.0 at Winchester to 45.5 at Newbury
2 Newbury - Bicester
Increasing from 43.1 at Newbury to 98.3 at Bicester
The discontinuity at Newbury shows that the kilometerage was assigned before the opening of the Newbury bypass in 1998.
Increasing from 67 southeast of Salisbury to 75 at Whaddon
Sections:
1 Bodmin - Exeter
Increasing from 2 at Bodmin to 111.8 at Exeter
2 Lichfield - Mansfield
Increasing from 408.9 at Lichfield to 471.8 at the M1 near Mansfield
Increasing from 79.9 at the M40 spur near Wheatley to 86.8 at Oxford
km values are derived from the M40 spur.
Increasing from 30.5 at London to 58.4 at Aylesbury
Increasing from 64.7 at Appleby to 87.4 at Nottingham
Increasing from 232 at Rugby to 243 at Coventry
Sections:
1 Warwick - Coventry
Increasing from 76 at Warwick to 92 at Coventry
2 Coventry bypass
Increasing from 92 to 99.5 at the M69
3 Leicester - Syston
Increasing from 0 at the M1 near Leicester to 12.4 at Syston
4 Newark-on-Trent - Lincoln
Increasing from 71 at the A1 in Newark-on-Trent to 85.4 at the Lincoln bypass
Increasing from 71.3 at the M1 near Nottingham to 136.9 at the A500 in Stoke-on-Trent
Sections:
1 Holyhead - Ewloe
Increasing from 0.0 at Holyhead to 120.8 at Ewloe where the road has a TOTSO with the A494.
2 Ewloe - Chester
Increasing from 120.4 at Ewloe to 141.0 at Chester
Sections:
1 Edenfield - Haslingden
Increasing from 0.2 at Edenfield to 2.5 at Haslingden where the road has a TOTSO with the A682.
2 Haslingden - Hapton
Increasing from 2.7 at Haslingden to 14.5 at Hapton
Increasing from 177.7 at North Cave to 202.0 at Kingston upon Hull
Values are a continuation of the M62.
Increasing from 0 at the A1(M) near Leeds to 30.2 at York
Increasing from 150 at Colchester to 163.8 at Horsley Cross
Increasing from 94.5 at London to 127.0 at Southend
Increasing from 41.0 near Humberside Airport to 62.5 at Grimsby
Values are a continuation of the M180.
Increasing from 0.8 at Grays to 7.9 at Guildford
Values continue on the M25.
Increasing from 84.8 at the M3 west of Basingstoke to 170.3 at Mere
Values are derived from the M3.
Increasing from 49 at Maidenhead to 60.6 at High Wycombe
Values are derived from the A404(M).
Increasing from 32.3 at St Albans to 37.8 at Hemel Hempstead
This section used to be the M10 until 2008.
Increasing from 23.7 at Cirencester to 42.6 at Birdlip
Increasing from 0 at the M4 in Swindon to 23.7 at Cirencester
Increasing from 0.0 at Milton Keynes to 28.5 at St Neots
Increasing from 1.0 at Chester to 11.9 at the A55 in Ewloe
Increasing from 0.0 at Stoke-on-Trent to 18.6 at Nantwich
Increasing from 0 at the A1 east of Edinburgh to 20.5 at Gogar
Increasing from 9 at the A13 in Grays to 13.7 at Tilbury
According to Highways England, the positive direction is carriageway B.
Increasing from 8.2 at Manchester to 10.1 at the M56 in Sharston
Values continue on the M56.
Increasing from 0 at the M6Toll to 2.5 at the A38 in Lichfield
Signs on A roads are always green except on the A5148.
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Fusion table with the hm points
Marcel Monterie