# B roads in Zone 4 of the Great Britain numbering scheme

B roads are numbered routes in Great Britain of lesser importance than A roads. See the article Great Britain road numbering scheme for the rationale behind the numbers allocated.

## 3 digits

| Road | From | To | Notes |
| B400 | A4 Fleet Street | A40 Holborn | Chancery Lane. One way only Northbound |
| B401 | A40 High Holborn | B402 Long Acre | Endell Street. One way only Southbound. Formerly included Bow Street and Wellington Street further south. |
| B402 | A400 Charing Cross Road | A4200 Kingsway | Road Names: Cranbourn Street, Long Acre, Great Queen Street. One-way westbound along Cranbourn Street; one-way eastbound along Long Acre. |
| B403 (defunct) | A40 New Oxford Street, London | B401 Endell Street, London | Now part of the A40 one-way system. |
| B404 | A401 Shaftesbury Avenue | A400 Charing Cross Road | Road Names: Monmouth Street, Upper St Martin's Lane, St Martin's Lane. One-way southbound. Crosses Seven Dials and south end is near St Martin-in-the-Fields, the National Gallery and Trafalgar Square. |
| B405 | A4204 Palace Gardens Terrace, near Notting Hill Gate | A4204 Kensington Church Street | Road Names: Palace Gardens Terrace, Vicarage Gate. Originally ran along the north side of Trafalgar Square; later upgraded to a loop off the A4. The section along Trafalgar Square is now pedestrianized and the remainder is part of the A4. |
| B406 | A5204 Wigmore Street, Marylebone | A4201 Regent Street, Mayfair | Road Names: Welbeck Street, Henrietta Place, Vere Street, New Bond Street, Conduit Street. One-way southbound except along Conduit Street. |
| B407 (defunct) | A4 (now A315) Kensington High Street, London | A40 Holland Park Avenue, London | Upgraded to Class I status as a portion of the A3220. Southern third is now one-way northbound. |
| B408 | A315 King Street, Hammersmith | A4020 Shepherd's Bush | Road Names: Dalling Road, Paddenswick Road, Askew Road. South part of Dalling Road is one-way southbound. |
| B409 | A402 Goldhawk Road, Stamford Brook | B490 at Acton Green | Road Names: Stamford Brook Road, Bath Road, South Parade |
| B410 | A402 Bayswater Road | A4205 Praed Street at Paddington station | Road Names: Leinster Terrace, Craven Hill, Craven Road |
| B411 | A402 Bayswater Road | A404 Harrow Road | Road names: Queensway, Porchester Road, Lord Hills Bridge. Also includes Inverness Place and Inverness Terrace, for one-way southbound traffic (south part of Queensway is one-way northbound). |
| B412 | A219 Shepherd's Bush | A4207 Notting Hill | To the West of Ladbroke Grove it follows North Pole Road, St Quentin Avenue, St Marks Road and Cambridge Gardens. To the East, through Westbourne Park Road. Crosses Portobello Road. |
| B413 | A5 Maida Vale | B450 Chamberlayne Road | In two parts: Maida Vale to Kilburn Park Road, and Kilburn Park Road to Kensal Green. Via Warwick Avenue Underground station. Road Names: Clifton Road, Clifton Gardens, Warwick Avenue, Formosa Street, Shirland Road, Carlton Vale, Kilburn Lane |
| B414 | A5 Maida Vale | A404 Harrow Road at Westbourne Green | Road Names: Kilburn Park Road, Walterton Road, Fernhead Road |
| B415 | A4206 Pembridge Road, near Notting Hill Gate | B450 Ladbroke Grove | Road Names: Kensington Park Road, Elgin Crescent |
| B416 | A4 Wellington Street / A332 roundabout at Slough | A413 Amersham Road at Gerrards Cross | |
| B417 - B423 | unused | | |
| B424 (defunct) | | | Possible typo for the B454. |
| B425 | A45 in Sheldon, West Midlands | A41 in Solihull | |
| B430 | A34 at Weston-on-the-Green | M40 at Ardley | The original route of the A43. |
| B431 - B438 | unused | | |
| B439 | A46 at Salford Priors | A4390 at Stratford-upon-Avon | Formerly the A439 |
| B440 | A4146 and A505 roundabout at Leighton Buzzard | A4146 and A4147 in Hemel Hempstead | Downgraded non-primary section of the A4146, created in 2017 as part of a wider renumbering related to the A5 Dunstable bypass. |
| B441 - B449 | unused | | |
| B450 | A402 at Holland Park | B451 at Kensal Rise | Much of this is Ladbroke Grove in Notting Hill and passes close to Portobello Road market. |
| B451 | A404 at Kensal Green | A5 at Kilburn | Via Kensal Green railway station. Road Names: College Road, Mortimer Road, Harvist Road, Brondesbury Road |
| B452 | A3002 at Brentford | A40 at Perivale | Via Brentford railway station, Northfields Underground station and West Ealing railway station. Road Names: Windmill Road, Northfield Avenue, Drayton Green Road, Argyle Road, Teignmouth Gardens Originally ran from Willesden to Neasden. Upgraded to Class I status as the A4088 in the mid-1920s. |
| B453 | A407, Willesden High Road, Willesden | A4088, Neasden Junction | Passes Neasden Underground Station (Jubilee line) |
| B454 | A315 at Isleworth | A4127 at Southall | Via Syon Lane railway station, and crosses Osterley Park. Road Names: Spur Road, Syon Lane, Windmill Lane. |
| B455 | A315 at Brentford | A312/A4180 roundabout at Yeading | Via South Ealing Underground station and Ealing Broadway railway station. Road Names: Ealing Road, South Ealing Road, Saint Mary's Road, Ealing Green, Bond Street, Ealing High Street, Ealing Broadway, Haven Green, Castlebar Road, Castlebar Hill, Kent Gardens, Scotch Common, Ruislip Road East, Greenford Broadway, Ruislip Road. Haven Green, Ealing Broadway and Ealing High Street are one-way southbound; Bond Street is one-way northbound. |
| B456 | A40 Western Avenue | A4005 at Alperton | Road Name: Alperton Lane |
| B457 (defunct) | A4005 at Roxeth | A312 at Harrow | Now part of a rerouted A4005. |
| B458 (defunct) | A404 in Harrow | A4005 in Harrow | Declassified as it is within Harrow's ring road, and is now one-way westbound. |
| B459 (defunct) | A410 in Harrow Wield | A410 in Stanmore | Declassified after the 1990s. |
| B460 (defunct) | A410 in Hatch End | A41 in Oxhey | Upgraded to Class I status as the A4008 in the 1940s. |
| B461 | A4140 at Stanmore | A5 at Edgware | Whitchurch Lane, past Canons Park station |
| B462 | A411 at Bushey Arches | A5183 at Radlett | |
| B463 (defunct) | A404 in Pinner | A410 in Pinner | Declassified after the 1990s after the rerouting of the A404 north of Pinner. |
| B464 (defunct) | A312 north of Harlington | A40 (now A4020) in Hillingdon | Renumbered to A437; the southernmost section is unclassified. |
| B465 | A4020 at Hillingdon | A408 at Stockley Park | Road Name: West Drayton Road |
| B466 | A4020 at Hillingdon | A404 at Pinner | Via West Ruislip railway station. Road Names: Long Lane, Ickenham High Road, Ickenham Road, Eastcote Road, Eastcote High Road, Cuckoo Hill |
| B467 | A4020 at Uxbridge | B466 at Ickenham | Road Names: Harefield Road, Swakeleys Road |
| B468 (defunct) | A404 near Northwood | A40 (now A411) in Oxhey | Upgraded to Class I status as the A4125. |
| B469 | A404 at Northwood | A4215 at Northwood | Via Northwood Underground station. Road Name: Green Lane |
| B470 | A408 at Cowley | A4 at Windsor | Via Langley railway station. |
| B471 | Pangbourne, Berkshire | A4074 at Woodcote, Oxfordshire | Originally ran from Iver Heath to Denham (now the A412). The northernmost section was later cut in two by the M40 and the old B471, Southlands Road, now goes nowhere. |
| B472 | A404 at Northwood Hills | B466 at Eastcote | Via Northwood Hills Underground station. Road Name: Joel Street First used from Slough to Chalfont St Peter; this was upgraded in the 1920s to a portion of a rerouted A332. Reused along old B473 from Beaconsfield to Amersham when the B473 was rerouted to Hazelmere, but became the B473 (now A355) again in 1935. |
| B473 (defunct) | A4 at Slough | A413 in Amersham | Rerouted to Hazelmere when the A332 replaced the original B472, with the original route to Beaconsfield renumbered to B472. In 1934 the B473 was proposed to be extended south along the B3027, replacing the B474 as a spur to the A332, and rerouted along the B472 to Amersham, with the Beaconsfield-Hazelmere section numbered as a B road (not as B472, however). The extension south was rejected in January 1935 as it would have put the B473 out-of-zone, but the other proposals proceeded as planned and were implemented in April 1935. The Beaconsfield-Hazelmere section was numbered as the B474. Due to an increase of traffic, the B473 was upgraded to Class I status as an extension of the A355 in the 1970s. |
| B474 | A40 at Beaconsfield | A404 at Hazlemere | Former portion of B473. Originally ran from Stoke Poges to Farnham Royal; it was renumbered as a spur of the B473 in 1935. Now part of the B416. |
| B475 (defunct) | A4 in Slough | Slough railway station | Declassified in the 1960s when the A4 was rerouted. |
| B476 (defunct) | A4 near Taplow | A32 (now A4094) in Wooburn | Downgraded because it paralleled the A4094. Now MC61 and C172. |
| B477 | A4 at Hare Hatch | A321 at Wargrave | Narrow with virtually no white line markings in centre of road. |
| B478 | A4 road at Charvil | A4155 (former A32) | via Sonning |
| B479 (defunct) | A32 in Caversham | A423 in Benson | Originally ended at the A42 in Streatley, but was rerouted in the 1930s to Benson, with the old route becoming B4526 and B4008 (now B4009). When the A423 was cut in half by the runway at RAF Benson, the B479 was rerouted out of Benson entirely. The section between Benson and the A4130 at Crowmarsh Gifford became a portion of a rerouted A423 in the 1960s with the remainder upgraded to the A4074, which would also replace the A423 after it was rerouted. |
| B480 | A4130 Fair Mile, Henley-on-Thames | The Plain, Oxford | |
| B481 | A4155 Caversham | B480 just south of Watlington | Connects Reading to B4009 at Watlington and hence the M40 2.5miles north of Watlington |
| B482 | A4155 Marlow | A40 Stokenchurch | By way of Lane End, Bolter End and Cadmore End |
| B483 | A4020 at Uxbridge | A40 at Ickenham | Road Name: Park Road |
| B484 (defunct) | A416 at High Wycombe railway station | A416 at Wycombe Abbey | Became a portion of the A404 in 1935. |
| B485 | A416 at Chesham | A413 at Great Missenden | |
| B486 | B4635 in Tring | B488 in Tring | Former portion of the B488 before it was rerouted. Originally ran from Boxmoor to Leighton Buzzard (now A4146, A4012 and B440). |
| B487 | Hemel Hempstead | A1081 in Harpenden | |
| B488 | Aston Clinton, Tring | A4146 south of Leighton Buzzard, | Begins at a grade separated junction east of Aston Clinton. |
| B489 | B4009 at Aston Clinton | A5/A505 at Dunstable | Formerly started on the A41, now crosses the bypassed A41 and starts in Aston Clinton on the B4009. |
| B490 | A315 at Chiswick | A4020 at Acton | Via Chiswick Park Underground station. Road Names: Acton Lane, Beaconsfield Road, Acton Lane, Winchester Street |
| B491 | A315 at Chiswick | B490 near Acton | Via Turnham Green Underground station. Road Names: Turnham Green Terrace, The Avenue, Southfield Road |
| B492 (defunct) | A40 in Acton | A4000 in Acton | Now part of the A4000 one-way system. |
| B493 - B499 | unused | | |

## B4000 to B4099

| Road | From | To | Notes |
| B4000 | A4/A34 at Speen, Berkshire | A361 at Highworth, Wiltshire | Via Lambourn, Ashbury and Shrivenham |
| B4001 | A4 at Hungerford, Berkshire | A417 north of West Challow | Via Lambourn |
| B4002 (defunct) | New Road, Marlborough | The Common, Marlborough | Now part of the A346. |
| B4003 | A4 near West Overton | A4361 at Avebury | Single track throughout length. |
| B4004 (defunct) | A361 in Broad Hinton | A420 in Wootton Bassett | Renumbered as a southern extension of the B4041 in 1935. Now unclassified. |
| B4004 (defunct) | A48 in Coldra | B4237 in Newport | The former classification of Ringland Way in Newport. Upgraded to Class I status as the A455 by 1968 and is now part of a rerouted A48 as a portion of the Southern Distributor Road. |
| B4005 | M4 J16 at Swindon and Wootton Bassett | A346 road east of Chiseldon | Via Wroughton |
| B4006 | A3102 in West Swindon | A4361 north of Wroughton | Incomplete orbital route through suburbs of Swindon. Begins west of the centre as part of Great Western Way then orbits north and east, becoming Dorcan Way in the east, and continues through southern suburbs. |
| B4007 (defunct) | A415 on Harcourt Hill | A417 in Harwell | Due to its importance, it was renumbered to A4130 in the early 1930s. The eastern end became a portion of a rerouted A423, but later returned to the A4130 after the A423 was rerouted in the 1990s. A small section in Didcot is now the B4016 and the section between Didcot and Harwell is now the B4493. |
| B4007 (defunct) | A329 Broad Street, Reading | A4155 Caversham Road, Reading | via Queen Victoria Street, Station Road and Tudor Road; declassified by the 1980s. |
| B4008 | Stroud | Quedgeley | Formerly part of the A419. Originally ran from Crowmarsh Gifford to Benson. Extended south via North Stoke to the B479 in Goring in the late 1920s. The section north of Crowmarsh Gifford (including the entire original section) became part of a rerouted B479 in the early 1930s and the section of old B479 between Goring and the A42 at Streatley became a portion of the B4008. This became a portion of an extension of the B4009 in 1935. |
| B4009 | A4 / A339 at Newbury | A41 at Tring, Hertfordshire | Exists in two sections, connected by the A4074. |
| B4011 | A418 at Thame | A41 near Bicester | Via Long Crendon. Turnpiked in 1833. |
| B4012 | A40 at Postcombe | A4129 at Thame | Forms eastern bypass for Thame. Originally met B4011 in town centre. |
| B4013 (defunct) | A4074 in Shillingsford | A418 west of Thame | Upgraded to the A329 when the M40 opened. |
| B4014 | A429 north of Malmesbury | A46 at Nailsworth | Via Tetbury and Avening; formerly part of the A434. Originally ran from Oxford to Stadhampton. Renumbered as a western extension of the B480 in 1935. |
| B4015 | A415 Clifton Hampden | B480 Chiselhampton | |
| B4016 | B4017 Drayton | A417 Blewbury | Via Sutton Courtenay, Appleford-on-Thames and East Hagbourne |
| B4017 | B4044 Farmoor | A4130 Milton Hill | Via Cumnor, Abingdon and Drayton. The section of road between Abingdon and Milton Hill was formerly part of the A34. |
| B4018 (defunct) | B4017 Bath Street, Abingdon | A34 Stert Street, Abington | Ran along Broad Street. Became a spur of the B4017 in 1935 and the A415 in the 1950s. It is now unclassified and mostly pedestrianized. |
| B4018 (defunct) | A4059 Brecon Road, Hirwaun | A465 in Cwm Ynys-Mintan | Former section of the A465 east of Hirwaun, designated in 1965 when the Heads of the Valleys Road opened. Now unclassified. |
| B4019 | Faringdon, Oxfordshire | A419 at Broad Blunsdon, Wiltshire | Via Highworth |
| B4020 | A40 at Burford | A4095 at Clanfield | Originally continued along present A4095 to Faringdon. Diverted from previous route when runway at RAF Brize Norton extended. |
| B4021 (defunct) | B4020 in Clanfield | A40 near Witney | Upgraded to Class I status as a portion of the A4095 in the mid-1920s. |
| B4021 (defunct) | A420 at Stratton Park | A419 near Broad Brunston | Trunked in 1946 (designated T43) and became a portion of the A419 shortly after. The route has since been bypassed, although the central section is now the B4006. |
| B4021 (defunct) | Rectory Road, Rickmansworth | Church Street, Ricksmanworth | Included a spur along Station Road; formerly the A404 and A412 before they were rerouted out of town. Now unclassified. |
| B4022 | A40 at Cogges, Oxfordshire | A361 near Great Tew | Via Witney, Charlbury and Enstone. The former route of the A40 between Cogges and Witney |
| B4023 (defunct) | A40 Tower Hill, Witney | A40 High Street, Witney | Became a portion of a rerouted A40 in 1930. The route is now part of the A4095 after the Witney bypass was built. |
| B4023 (defunct) | A419 (now A41) and B4070 (now unclassified) at the Air Balloon roundabout | A40 in Andoversford | Upgraded to Class I status as the A436 in 1935. |
| B4024 | B4215 near Dymock | A449 in Much Marcle | Originally ran from the A40 at Witney to the A42 near Woodstock. Like many of the B402x roads, it was upgraded to the A4095 in the mid-1920s. The last quarter-mile section however became the A4114 because the A4095 replaced the B4025, instead of the B4024, at the Woodstock end. This later became a spur of the A4095 and is now unclassified. |
| B4025 | A34 in Hall Green, Birmingham | A41 at Solihull | First used between the B4024 and A42 south of Woodstock. Upgraded early on (before 1925) to Class I status as the A4095. Next used in 1925 along an old section of the A38 to the east of Norton. Appears on maps up to 1934, but not on 1936 or 1937 maps. Downgraded to a C-road by the 1940s and is now little more than a farm track. |
| B4026 | A3400 (old A34) near Over Norton | B4437 in Charlbury | Previously continued to B4022. |
| B4027 | A40 at Wheatley | A44 at Glympton | By way of Beckley. Also used in Warwickshire between Binley and Cross in Hand. This was previously the B4114, then upgraded to the A4114 in the 1940s and renumbered to the A427 in the 1960s and had the B4027 number by the 1990s, probably for continuity, but because the number was in use elsewhere, it was renumbered to the B4428 in the 2000s. |
| B4028 | B4228 in Coleford | A4136 at Edge End | Prior to construction of Coleford relief road, met B4228 in Market Place. Via Mile End. First used from the A42 (now A44) in Woodstock to the A423 (now A4260) at Sturdy's Castle. Declassified in the mid-1920s due to completion of the A4095, which ran parallel to the B4028. |
| B4029 | B4113 at Bedworth | B4428 near Brinklow | Via Bulkington. Previously continued along present B4455 to Brinklow. Continued along now unclassified road to Ryton. Originally ran from the B4027 at Enslow to the B4030 west of Bicester. Like many of the B402x roads, it was upgraded to the A4095 in the mid-1920s, however it did not follow Akeman Road between Kirtlington and Chesterton but followed the next road north. The section along Akeman Road was declassified instead. |
| B4030 | A44 near Enstone | B4100 at Bicester Town Centre | Via Church Enstone, Gagingwell, Westcott Barton, Middle Barton, Bartongate, Hopcroft's Holt, Lower Heyford and Middleton Stoney. Turnpiked in 1797 and disturnpiked in 1876. |
| B4031 | A361 near Great Tew | A43 near Croughton, Northamptonshire | Via Deddington |
| B4032 | A413 near Winslow | A4146 at Linslade | |
| B4033 | A413 near Winslow, Buckinghamshire | A421 near Nash, Buckinghamshire | |
| B4034 | A421 in south western Milton Keynes | A422 in northern Milton Keynes | Concurrent with V8 Marlborough Street from A422/H3 Monks Way to A421/H8 Standing Way. Concurrent with V7 Saxon Street from A421 to Brunel Roundabout, Bletchley. From this roundabout the road heads west to meet with the A421 and the southern terminus of V1 Snelshall Street. |
| B4035 | Banbury | A4184 in Evesham | Via Broughton, Tadmarton, Swalcliffe, Brailes, Shipston-on-Stour, Chipping Campden, Bretforton and Badsey |
| B4036 | Daventry | A5 at Long Buckby Wharf | Formerly continued to Market Harborough via Naseby, site of the English Civil War battle of that name, and ran close to a junction with the A14 and M1 junction 18 |
| B4037 | A361 at Badby | A45 near Dodford | Via Newnham. |
| B4038 | A361/A5 at Kilsby | A428 at Hillmorton | Can be accessed from the A5 or A361. Formerly much longer as it continued along what is now part of the A361 between Daventry and Kilsby. Today the road is only about 3 miles (5 km) long, linking Kilsby and Rugby, whilst bypassing J18 of the M1. |
| B4039 | A420 west of Chippenham | B4040 at Acton Turville | |
| B4040 | A46 at Old Sodbury, South Gloucestershire | A419 at Cricklade, Wiltshire | Via Malmesbury |
| B4041 (defunct) | A419 in Cricklade, Wiltshire | A4361 near Broad Hinton, Wiltshire | Via Wootton Bassett. Originally ended at the A420 (now A3102) at Wooton Bassett, but was extended over the B4004 to Broad Hinton in 1935. Declassified in the late 1980s, but the northernmost section, from Cricklade to north of Purton, is now part of the B4553. |
| B4042 | A429 in Malmesbury, Wiltshire | A3102 in Wootton Bassett, Wiltshire | |
| B4043 | A458 in Quinton, West Midlands | A456 in Halesowen, West Midlands | Originally ran along Midland Bridge Road in Bath. The route was put out-of-zone when the A4 was extended north in 1935 and was renumbered to B3118 as a result. The northern end is now part of the A367 due to later developments in Bath. |
| B4044 | A420 at Botley | A40 at Eynsham | Passes over Swinford Toll Bridge. Part of the A40 until the 1930s, later renumbered as the A4141. Originally ran along Newbridge Road in Bath. Upgraded to a portion of the A4 in 1935. |
| B4045 (defunct) | A36 in Keynsham | A431 at Willsbridge | Became a portion of the B4427 in the 1935 renumbering, and is now part of the A4175. |
| B4045 (defunct) | | | Appears in the 2005 DfT list as "Link in Malmesbury". The road does not exist, but it may have before the A429 bypass was built, although there is no obvious location for the road. |
| B4046 | A420 in Kingswood, South Gloucestershire | A431 in Hanham | |
| B4047 | Witney, Oxfordshire | A40 west of Minster Lovell | Former route of the A40. Originally ran from Warmley to Fishponds. In the 1935 renumbering, the section from Warmley to Staple Hill was renumbered to B4427 (now A4175) and the remainder to B4465. The southern section was split in two by the A4174 and is now unclassified and closed to through traffic. |
| B4048 | A432 in Fishponds, Bristol | A4017 near Kingswood, South Gloucestershire | Lodge Causeway |
| B4049 (defunct) | A430 (now A420) in Lawrence Hill, Bristol | B4047 in Fishponds | Much of route became part of the B4465 in 1935; route now split in two by the Lawrence Hill roundabout. |
| B4050 (defunct) | A38 at the Haymarket, Bristol | B4051 Lower Ashley Road, Bristol | Now part of the A4032. |
| B4051 | A4018 at Park Street top, Bristol | M32 J3 | Park Row, Marlborough St and Ashley Road |
| B4052 | B4051 at Sussex Place, Bristol | A38 at Horfield, Bristol | Ashley Hill and Ashley Down Road |
| B4053 | The Centre, Bristol | Temple Gate, Bristol | Baldwin Street, Bristol Bridge and Victoria Street Originally ran along Colston Street and Jamaica Street in Bristol. Renumbered as a western extension of the B4051 in 1935. |
| B4054 | A38 at Gloucester Road, Bristol | A4 at Avonmouth | Cranbrook Road, Parry's Lane and Shirehampton Road |
| B4055 | A4018 at Westbury-on-Trym, Bristol | New Passage | The route is in two parts separated by a mile of the A4018. One runs from Westbury-on-Trym through Henbury to the south end of Cribbs Causeway and the other from J17 of the M5 to New Passage. |
| B4056 | A4018 at Durdham Down, Bristol | A38 at Filton | Henleaze Road and Southmead Road |
| B4057 | B4054 at Kingsweston | A4018 at Brentry | Part One |
| B4057 | A38 at Patchway | B4058 at Winterbourne, Gloucestershire | Part Two: the two parts are separated by Filton Airfield, and were connected before the runway was extended in 1949. |
| B4058 | A432 at Eastville, Bristol | A46 at Nailsworth | |
| B4059 | A432 at Yate | B4427 at Earthcott | Via Iron Acton; exists in two sections, connected by the B4058. |
| B4060 | A432 at Yate | A4135 at Cam | Via Wotton-under-Edge |
| B4061 | A38 at Alveston, Glos | A38 near Whitfield | Connects Thornbury with the A38 |
| B4062 | B4058 east of Charfield, Gloucestershire | B4060 at Kingswood, Stroud District | |
| B4063 | A40 west of Cheltenham | Gloucester | Formerly part of the A40. Originally ran from Wotton-under-Edge to Symonds Hall. Renumbered as an eastern extension of the B4058 in 1935. |
| B4064 | B4055 in Pilning | Severn Beach and New Passage | Has three arms at roundabout close to M4. Section to New Passage part of B4055 until 1930s. Originally ran from Wotton-under-Edge to Cam. Renumbered as a northern extension of the B4060 in 1935. |
| B4065 | A38, north of Droitwich | B4090 in Droitwich town centre | Former route of A38. Originally ran near Dursley, cutting the corner between the B4064 and B4066 (later A4135). Renumbered as a portion of a new B4066 in the 1935 renumbering. |
| B4065 | M6 Anstey Interchange (J2) | B4109 at Wolvey | Duplicate number. Former route of A46. |
| B4066 | A419 at Dudbridge, Gloucestershire | Sharpness | Via Dursley and Berkeley, the section near Dursley is the original B4065. Originally ran between Tetbury and Cambridge. Upgraded to the A4135 around 1930. |
| B4067 (defunct) | A433/A434 in Tetbury | A433 in Tetbury | Declassified after the 1970s, likely in favor of the A433. |
| B4068 | A436 west of Naunton, Gloucestershire | Stow-on-the-Wold | Originally a loop off the A38 in Berkeley. The northern section became a portion of the B4066 and the remainder a northern extension of the B4509. Only a mile of the ex-B4068 still exists as the B4066, while the remainder is now unclassified, probably due to narrow streets. |
| B4069 | A3102 north of Lyneham | Chippenham, junction with A420 | Formerly part of the A420. First used between Cirencester and Stroud. Due to its importance, it was upgraded to Class I status as the A4116 (now A419) in the mid-1920s. Next used from The Quarry to the A38. Renumbered as a western extension of the B4066 in 1935. Used a third time from Hinckley to Sapcote, despite the number being out-of-zone. Renumbered to the B4669 (still out-of-zone) in the 1990s (along with many other roads in Hinckley) when the A47 northern bypass was built. |
| B4070 | A417 at Birdlip, Gloucestershire | Stroud | Originally ran from Stonehouse to Claypits. Due to its importance, it was upgraded to Class I status as the A4096 in the mid-1920s. Much of route now part of a rerouted A419; the western section is now unclassified as the A419 was routed away from Eastington to the M5. |
| B4071 | A38 south of Whitminster, Gloucestershire | Saul, Gloucestershire | |
| B4072 | Gloucester | A38 at Tuffley | |
| B4073 | Gloucester | A46 at Painswick | |
| B4074 (defunct) | Barnwood | Longlevens | Elmbridge Road; cut the corner between the A419 (now A417) and A40 (now B4063). Later extended along the kink of Old Cheltenham Road when the A40 was rerouted. Now unclassified, likely due to completion of the A40 bypass. |
| B4075 | A435 near Cheltenham Racecourse | A40, London Road, Cheltenham | Via Prestbury |
| B4076 | A4114 in Allesley | Brownshill Green Road | Called Coundon Wedge Drive, it was built to serve the main gates of the now closed Jaguar Browns Lane site. Previously all traffic had to use Browns Lane to access the A4114/A45. Originally ran along Gloucester Road in Cheltenham, connecting Lansdown railway station to the A40 and A4019. Later renumbered as a counterclockwise extension of the B4075 and is now part of the B4633. |
| B4077 | A46 & A435 at the Teddington Hands east of Tewkesbury | A429 in Stow-on-the-Wold | Via Teddington, Toddington, Stanway, Ford and Upper Swell |
| B4078 | Winchcombe, Gloucestershire | A46 at Sedgeberrow | |
| B4079 | B4080 at Bredon, Worcestershire | A46 at Aston Cross, Gloucestershire | Via Kinsham and Aston on Carrant |
| B4080 | A4104 at Defford, Worcestershire | A38 at Tewkesbury, Gloucestershire | Via Eckington, Bredon's Norton, Bredon and Bredon's Hardwick |
| B4081 | A44 west of Blockley, Gloucestershire | B4632 at Mickleton | Via Chipping Campden. A road of the same number previously ran from Wyken to Willenhall |
| B4082 | A422 at Upton Snodsbury, Worcestershire | A44 at Pinvin, Worcestershire | Via Naunton Beauchamp |
| B4082 | A428 at Binley | B4113 (old A444) at Little Heath | Duplicate number. Partly occupies original A4082 route. |
| B4083 | A44 at Pinvin, Worcestershire | A4104 at Pershore, Worcestershire | Via Wyre Piddle |
| B4084 | A4184 and B4035 at Evesham, Worcestershire | M5 at Whittington, Worcestershire | Previously the A44. There is also a spur named the B4084 between the new A44 at Egdon and the main B4084 near Windmill Hill |
| B4085 | B439 at Bidford-on-Avon, Warwickshire | B4035 at Badsey, Worcestershire | Via Marlcliff, Cleeve Prior, The Littletons and Blackminster |
| B4086 | A422 in Stratford-upon-Avon | B4100 near Warmington | Via Tiddington, Wellesbourne, Compton Verney, Kineton and Edge Hill |
| B4087 | B4086 in Wellesbourne, Warwickshire | A422 and A445 in Leamington Spa, Warwickshire | Via Whitnash, Warwickshire |
| B4088 | A422 and A441 west of Alcester, Warwickshire | A44 north of Evesham, Worcestershire | Via Weethley, Dunnington, Iron Cross, Norton and Harvington. Formerly continuation of A441. Originally ran from Kingsmead to Thelsford, cutting the corner between the B4086 and A429. Now unclassified, as the A429 does the job of the B4088. |
| B4089 | A3400 at Wootton Wawen, Warwickshire | A435 and B4090 at Alcester, Warwickshire | Via Little Alne, Great Alne and Kinwarton |
| B4090 | A38, south of Droitwich | A435, north of Alcester | Occupies former route of A38 in Droitwich. Via Feckenham and Woolmere Green. |
| B4091 | A491, Stoneybridge Island | B4090 at Hanbury | Originally A449, then A491 between Stoneybridge and Stoke Heath. |
| B4092 | A422 at Holberrow Green | A435, south of Studley | Via Astwood Bank and Studley |
| B4093 | B4092 in Studley | Woodrow, Redditch | Originally continued into Redditch town centre. |
| B4094 | A441 | B4091 | Short road in Stoke Heath, known as Worcester Road throughout its length. Originally ran in Redditch; its precise route has not been definitely established as the route never showed up on any maps, but it likely ran along Church Green East. Declassified early on and is now pedestrianized. |
| B4095 (defunct) | B4095 Studley Road, Redditch | A41/A46 in Warwick | Start point later moved to an interchange with the A441 and A448; formerly crossed River Arrow on now dismantled bridge west of the A435 junction (much of original route west of the A435 is now gone). Upgraded to the A4189; several road signs for the B4095 remain in Redditch. |
| B4096 | B4184 in Redditch | A441 near Cofton Park | Originally northern terminus was on the A456 in Halesowen. This became the A459 and is now the B4451. |
| B4097 (defunct) | Banbury Road, Warwick | Smith Street, Warwick | St. Nicholas Church Street; shown on one map as an unnumbered A-road. Now part of the A429 one-way system. |
| B4098 | A51 south of Kingsbury, Warwickshire | Coventry City Centre. | Entire route formerly classified A423 via Nether Whitacre, Furnace End, Over Whitacre, Fillongley, Corley and Coundon. Section from Kingsbury to B4114 (then the A47) later became an extension of the A51. After the A47 was downgraded, the section of A51 beyond Kingsbury was downgraded to the B4098 which ran as far as Coundon on the edge of Coventry. The remaining part of the former A423 was renumbered A4170 into Coventry until the 1980s when the B4098 was extended to Coventry City Centre. Originally ran along Priory Road in Warwick. Now part of the A445 one-way system. |
| B4099 | A445 in western Leamington Spa | A425 in south-eastern Leamington Spa | |

## B4100 to B4199

| Road | From | To | Notes |
| B4100 | Bicester | M40 near Bishop's Tachbrook (and upon reprisal – A441 Digbeth). | Former alignment of A41 prior to the opening of M40. Starts in Bicester near the Bicester Village designer outlet and crosses the A43 near M40 J10. Continues via Baynards Green and Aynho then multiplexes with the A4260 from Adderbury for approximately 3.5 miles. It then regains its status from the Warwick Road, Banbury for less than 1⁄2 a mile as it becomes the A422 briefly. It then fully regains its status as the B4100, near Drayton where it continues for 14 miles passing M40 J12 & J13 at Gaydon and Warwick, respectively. The road is briefly reprised in Birmingham City Centre as a continuation of the A34 until it meets with the B4114 and A47 in Birmingham City Centre. Also used for the section of former A41 from junction with A4540 to A4400 Snow Hill Queensway. |
| B4101 | Coventry City Centre | Redditch Town Centre | Passes through the villages of Balsall Common, Temple Balsall, Knowle, Dorridge, Hockley Heath, Wood End, Holt End and Beoley. Formerly part of the A4023. |
| B4102 | Nuneaton Town Centre | B4101 near Earlswood, West Midlands | |
| B4103 | A452 at Kenilworth | A452 near Kenilworth | |
| B4104 | A452 at Kenilworth | B4103 at Kenilworth | |
| B4105 | A41 Solihull Bypass | Birmingham Airport | Created in 2020, showing on maps that year. On the November 2019 revision OS VectorMap District map it is shown as unclassified. First used along Balsall Street in Balsall Common, connecting the A446 to the B4101. Became a portion of a rerouted A4023, but was downgraded back to the B4101 (not B4105, the B4101 having taken over the new route) in 1986 due to completion of the M42. Next used in 2015 along Broad Street in Coventry. May have been short-lived; little is known about this route. It is listed in a 2015 FoI request response from Coventry Council as well as on other 2011 documents, but it does not appear on a September 2016 revision of the OS VectorMap District map. The route is now unclassified. |
| B4106 | A4114 at Allesley, Coventry | B4101 at Spon End, Coventry | |
| B4107 | A429 at Earlsdon, Coventry | B4098 at Radford, Coventry | Originally ran from A45 Much Park Street to Spon Street in Coventry city center. Upgraded to Class I status by the early 1930s, becoming the A45 mainline (later A4114). Now unclassified. |
| B4108 (defunct) | B4106 Spon Street, Coventry | A423/A444 in Coventry | Declassified due to later redevelopment of Coventry. The section along King Street is now gone, lost under the A4053. |
| B4109 | Coventry City Centre | Hinckley Town Centre | |
| B4110 | B4109 at Hillfields, Coventry | A45/A46 at Willenhall, Coventry | |
| B4111 | B4114 in Hartshill, Nuneaton | Atherstone | Originally B4115, then upgraded to A4135 before assuming current number. Via Mancetter. Originally ran from Binley (near Coventry) to North Kilworth, but was extended in the early 1930s to the southern extension of the A50 (formerly B568, now A5199) at Bosworth Lodge. Around 1935, the original route was upgraded to the A4114 (later A427); the extension hung on for a few more years as the B4111 before being renumbered to the B5414 as it was out-of-zone. The section between Coventry and the A5 was downgraded back to Class II status as the B4027, despite being a duplicate (this was corrected to B4428 in the 2000s). With the impending A14 in the 1990s the eastern section was renumbered to A4303 between the A5 and M1 and A4304 on the section to North Kilworth; both numbers are out-of-zone. |
| B4112 | A426 in Rugby, Warwickshire | B4114 in Church End, Warwickshire | |
| B4113 | A444 in Nuneaton | A452 near Leamington Spa | Originally ran from Bedworth to Bulkington. Now the B4029. |
| B4114 | A34, Birmingham | A5460 at Fosse Shopping Park, Leicestershire | Has two branches in central Birmingham, both follow parts of the former Inner Ring Road. Broken by a section of A47 between A4540 Middleway and Saltley. Connects Birmingham to Coleshill. Except for section of former A4400, entire route formerly part of A47. |
| B4115 | A45 in Finham, Coventry | A46/A429 near Warwick | Originally ran from Atherstone to Nuneaton. Upgraded to Class I status in the 1920s, becoming the A4131, but was downgraded back to Class II in the 1960s and is now the B4111. |
| B4116 | B4098, B4114 at Over Whitacre, Warwickshire | B5006 near Measham, Leicestershire | |
| B4117 | B4118 in Water Orton, Warwickshire | A446, near Coleshill, Warwickshire | |
| B4118 | Castle Bromwich, West Midlands | A446, near Water Orton, Warwickshire | |
| B4119 | B4118 in Castle Bromwich, West Midlands | B4114 in Castle Bromwich | Originally ran from Wishaw to Tamworth. Due to its importance, it was upgraded to Class I status as the A4091 in the early 1920s. |
| B4120 | A38 in Longbridge, Birmingham | A441 near Alvechurch, Worcestershire | |
| B4121 | A4123 at Quinton, Birmingham | A441 at Cotteridge, Birmingham | |
| B4122 | A435 in King's Heath, Birmingham | A4040 in King's Heath | |
| B4123 (defunct) | | | This road ran from the A456 Hagley Road near Birmingham's boundary with Smethwick in Bearwood to a junction with the A441 near King's Norton running via Harborne. It was subsequently replaced by the A4123 south of Harborne and then later by an extended A4030 which also absorbed the A4123 beyond Harborne. During the 1960s, the route became part of the A4040. |
| B4124 | A4540 in Ladywood, Birmingham | A4040 in Harborne, Birmingham | The middle section of the B4124 is now the A4540. |
| B4124 | A41 in Hockley, Birmingham | A34 in Great Barr, Birmingham | |
| B4125 | A456 in Edgbaston, Birmingham | A4030 in Smethwick, West Midlands | Crosses the former Harborne Branch Line, now a footpath. |
| B4126 | A4040 in Winson Green | B4145 near Small Heath, Birmingham | Exists in two sections, connected by the A4540. |
| B4127 | A38 Suffolk Street Queensway in Birmingham | A4540 Islington Row Middleway in Birmingham | Originally started on New Street in City Centre. |
| B4128 | B4100, Digbeth | A4040 near Stechford, Birmingham | Extended to B4100 when A45 diverted onto Small Heath bypass. Originally ran along Suffolk Street in Birmingham. Upgraded to Class I status early on (the current number was in use by 1932), although due to its short length it is unknown what number it received. Later upgraded to a portion of the A4400 Queensway and is now the A38. |
| B4129 | A457 in Cape Hill, Birmingham | A4040 in Harborne, Birmingham | Runs via Metchley Lane, former boundary between Staffordshire and Warwickshire. Originally ran along Navigation Street in Birmingham. Due to its short length, it is not known how long the B4129 number lasted; a map showed the route as Class I, but with no number (it was the A4166). Now unclassified after all traffic was routed out of the center of Birmingham. |
| B4130 (defunct) | | | Linked Bull Ring and Camp Hill in Birmingham as alternative to A41. Ran down Jamaica Row (no longer exists), Cheapside and Ravenhurst Street. Declassified (and partially gone) due to extensive redevelopment in the area. |
| B4131 (defunct) | | | Ran between Digbeth (then the A41) and B4132, Curzon Street via Meriden Street and New Canal Street. Now unclassified. |
| B4132 | A41 in Birmingham | A38(M) at Aston | Originally started on Birmingham High Street which was then the A47. Ran down Curzon Street (where it met the B4131) and Lawley Street. |
| B4133 | A4540 Dartmouth Middleway, Birmingham | A47 in Nechells, Birmingham | May not exist. Formerly started on Inner Ring Road. |
| B4134 (defunct) | | | Ran down Livery Street, Birmingham City Centre. Now unclassified. |
| B4135 | A457 in Smethwick, West Midlands | A4400, Birmingham | Section between A4540 road and A4400 was originally A457. |
| B4136 | A4092 in Smethwick, West Midlands | A41 in Handsworth, Birmingham | Originally ran along Waterloo Road but this was upgraded to the A4092 in 1924. |
| B4137 | A4040 in Witton, Birmingham | A47 in Nechells, Birmingham | Prior to the creation of the A4040, continued to A41 in Handsworth. |
| B4138 | A453 in Perry Barr, Birmingham | A4026 in Little Aston, Staffordshire | Originally continued along College Road to the current A34. |
| B4139 | Six Ways Island, Erdington | A5127 in Erdington | Erdington High Street (original A38). Mostly one way. Due to pedestrianised northern part of High Street, diverted along New Street. Previously used for the section of A453 between Perry Barr and Sutton Coldfield. |
| B4140 | A41 in Hockley, Birmingham | A4040 in Witton, Birmingham | |
| B4141 | B4006 (original A419 in Swindon) | A361 in Swindon | Originally unclassified, it was part of the A345 during the 1970s. A road of the same number originally ran from Salford Circus, Birmingham to a junction with the A446 in Curdworth. When this was upgraded to A road, the B4141 was reused for the previously unclassified road between the A446 junction and A423 near Kingsbury. This was upgraded to A road status too when the A38 Sutton Coldfield bypass opened (although the original route along Old Kingsbury Road has been closed to traffic). |
| B4142 | A5127 in Erdington, Birmingham | A453 in New Oscott, Birmingham | |
| B4143 | A4311 in Swindon | B4006 in Swindon | Gypsy Lane, Swindon Originally ran in Birmingham from the A455 (now A34) New Town Row to the A41 Camp Hill. Upgraded to Class I status, with all except the southern end becoming the A45 by the mid-1940s. Now part of the A4540. |
| B4144 | A41 in Hockley, Birmingham | B4132 in Nechells, Birmingham | |
| B4145 | A41 in Sparkhill, Birmingham | B4114 in Saltley, Birmingham | |
| B4146 | A41 in Tyseley, Birmingham | A435 in King's Heath, Birmingham | |
| B4147 | A4040 in Stechford, Birmingham | B4114 in Hodge Hill, Birmingham | |
| B4148 | A453 in Whitehouse Common, Sutton Coldfield | A38 in East Birmingham; A5127 in Erdington | Two branches south/west of Walmley |
| B4149 | B4166 in Greets Green, West Midlands | A453 in New Oscott, Birmingham | |
| B4150 | A420 Headington Hill | A40 Oxford Northern Bypass | Marston Road and Marsh Lane in Oxford. Originally ran from Queslett to Sutton Park. Upgraded to a portion of the A4041 in the 1970s. |
| B4151 | A4148 in Walsall | A453 near Bassetts Pole, Warwickshire | Terminus is actually in Staffordshire |
| B4152 | A454 in Aldridge, West Midlands | A452 in Brownhills, West Midlands | |
| B4153 | A461 | B4152 | Coppice Road in Walsall Wood. Not signposted. |
| B4154 | A4041 in Pheasey, West Midlands | B5013 in Hednesford, Staffordshire | |
| B4155 | A452 in Brownhills, West Midlands | A5 near Brownhills, in Staffordshire | Prior to 1927, the road started at the junction of Broad Street and Stafford Street in Wolverhampton city centre. Some maps indicate the B4155 ends at the junction with the B5011 although some signs on the ground indicate it continues to the next roundabout where the B4155 (unsigned) turns left to end on the modern A5. The road ahead is now closed and gated but the B4155 originally continued along that road to a junction with the original A5. |
| B4156 | A460 in Fallings Park, Wolverhampton | A34 in Great Wyrley, Staffordshire | Lanes split to form one way system in Cheslyn Hay. |
| B4157 (defunct) | | | Ran from New Road, Willenhall (original A454) to A462 in Ashmore Lake via Lower and Upper Lichfield Street. Later extended to Bilston Lane (A463, then A454, now B4484). Section through and north of Willenhall declassified in 1970s, southern section now B4484. Signs for B5147 (presumably a typo) at Bloxwich Road South junction with A462 in Lane Head, near New Invention were installed as recently as 2012 replacing accident damaged ones. |
| B4158 | Chippenham, junction with A420 | A350 north of Chippenham | This is known as Malmesbury Road in Chippenham. This was previously used for the following roads in Wolverhampton: Garrick Street, Market Street and Princess Street. After Dudley Street (the original route of the A459) was pedestrianized in the 1960s, these streets formed a rerouted A459 until all roads in the city centre were declassified in 1986 due to completion of the Inner Ring Road. Another B4158 appeared in Dudley on OS maps between the 1950s and 1970s. Perhaps due to the duplicate number, it was renumbered to B4588. |
| B4159 (defunct) | | | This was used for the northern half of School Street Wolverhampton until the southern section opened in the 1960s. Prior to then the A449 had run along Worcester Street and Victoria Street in the town centre. Upon the opening of the southern part of School Street, the roads exchanged designation with Victoria Street becoming the B4159 instead. In common with all roads in the city centre, Victoria Street was declassified in 1986 due to completion of the Inner Ring Road and work was carried out in 2022 and 2023 to pedestrianize the street. |
| B4160 | | | Redditch Ring Road. One-way throughout its length. A road of the same number ran down Lower Stafford Street (between Cannock Road and Stafford Road) in Wolverhampton until the 1960s but is now part of the A449. |
| B4161 | A4039 in Blakenhall, Wolverhampton | A41 near Tettenhall | via Compton and Penn |
| B4162 | A41 in Bilston | A4039 in Bilston. | Previously also met A463 at A4039 junction prior to opening of Black Country Route (A463/A454). This was part of the London-Holyhead coaching route prior to the opening of Wellington Road as part of Thomas Telford's improvement work. This route number was briefly allocated to the current A4126. |
| B4163 | A41 in Bilston | A461 in Dudley Port, Sandwell | via Coseley (Daisy Bank) |
| B4164 | A40 in Whitchurch | Symonds Yat East | Originally ran from Moxley to Gospel Hill. Renumbered to the A4098 in 1924. |
| B4165 (defunct) | | | Connected West Bromwich and Walsall town centres. Now the A4031. |
| B4166 | A461 near Great Bridge, West Midlands | A4034 near Oldbury, West Midlands | Originally ran between West Bromwich Street (former A4035), Great Bridge and A4034 in Oldbury town centre. |
| B4167 | B4124 in Hamstead, Birmingham | A4041 in Great Barr, West Midlands | |
| B4168 (defunct) | | | Ran down Roebuck Lane and Galton Bridge between Smethwick and West Bromwich. Galton Bridge is now closed to traffic while Roebuck Lane was severed by the M5. |
| B4169 | Smethwick Town Centre, West Midlands | A4034 in Blackheath, West Midlands | Divides into two branches, each joining A4034 north and south of Blackheath |
| B4170 | A457 in Oldbury, West Midlands | B4169 in Langley Green, West Midlands | |
| B4171 | A459 Dudley, West Midlands | Blackheath, West Midlands | Extended via former route of A461 Trindle Hill to meet A459 when bypass opened. |
| B4172 | A461 in Brierley Hill | A4100 in Brierley Hill | Prior to 1925 continued to Cradley Heath along current route of A4100. |
| B4173 | A459 in Netherton, West Midlands | A458 in Cradley | |
| B4174 | A4100 in Quarry Bank, West Midlands | A458 in Cradley | |
| B4175 | A449 in Wall Heath | A459 in Upper Gornal, Dudley | via Gornal Wood |
| B4176 | B4177 in Dudley | A442 south of Telford | Forms part of one way system with B4177 in Dudley. |
| B4177 | B4171 in Dudley | A459/A461 junction in Blowers Green, Dudley | King Street was part of A461 until Dudley Southern Bypass opened. Blowers Green Road part of A459 until bypass opened. Between 1922 and 1925, this was allocated to the current A4101 between the A461 and A449 (then A4040) junctions. |
| B4178 | A449 in Wall Heath | A4101 west of Kingswinford Town Centre | Called Swindon Road along its entirety and runs for approximately half a mile |
| B4179 | A4101 in Pensnett, West Midlands | A461 in Brierley Hill Town Centre | Previously continued along Tansey Green Road to B4175 Stallings Lane. |
| B4180 | A491 in Wordsley, West Midlands | A461 in Brierley Hill | Eastern section of Brockmoor High Street is one way, traffic redirected along Hickman Road |
| B4181 | A4061 in Bridgend | Coychurch roundabout (A473) | Former routing of the A473. Originally used on a route connecting the A461 to the A449 (now A491) in Amblecote. Upgraded to Class I status, becoming the A4102 in 1925. |
| B4182 | A456 in Bearwood, West Midlands | B4170 in Langley Green, West Midlands | |
| B4183 | Halesowen Town Centre, West Midlands | A456 in Hayley Green, West Midlands | Formerly route of A456 until Halesowen by-pass opened. |
| B4184 | A441 in Redditch | A448 in Bromsgrove Town Centre | Largely follows the former route of the A448. Originally ran along Chapel Street in Lye, cutting the corner between the A58 and A4036. Declassified after the 1960s. |
| B4185 | B4091 (former A449) in Catshill, Worcestershire | A38 near Lydiate Ash, Worcestershire | |
| B4186 | A458 in Wollaston, West Midlands | A4036 just south of Lye | Previously used for St John Street in Bromsgrove which is now part of the A448 and B4184. |
| B4187 | A491 in Stourbridge | A456 in Hagley, Worcestershire | This originally ran from the A450 to the A456 along Park Road. When the A450 through West Hagley was downgraded, this became the B4187 too. The old route remains as a spur of the B4187. |
| B4188 | A491 near Belbroughton, Worcestershire | A456 in Blakedown, Worcestershire | |
| B4189 | A449 near Kidderminster, Worcestershire | A442 near Kidderminster, Worcestershire | Bridges the River Severn north of Kidderminster |
| B4190 | B4189 near Kidderminster, Worcestershire | A456 near Bewdley, Worcestershire | Crosses the River Severn at Bewdley |
| B4191 (defunct) | | | Ran along Oxford Street and Worcester Street in Kidderminster. Mostly pedestrianised it was at one time part of the A451 one-way system. |
| B4192 | A419 at Commonhead, near M4 on east edge of Swindon, Wiltshire | A4 in Hungerford, Berkshire | Formerly part of the A419 until the M4 was built. Previously used for the road from Bromsgrove to Kidderminster, now part of the A442. |
| B4193 | A449 near Hartlebury, Worcestershire | A4025 at Stourport, Worcestershire | |
| B4194 | B4196 at Areley Kings, Worcestershire | B4363 near Kinlet, Shropshire | Goes through Bewdley |
| B4195 | B4190 at Bewdley, Worcestershire | A451 at Stourport, Worcestershire | |
| B4196 | A451 at Areley Kings, Worcestershire | A443 at Holt Heath, Worcestershire | |
| B4197 | A443 at Great Witley, Worcestershire | A44 at Knightwick, Worcestershire | Originally ran from Droitwich to Holt Heath. Upgraded to the A4133 in the late 1920s. |
| B4198 (defunct) | A38 Worcester Road, Droitwich | B4192 High Street, Droitwich | Ran along St Andrew's Road; now unclassified. |
| B4199 | B4194 near Kinlet, Shropshire | B4363 near Kinlet, Shropshire | 1 mile long |

## B4200 to B4299

| Road | From | To | Notes |
| B4200 | Wednesbury, West Midlands | A4038 near Darlaston, West Midlands | Previously continued to A462 in Darlaston Green. Originally (1922–1927) the route number for the A4117 in Shropshire |
| B4201 | A4117 near Cleobury Mortimer, Shropshire | B4363 near Cleobury Mortimer, Shropshire | Passes Lakeside Country Park. |
| B4202 | A443 at Abberley, Worcestershire | A4117 near Cleobury Mortimer, Shropshire | via Abberley and Bayton Common. |
| B4203 | A443 at Great Witley, Worcestershire | A44 at Bromyard, Herefordshire | via Stanford-on-Teme and Upper Sapey |
| B4204 | A443 at Worcester | A4112 at Tenbury Wells, Worcestershire | via Lower Broadheath (birthplace of Sir Edward Elgar) |
| B4205 | A44 gyratory, Worcester | A44 London Road | This road runs through Worcester city centre. Passes Worcester Shrub Hill. |
| B4206 | A443 at Worcester | A449 at Worcester | Malvern Road was the route of the A48 until the 1920s. |
| B4207 (defunct) | | | Now the B4312, it formed a bypass for the A40 through Carmarthen prior to the opening of the A40 bypass. A previous B4207 now forms the A4103 in Worcestershire. |
| B4208 | B4213 at Staunton | A449 at Newland, Worcestershire | via Pendock and Barnard's Green |
| B4209 | A449 at Malvern Wells | B4211 (former A440) at Hanley Castle | passes Three Counties Showground. |
| B4210 | Walsall, West Midlands | A462 near Essington, Staffordshire | The section between Bloxwich and Walsall was originally the A34. They swapped numbers about 1987. Originally ran from Little Malvern to Upton-upon-Severn. Upgraded to the A4104 before 1930. |
| B4211 | A449 at Malvern | A417 between Corse and Hartpury, Gloucestershire | The road originally ended on the A4104 but was later extended along the course of the A440 to Barnard's Green and later still along the remaining former A440 (which had become the A4532) to Malvern. |
| B4212 (defunct) | A38 at The Grove | A440 (now A4104) at Holly Grove | Declassified after the 1990s. Now just an access road. |
| B4214 | A438 at Ledbury, Herefordshire | A4117 at Cleehill, Shropshire | 28 miles long. Originally continued along current route of A417 to A40 near Gloucester. |
| B4215 | A449, Preston Cross Roundabout | A40, near Hynam | Originally started at Hope under Dinmore on A49 and followed course of current A417/A4172. |
| B4216 | A438/A449 in Ledbury | A40 in Huntley | Concurrent with B4215 between Dymock and Newent |
| B4217 | Five Ways, Birmingham | A4040 Fox Hollies Road at Acocks Green, Birmingham | Route of the number 1 bus. Via Edgbaston and Moseley. A road of the same number passed through Wyche Pass in Malvern but was upgraded to the A4105 in the 1920s. Part of it became the B4218 in the 1960s, the rest unclassified. |
| B4218 | A449 in Malvern | A449, West of Malvern Hills | This road partly follows the earlier route of the B4217 but is diverted in the area of Fossil Bank. Via Colwall Green and Upper Colwall. Route was A4105 between the 1920s and 1960s. Originally ran from Bosbury to Stony Cross. Renumbered to a portion of the A4154 after World War II, but downgraded soon after to the B4220 (the B4218 number was already in use elsewhere). |
| B4219 | A4103 at Storridge | B4232 in Malvern | Marked unsuitable for HGVs due to narrow width of road. |
| B4220 | B4214 in Bosbury | A44, near Bromyard | via Pow Green, Westfield and Stony Cross. Section between A4103 and Bosbury briefly upgraded to A4154 (which continued to the A438, north of Ledbury. |
| B4221 | B4215 at Newent | A40 at Ross-on-Wye | Includes link to T-junction with M50 at J3. |
| B4222 | B4224, south of Lea | B4221 in Kilcot | via Aston Crews and Aston Ingham |
| B4223 | A4058 at Llwynypia | A4061 near Treorchy | via Ton Pentre Originally ran from Monmouth to Huntley; was the lowest numbered Class II road in Wales. Due to its importance, it was upgraded to Class I status early on, becoming the A4136 in the late 1920s. |
| B4224 | A438 at Hereford | A4136 at Mitcheldean | via Hampton Bishop, Mordiford and north Mitcheldean |
| B4225 | A449 at Old Gore | B4224 at Old Gore | Very short road to be used to cut the Old Gore Crossroads and Give Way traffic. |
| B4226 | A4151 at Cinderford | B4028 at Coleford | via Forest of Dean Originally ran from Cinderford to Elton. Renumbered as a portion of the A4151 in 1935. |
| B4227 | B4226 at Cinderford | A4151 at Cinderford | Originally started on the current A48, which was numbered A437 at the time, in Blakeney and ended on the A40 in Ross-on-Wye town centre. |
| B4228 | A48 near Chepstow | A4136 near Coleford | At one time, the southern terminus was at the Aust Ferry. Also ran to Ross-on-Wye. |
| B4229 | A4137 at A40 | B4234 near Goodrich | passes former Flanesford Priory |
| B4230 | A438 near Byford | A4112 near Weobley | By way of Mansell Gamage, Norton Canon and Weobley Originally ran from Old Forge to Harewood End. Upgraded to Class I status as the A4137 in the late 1920s. |
| B4231 | B4228 in Trow Green | former A48 in Lydney | via Bream. Originally started on A466 near Monmouth |
| B4232 | A449 below Herefordshire Beacon | A449 near Link Top | Runs around the Western side of the Malvern Hills. Originally ran from Monmouth to King's Thorn. Renumbered as an extension of the A466 in the mid-1920s. |
| B4233 | Abergavenny | Monmouth | By way of Llanvapley and Rockfield |
| B4234 | A40/A449 near Ross-on-Wye | B4231 in Lydney | via Forest of Dean. Hill Street in Lydney was once part of the A48. (Still signed as such.) Originally ran from Raglan to Llanvihangel Gobion. Became a portion of a rerouted A40 in 1935 (old A40 became the B4251). |
| B4325 | A472, east of Usk | A466 road, Chepstow bypass | Originally started in Usk town centre on A449 (originally A48). Replaced by A472 when bypass opened. Via Slough |
| B4236 | A4042 near Llanrafon | B4237 (former A48) | via Caerleon. The section through Caerleon was originally the A48. |
| B4237 | A48 at Newport | A48 at Newport (M4 J24) | Now part of the former A48 route through Newport. The previous route, including Newport Transporter Bridge is now unclassified. |
| B4238 (defunct) | | | Short road in Newport City centre: Emlyn Street (now Emlyn Walk) and Dock Street. Now largely pedestrianised. |
| B4239 | B4487 in Rumney, Cardiff | A48 in Duffryn, Newport | via Peterstone Wentlooge. At one time it crossed the Newport Transporter Bridge before being replaced by the B4237. |
| B4240 | B4237, Cardiff Road, Newport | B4591, Caerau Crescent in Newport | Stow Park Avenue |
| B4241 (defunct) | Harlequin Roundabout, A4042 | B4591 (former A467) in Newport | Declassified in the 2000s. |
| B4242 | A4109 at Aberdulais | Pontneddfechan | Mostly follows the former route of the Heads of the Valley Road (A465). |
| B4243 (defunct) | A467 in Bassaleg | A468 in Rogerstone | Renumbered to A4072 (now A467) in 1935. |
| B4243 (defunct) | | | Ran along Lleyncelyn Road, North Road and Porth Street in Porth; now part of the B4278 one-way system. The route is shown as an A-road in the early 1970s, so the number was probably assigned after the completion of the A4058 bypass. Although no maps have been found showing the B5243 number, it is possible that the number was briefly assigned before the renumbering to the B4278. |
| B4244 (defunct) | A472 in Pontypool | A4042 in Llantarnam | Upgraded to Class I status as the A4051 in the 1960s, but later road network improvements in Cwnbran led to the route being bypassed and was then declassified. |
| B4245 | A48 at Llandevaud | A48 at Caldicot | via Llanmartin and Magor. A road of the same number previously ran from Little Mill, near Pontypool to Abergavenny. It was upgraded to A4125 and now forms part of the A4042. |
| B4246 | A4043 at Abersychan | A465 at Govilon A465 at Llanfoist | By way of Blaenavon |
| B4247 | Rhossili | A4118 in Scurlage | via Pitton. Originally ran from Blaenavon to Govillion as the northern continuation of the A4043. Renumbered as a portion of a northern extension of the B4246 in 1935. |
| B4248 | B4246 near Blaenavon | A467 at Brynmawr | via Llanelly Hill |
| B4251 | A467 in Portllanfraith | A467 in Wattsville | The two spurs off the main route in Portllanfraith were originally the A472 and A4048, the latter being the original northern route of the B4251 before the Blackwood bypass opened. |
| B4252 | A469 in Pengam | A472 south of Hengoed | via Fleur-de-lys |
| B4253 (defunct) | A4048 in Blackwood | A4049 in Pengam | Cefn Road, Twynyffald Road and Fair View; became part of B4254 and is now unclassified. |
| B4253 (defunct) | A4055 | A4160 | Exact line is contradicted by map makers but may have followed Barry Road |
| B4254 | A4054 in Edwardsville | A4048, east of Blackwood | connects the Taf and Sirhowy valleys. Via Gelligaer |
| B4255 | High Street, Bedlinog | A472 south of Nelson. | The two arms south of Nelson were historically the A472. Via Trelewis |
| B4256 | A4048 in Tredegar | B4257 in Rhymney | a spur of the B4257 in Rhymney allows to access the southbound B4257 |
| B4257 | A469 in Pontlottyn | A465/A469 near Lechrydd | The Rhymney bypass partly occupies the former northern section of the road. Mostly follows the former route of the A469. Passes through Rhymney town centre. |
| B4258 (defunct) | | | The number was used for the gap in the A4055 between Grangetown and Llandough, which was a toll road, until 1935. The A4055 was then extended along the majority of the B4258 leaving just a short section between Canton and Llandaff which was later declassified. The A4055 later became the B4267. An earlier B4258 ran via Albany Road and is now part of the A469. |
| B4259 (defunct) | | | Ran from Butetown (A470) to A48 across the river from Cardiff Castle. Now the A4119, it ran via Grangetown. |
| B4260 | A40 near Bridstow | A40 near Hildersley, Ross-on-Wye | Former route of A40 in Ross-on-Wye Originally ran from Llandough to Penarth; was not connected to the rest of the UK classified network until 1935, when it was renumbered to A4160. |
| B4261 | A469 at Cardiff | A4161 at Cardiff | Road Name: City Road Originally ran from Llandaff to Llantrisant. Became the A4119 by the mid-1920s. |
| B4262 | A4119 south of Radyr | A470 near Tongwynlais | Follows part of the course of the River Taff. |
| B4263 | High Street in Senghenydd | A469 at Caerphilly Common | Passes Caerphilly Castle. |
| B4264 | A4222 in Pontyclun | A4119 east of Miskin | via Miskin. Originally ran in Caerphilly from the B4263 in Penyrheol to the A468 (now B4600). Renumbered as a spur of the B4263 in 1935. |
| B4265 | A4226 near Cardiff International Airport | A473 at Bridgend | via Llantwit Major. Originally started in Llantwit Major and ran to Cardiff International Airport and Barry. |
| B4266 | A4226 at Weycock Cross | A4050 at Barry | Road name: Pontypridd Road. |
| B4267 | A4119 at Canton | A4055 and A4231 at Ty Verlon Industrial Estate | via Llandough Originally ran from Llantwit Major to Cowbridge. Renumbered as a southern extension of the B4270 in 1935. |
| B4268 | B4270 at Llandow | A48 at Pentre Meyrick | |
| B4269 | A4042 at Llanellen | B4246 at Llanfoist | 7.5 tonne weight limit throughout most of route. Originally ran from Bridgend to Llantwit Major. Renumbered as a western extension of the B4265 in 1935. |
| B4270 | B4265 North of Llantwit Major | A4222 at Cowbridge | passes former RAF Llandow |
| B4271 | A4118 near Upper Killay | B4295 at Llanrhidian | via Pengwern Common Originally ran from Ystrad Rhondda to Llantrisant. The section from Ystrad to Tonyrefail was upgraded to the A4093 in 1924, but a year or so later, the entire route was upgraded to the A4119. Much of route now unclassified or part of the B4278. |
| B4272 (defunct) | | | Now part of the B4595. Connected A473 and A4058 near Treforest. |
| B4273 | north of Ynsybwl | A4223 in Pontypridd | Originally started in centre of Ynsybwl |
| B4274 (defunct) | | | Ran from junction with B4273 in Pontypridd to A470 in Pont Sion Norton. Bridge over River Taff now A4223, most of the remaining part replaced by A470 dual carriageway. |
| B4275 | A4054 at Abercynon | A4059 at Penywaun | Originally the A4059 route. Via Mountain Ash. |
| B4276 | B4275 (former A4059) at Trecynon | A465 north of Llydcoed | |
| B4277 (defunct) | | | Ran from Aberdare via Porth and Tonyrefail in the Cynon Valley. Most of route upgraded to A4233 in the 1980s |
| B4278 | A4093 near Gilfach Goch | A4058 near Dinas | This road originally ran through Dinas and Tonypandy but was upgraded to the A4058 route. |
| B4278 | A4058 near Porth | A4233 near Stanleytown A4058 near Llwynypia | This road was originally the A4233 and A4058 but following the completion of the Porth Relief road these roads were downgraded. |
| B4279 (defunct) | | | There have been two roads with this number: a short lived B4279 ran between Bridgend and Swansea which was upgraded to the A4093 in 1924 and a B4279 in Wiltshire. This now unclassified route connected the A420 (now the B4069) at Langley Burrell to the A420 east of Sutton Benger. |
| B4280 | A473 near Pencoed | A4061 at Bryncethin | via Hirwaun Common |
| B4281 | A48 at Pyle, near Bridgend | A4063 near Aberkenfig | via Cefn Cribwr |
| B4282 | A4017 at Cwmafan | A4063 at Cwmfelin | via Maesteg. A previous B4282 forms part of the current A4106 in Porthcawl. |
| B4283 | A48 near Groes, Port Talbot | A4229 at South Cornelly | via Kenfig Burrows. Part of former route now the A4229 |
| B4284 | Five Ways, Birmingham | B4124 in Edgbaston, Birmingham | one way in an eastern direction only. Called Harborne Road. A previous B4284 was a dead end route starting at Cymer in South Wales but was upgraded to the A4107 and extended to Rhondda in 1925. |
| B4285 | A4054 at Troed-y-rhiw | A4054 near Merthyr Tydfil | Passes close to site of Aberfan tragedy when 116 mostly children lost their lives. Old route passed through Aberfan village centre. First used between Cymer and Glyncorrwg. Upgraded to the A4108 in 1925, then renumbered as the northern end of the A4063 in 1935. Now unclassified. Next used from Crynant to Banwen as a continuation of the new A4109. Became a portion of an extended A4109 by 1932. |
| B4286 | A4241 at Port Talbot | B4287 at Pontrhydyfen | Originally started at Port Talbot docks. |
| B4287 | B4434 at Neath | A4107 at Pontrhydyfen | via Efail-fach |
| B4288 (defunct) | A48 in Neath | A465 (now A4109) in Aberdulais | It is not known how long this B4288 lasted, but it does not appear on any maps after the 1920s. Now part of the B4434. |
| B4288 (defunct) | A48 at St. Mellons | A468 at Bassaleg | Much of route now unclassified except a 700-yard section that is part of the B4562. |
| B4289 | A3102 & A4289 in Swindon | A4361 in Swindon | Part of Swindon ring road. An earlier B4289 existed in Neath, was later upgraded as part of the A48 one-way system and is now partly numbered B4434. |
| B4290 | B4489 at Swansea railway station | A4067 at Victoria Park | Originally one continuous route, the two sections of B4290 are separated by four miles of the A4067 road. |
| B4290 | A483 near Jersey Marine | A4230 at Neath Abbey | |
| B4291 | A48/A4230 near Peniel Green | B4603 at Clydach | via Glais and Birchgrove |
| B4292 (defunct) | | | Ran from St Thomas in Swansea to Llansamlet. Later upgraded to A4217, it was partly downgraded again during the 1970s but numbered B5444 despite being still in use for a road in Flint. |
| B4293 | A466 in Monmouth | A466 in Chepstow | via Trellech and Chepstow Park Wood Originally ran along Oystermouth Road and Victoria Road near the Swansea seafront. Later became the start of the B4290 and is now part of the A4067. |
| B4294 | A4055 in Barry | A4055 in Barry | The former route of the A4055 through Barry town centre Originally ran from Swansea to Port Eynon along the Gomer Peninsula. Upgraded to Class I status in the mid-1920s, becoming the A4118. |
| B4295 | A4216 at Cockett | B4271 at Llanrhidian | north Gower road |
| B4296 | A4118 at Killay | A48 at Pontarddulais | via Gowerton and Dunvant |
| B4297 | A484 near Bynea | A40, south of Court Henry | via Dryslwyn, Gorslas, and Penygroes Originally ran from Ystalyfera to Sennybridge. Renumbered to the A4067 and A4068 in 1935; one section is now the B4599. |
| B4298 | A40 west of Carmarthen | B4299 at Meidrim | Originally ran from Ystalyfera to Gurnos. Renumbered as a northern extension of the A4067 in 1935, but due to upgrades in the area much of the route is now the B4599. |
| B4299 | A4066 at St Clears | B4333 south of Newcastle Emlyn | by way of Trelech Originally ran from Gurnos to Brynamman. Upgraded to Class I status in 1935, becoming the A4068. |

## B4300 to B4399

| Road | From | To | Notes |
| B4300 | A40 near Carmarthen | A476 West of Ffairfach | via Capel Dewi and Llanarthne |
| B4301 | A484 at Bronwydd | A485 at Pontarsais | passes Gwili Steam Railway. Route of the A485 until 1935. |
| B4302 | A483 near Llandeilo | A462 near Crugybar | Passes ruins of abbey in Talley |
| B4303 | A476 near Felinfoel | B4297 near Penceiliogi | passes Prince Philip Hospital |
| B4304 | A484/A4138 at Parc Trostre | A484 in Sandy, west Llanelli | |
| B4304 | A484 in central Llanelli | B4304 at Morfa | Some maps omit this route. |
| B4304 | Llanelli town centre | B4304 at Machynys | This branch is part of the original alignment of the B4304 which started on the then A48 and ran via Park Street (now pedestrianised) and Stepney Street. |
| B4305 (defunct) | | | Short link road between B4304 Station Road and A48 (later A484) Swansea Road. Partly replaced by the A4214. |
| B4306 | A4138 in Hendy | B4309 near Bancycapel | via Llanon, Bryndu and Pontyberem Originally ran along Market Street in Llanelli; too short (only 100 yards) to appear on maps and may have never appeared on any maps at all as it was decommissioned by 1935. Th route was still Class II in the 1960s, but as a spur of the B4304. The original southern end is now gone, lost under Argos. |
| B4307 (defunct) | | | Ran down Vaughan Street in Llanelli; too short (one block long) to appear on maps. Unclassified by the 1960s and is now pedestrianized. |
| B4308 | B4309 at Llanelli | A484 near Kidwelly | via Trimsaran. Former route of A484 in Kidwelly also part of B4308 (not signed). |
| B4309 | A4124 in central Llanelli | A484 near Cwmffrwd | via Pontantwn. Previously terminated on A484 in Llanelli but extended to Church Street in Llanelli. |
| B4310 | A476 in Tumble | B4437 at Llansawel | via Drefach, Porthyrryd, Nantgaredig. The spur in Porthyrryd was part of the A48. Passes National Botanical Gardens. |
| B4311 | A484 at Pembrey | A484 by New Lodge | via Burry Port. Originally ran via Church Road in Burry Port but this is now unclassified. |
| B4312 | Llansteffan High Street | A4242 north of Carmarthen | The two arms of the B4312 north of Carmarthen are the original route of the A40 before the bypass opened. The right hand arm passes an obelisk in memory of Lieutenant General Sir Thomas Picton who died at Waterloo. |
| B4313 | A487 in Fishguard, Pembrokeshire | Narberth, Pembrokeshire | Starts at Main St, Fishguard (A487), winds generally S or SE finishing in Narberth (junction with B4314), via Gwaun Valley, Llanychaer, crosses B4329 at Greenway, Rosebush, Maenclochog, crosses A40; approximately 21 miles. |
| B4314 | A4066 in Pendine | A40 at Robeston Wathen | via Red Roses and Princes Gate. A spur leads into Narberth Town centre ending on the A478. |
| B4315 | A478 at Templeton | B4314 at Princes Gate | Originally started on A4075 at Cross Hands and ended at Templeton. This entire stretch is now the A4115. |
| B4316 | A478 at Pentlepoir | A478 near Tenby | Serves Saundersfoot. The route through New Hedges was originally part of the A478. |
| B4317 | A484 north of Pembrey | B4310 at Cwm mawr | via Carway and Pontyberem. |
| B4318 | A477 on Sageston bypass | A478 in Tenby | Originally started in centre of Sageston village. Due to St John's Hill in Tenby being one-way, traffic heading the other way has to use Greenhill Road. |
| B4319 | B4320 on Castlemartin Peninsula | A4319 in Pembroke | via Castlemartin, St Petrox and Kingsfold. When route past live firing range closed (near Castlemartin), diversion runs via Merrion. |
| B4320 | Angle, Pembrokeshire | A4139, at Pembroke Castle | via Hundleton and Monkton, south Pembroke |
| B4321 | Llangrannog, car park | A487 at Pentregat | Single track road for most of its length, barely a car width in places. |
| B4322 | A4139, West Llanon, Pembroke | A4139, north of Pembroke | road names: Water Street, Bush Road, Pembroke Street, High Street, Bellevue Terrace in Pembroke Dock. |
| B4323 (defunct) | | | Short road in Pembroke Dock starting on Fort Road and continuing to then A477 (now A4189) via Laws Street and Bush Street. Bush Street now B4322, rest declassified. |
| B4324 (defunct) | | | Ran from A4076 in Johnson to Neyland where a ferry crossed the river to reach the A477. The B4324 subsequently was upgraded to form part of the A477. When the road bridge opened carrying the A477, the ferry ceased and the southernmost part became an extension of the B4325. |
| B4325 | A4076 north of Milford Haven | A477 N of Neyland | via Waterston and Scoveston Fort. The section through Neyland from the Quay to the current A477 was originally the B4324 and was later upgraded to the A477 (which used a ferry to cross the river). When the road bridge opened, the former B4324 became part of the B4325. |
| B4326 | A4076 | A4076 | Charles Street in Milford Haven. One way for most of its length. |
| B4327 | A487 in Haverfordwest | Dale, west of Milford Haven | |
| B4328 | A40, bypass north of Whitland | B4314 at Tavernspite | via Whitland. |
| B4329 | A487 W of Eglwyswrw | A40 at Haverfordwest | Crosses Preseli Mountains N to S, reaching 404 metres (1,325 ft); scenic views across south and west Wales |
| B4330 | A487 in Haverfordwest | A487 at Croes-goch | Joins W-bound A487 to NE-bound A487 |
| B4331 | A40 at Letterston | A487 at Mathry | part of the B4330 until 1935 |
| B4332 | A487 at Eglwyswrw, Pembrokeshire | A484 at Cenarth, Carmarthenshire | Via Newchapel (Manordeifi) and Boncath; crosses A478 near Blaenffos |
| B4333 | A487 at Aberporth Airport | A484 at Cynwyl Elfed | Via Aberporth, Beulah, Cwm-cou (Carmarthenshire) and Newcastle Emlyn |
| B4334 | B4321 in Llangrannog | A484 near Henllan | via Brynhoffnant and Pengallt |
| B4335 | A484 at Pen-ffynon | A486 at Pentre-cwrt | follows course of River Teifi |
| B4336 | A486 on Llandysul bypass | A485 in Llanllwni | previously met A486 near the old Teifi bridge. This became part of the B4624 with the B4336 running along a new road. Via Penlan. |
| B4337 | A487 at Llanrhystud, Ceredigion | B4302 near Llansawel, Carmarthenshire | via Trelifan and Llansawel |
| B4338 | B4337 at Llanbyder | A486 at the Synod Inn | Originally continued to New Quay where it met the B4339 head on and started at Synod Inn. |
| B4339 | A482 in Ciliau Aeron | B4342 in Dihewyd | Originally ran from the then-B4338 in New Quay to the B4340 (now A482) in Ystrad Aeron. Became a western extension of the B4342 in 1935. |
| B4340 | A4120 in Aberystwyth | B4343 at Pontrhyfdfendigaid | via New Cross and Abermagwr. A previous B4340 now forms part of the A482 between Aberaeron and Lampeter. |
| B4341 | road junction at Galleon Inn in Broad Haven | B4327 in Albert Town | via Broadway |
| B4342 | A486 in New Quay | A485 at Trefercel | via Ystrad Aeron and Stags Head |
| B4343 | A44 below Bryn Glas | A482 at Cwmann | Multiplexes with A4120 between Tyn-y-fford and Devil's Bridge. |
| B4344 | A483 at Llandovery | A40 at Llandovery | Stone Street, Llandovery |
| B4345 (defunct) | | | Mill Street in Aberystwyth. Now part of a rerouted A487. Also appears in the circa 2002 DfT Card Index as "Reserved for Gwndwn goyn - Parcllyn Road" This is generally assumed to be a route from Park Avenue to Parc Y Llyn in Aberystwyth, but for some reason never used. |
| B4346 | A487, Trefachan Bridge in Aberystwyth | A487, North Parade in Aberystwyth | runs along sea front in Aberystwyth |
| B4347 | Vowchurch in Herefordshire | B4233 in Rockfield | via Abbey Dore, Pontrilas, Kentchurch, Newcastle. Prior to 1922 only ran from Vowchurch to A465 at Pontrilas. |
| B4348 | B4350 at Hay-on-Wye, Brecknockshire | A49 near Llandinabo, Herefordshire | via Dorstone, Peterchurch, Thruxton and Turkey Tump. |
| B4349 | B4348 at Webton | A465 near Belmont Abbey | |
| B4350 | A470 north of Llyswen | A438 west of Whitney-on-Wye | via Hay-on-Wye. The road through Hay-on-Wye was the A438 until the 1960s when it swapped route with the B4350 which used the current A438 route. This meant that traffic on the A438 avoided the Whitney Bridge which is a toll bridge with a weight limit. |
| B4351 | A438 at Clyro | B4350 in Hay-on-Wye | |
| B4352 | B4348, north-east of Hay-on-Wye | B4349 at Clehonger | via Pen-y-Park, Bredwardinen, Blakemere. |
| B4353 | A487 at Rhydypeannau | A487 east of Llancynfellin | via Borth |
| B4354 | A497 west of Llanystumdwy | A497 near Pwllheli | This almost dead straight road (along with the nearby current B4112) was built in 1800 during competition for carrying the mailcoaches between London and Dublin. In parts a very narrow road. |
| B4355 | A483 at Dolfor | A44 Kington bypass | via Knucklas, Knighton, Presteigne. Follows English/Welsh border for 15 miles before entering Wales. |
| B4356 | B4362 at Presteigne, Powys | A483 at Llanbister, Powys | The section of B4356 through Presteigne town centre is not signed and traffic is expected to use the parallel B4355 bypass instead. |
| B4357 | A44 near Kington, Herefordshire | B4355 near Knighton, Powys | via Beggar's Bush |
| B4358 | A483 at Beulah, Powys | A4081 near Llandrindod Wells, Powys | until 1995 ran through Beulah village and weight-restricted bridge. |
| B4359 | A49, Edgar Street in Hereford | A438, New Market Street in Hereford | via Widemarsh Street. Former route of A49. A road of the same number now forms parts of the A4113, B4362 and B4355 in Radnorshire. |
| B4360 | B4529 (former A44), west of Leominster, Herefordshire | A4110 in Kingland, Herefordshire | via Cobnash |
| B4361 | A49 at Ludlow, Shropshire | A49 at Leominster, Herefordshire | |
| B4362 | A49/A456 at Brimfield, Herefordshire | A44 near Kington, Herefordshire | |
| B4363 | A454 at Bridgnorth, Shropshire | A4117 at Cleobury Mortimer, Shropshire | |
| B4364 | Bridgnorth, Shropshire | A4117 near Ludlow, Shropshire | |
| B4365 | A49 at Ludlow, Shropshire | B4368 at Corfton, Shropshire | Crosses over the tracks of Ludlow Racecourse – traffic is stopped when course is in use |
| B4366 | A4086 at Caernarfon | A4244 / B4547 | |
| B4367 | B4368 near Craven Arms, Shropshire | A4113 at Bucknell, Shropshire | |
| B4368 | A458 near Bridgnorth, Shropshire | A483 at Abermule, Powys | Crosses A49 (at Craven Arms), A488 and A489 |
| B4369 | B4367 at Broome, Shropshire | B4368 at Aston on Clun, Shropshire | 0.5 miles long |
| B4370 | A49 at Marshbrook, Shropshire | A489 at Horderley, Shropshire | The northern section from Little Stretton to All Stretton was renumbered to B5477 in 2004 |
| B4371 | A458 at Much Wenlock, Shropshire | B5477 in Church Stretton town centre, Shropshire | Intersects with the A49 at Church Stretton |
| B4372 | A44 at New Radnor, Powys | B4357 | |
| B4373 | B5060 at Donnington, Telford, Shropshire | Bridgnorth, Shropshire | Goes through Ironbridge Gorge |
| B4374 (defunct) | B4373 Northgate, Bridgnorth | A458 Salop Street, Bridgnorth | Now part of the B4364 and mostly one-way eastbound. |
| B4375 | B4373 at Broseley, Shropshire | B4376 near Much Wenlock, Shropshire | |
| B4376 | B4373 at Broseley, Shropshire | A458 at Much Wenlock, Shropshire | |
| B4377 (defunct) | B4380 in Ironbridge, Telford | B4373 in Broseley | Renumbered as an extension of the B4373 in 1935. The northernmost section at the Iron Bridge is now unclassified. |
| B4378 | A458 at Much Wenlock, Shropshire | B4368 at Shipton, Shropshire | |
| B4379 | A442 and B4176 at Sutton Maddock, Shropshire | A41 at Woodcote Hill, Shropshire | |
| B4380 | A4169 near Ironbridge, Shropshire | A5 at Montford Bridge, Shropshire | Passes through the south and west of Shrewsbury |
| B4381 | A490/A458 at Welshpool, Powys | B4388 near Welshpool | |
| B4382 | B4389 near Llanfair Caereinion, Powys | B4393 near Lake Vyrnwy, Powys | Crosses A495 |
| B4383 | A488 near Bishop's Castle, Shropshire | A489 near Bishop's Castle, Shropshire | 1 mile long |
| B4384 | A488 at Bishop's Castle, Shropshire | B4385 at Bishop's Castle, Shropshire | Schoolhouse Lane; less than 0.5 miles long |
| B4385 | A4113 at Leintwardine, Shropshire | A458 near Llanfair Caereinion | Passes through Montgomery, Powys; crosses A488, A489 and A483 |
| B4386 | A458/A488 at Shrewsbury | A483 at Abermule, Powys | 26 miles long; crosses A5 and A490 |
| B4387 | A488 at Minsterley, Shropshire | A458 at Halfway House, Shropshire | |
| B4388 | Montgomery, Powys | A458 near Welshpool, Powys | Crosses A490 |
| B4389 | A495 near Llanfair Caereinion, Powys | A483 near Newtown, Powys | Crosses A458 |
| B4390 | A483 at Berriew, Powys | B4389 | |
| B4391 | A490 near Llanfyllin, Powys | A494 at Bala, Gwynedd | Part of former route lies under the nearby reservoir. |
| B4392 | A483 at Arddleen, Powys | A458 at Cyfronydd, Powys | Crosses A490 |
| B4393 | A458 at Ford, Shropshire | Lake Vyrnwy | Crosses A483 and A495; encircles Lake Vyrnwy |
| B4394 | A442 at Wellington, Shropshire | B4380 at Wroxeter | Crosses A5 |
| B4395 | A458 at Llangadfan, Powys | B4393 near Lake Vyrnwy | |
| B4396 | A5 at Nesscliffe, Shropshire | B4393 near Lake Vyrnwy | Crosses A483 and A495 |
| B4397 | B4396 at Knockin, Shropshire | B5063 near Wem, Shropshire | |
| B4398 | B4396 at Knockin, Shropshire | B4393 Llansantffraid, Powys | |
| B4399 | Holme Lacy Bridge | A49 Ross Road | Alternative way to Hereford from the M50 |

## B4400 to B4499

| Road | From | To | Notes |
| B4400 (defunct) | A483 Cross Street and A4083 Leg Street, Oswestry | A483 Beatrice Street, Oswestry | Oswald Road; now part of the B5069 one-way system. |
| B4401 | A5 at Corwen, Denbighshire | A494 near Bala, Gwynedd | |
| B4402 | A494 | B4391 | |
| B4403 | A494 at Llanuwchllyn, Gwynedd | B4391 near Bala, Gwynedd | Runs along the eastern side of Bala Lake |
| B4404 | A489 at Cemmaes Road, Powys | A487 near Machynlleth, Powys | |
| B4405 | A487 at Minffordd, Gwynedd | A493 near Tywyn, Gwynedd | |
| B4406 | B4407 south west of Llyn Conwy, Gwynedd | A5 south east of Betws-y-Coed, Gwynedd | by way of Penmachno |
| B4407 | B4391 near Ffestiniog, Gwynedd | A5 near Pentrefoelas, Gwynedd | by way of Ysbyty Ifan Originally ran from Llan Ffestiniog to Conwy via Betws-y-Coed. By 1932, the southernmost section had become a portion of a rerouted B4408 to Congl-y-Wal and the A496 from there to Blaenau Ffestiniog. By 1939, the B4408 was decommissioned, with the A496 extended over it further to Betws-y-Coed and the section from there to Conwy renumbered to the B5106. Sections became the A4108 and A5110 by 1956, but the ex-B4408 is now the A470 from Llan Ffestiniog to Betws-y-Coed and B5106 north of there; the section just south of the A5 is now unclassified. |
| B4408 (defunct) | | | First used from the B4391 at Pont Tal-y-bont via Tanygrisiau to the B4407 at Rhiwbryfdir. By the end of the 1920s, the southern half was a northern extension of the A496 and the northern section declassified (this section became the B4414 in 1935 when it returned to Class II status). The B4408 was then rerouted south of Blaenau Ffestiniog along the-then B4407 to the A487 near Gellilydan. This B4408 was renumbered to A4108 (now A470) before 1956. |
| B4409 | A5 at Bethesda | A4244 at Glasinfryn | Originally connected linked the B4407 and B4408 south of Blaenau Ffestiniog. Renumbered as a northern extension of the A496 in the mid-1920s and is now unclassified after the A496 was rerouted. |
| B4410 | A498 north of Prenteg | A487 near Maentwrog | Sarn Helen – crosses A4085 at Garreg |
| B4411 | A487 at Glan-Dwyfach, Gwynedd | A497 at Criccieth, Gwynedd | |
| B4412 | A497 at Bryncynan Inn | unclassified road at Morfa Nefyn | Originally began at Pwllheli; this is now part of the A497. |
| B4413 | A499 at Llanbedrog, Gwynedd | Aberdaron, Gwynedd | |
| B4414 (defunct) | B4413 in Llanbedrog | Abersoch | Renumbered as a western extension of the A499 in 1935. |
| B4414 (defunct) | A496 in Rhiwbryfdir | A496 in Pengwarn | Initially a portion of the B4408 but quickly declassified. Received the B4414 number when the route returned to Class II status in 1935. Much of route now part of the A496, except the northmost third which was bypassed and is now unclassified. |
| B4415 | B4413 in Nanhoron | A497 in Efailnewydd | |
| B4416 | A470 near Dolgellau, Gwynedd | A494 near Dolgellau, Gwynedd | Originally ran from Nefyn to the B4412, connecting Nefyn to the rest of the road network. Absorbed into the western extension of the A497 in 1935. |
| B4417 | B4413 in Pen-y-groeslon | A499 in Llanaelhaearn | via Nefyn |
| B4418 | A487 near Pen-y-Groes and Llanllyfni, Gwynedd | A4085 at Rhyd-Ddu, Gwynedd | by way of Nantlle |
| B4419 | A5 in Pentre Berw | A487 in Caernarfon | Exists in two sections; originally connected by a ferry across the Menai Strait, but the ferry was discontinued in 1954. |
| B4420 (defunct) | B5108 (later A5025) in Four Crosses, Menai Bridge | B4422 in Bethel | Originally ended at the B4421 in Newborough, but was quickly extended to Bethel. Much of route became the new A4080 in 1935; the portion into Bethel became the B4422 because the A4080 did not go into Bethel and the northern section became the B5420 (now A5025) because the A4080 did not cross the A5 (the old number would have been out-of-zone north of the A5). |
| B4421 | A4080 in Newborough | B4419 in Llangaffo | |
| B4422 | A4080 south of Bethel | B5109 in Llangefni | Originally began at the B4423 in Llanfaelog, but this was bypassed by the A4080 in 1935 and the route was cut back to Bethel. Originally ended at the A5 near Llangristiolus, but was extended to Llangefni in the 1960s. |
| B4423 (defunct) | B4422 in Llanfaelog | B5112 in Trefor | The section south of the A5 was upgraded to a portion of the A4080 and the northern third became a portion of a rerouted B5112 in 1935. |
| B4423 (defunct) | A465 in Llanvihangel Crucorney | unclassified road in Llanthony | Declassified in the 1970s. |
| B4424 | A40 near Burford | A429 east of Cirencester | Formerly part of the A433 Originally ran along Queen Street in Carmarthen. Likely classified at the last minute (probably early 1923), as the other B442x roads are on Anglesey. Despite surviving the 1935 renumberings, the route is now unclassified and one-way eastbound. |
| B4425 | A40 near Burford | A429 east of Cirencester | Formerly part of the A433 |
| B4426 (defunct) | A431 in Bitton | A430 in Bridgeyate | Became an extension of the B4427 in 1935 and has been upgraded to a portion of the A4175. |
| B4426 (defunct) | A419 Chesteron Lane, Cirencester | A417/A429 in Cirencester | Not shown on maps until the 1940s; the central portion was wiped out by the modern A429 Bristol Road and the remainder is now unclassified. |
| B4427 | B4058 at Hambrook, South Gloucestershire | A38 at Rudgeway | Old Gloucester Road |
| B4428 | B4082 at Binley, Coventry | A5 at Cross in Hand | Previously numbered B4111, A4114, A427, B4027. Numbered B4428 in 2000s. First used from Berkeley to Sharpness. In the 1935 renumbering, it was recommended that the route be extended to the A4135, but this never happened; the B4066 was extended west to Sharpness and the B4428 was declassified instead. Next used from the A429 Fosse Way west of Chesterton to Kemble Airfield (now Cotswold Airport). Became a portion of a rerouted A429 in the 1960s. |
| B4429 | A428 at Rugby | M45/A45 at Thurlaston | |
| B4430 (defunct) | B4456 (now A4148) Wallows Lane, Walsall | A461 (now unclassified) Wednesday Road, Walsall | Declassified; the junction with Wallows Lane at its southern end has closed to vehicular traffic. |
| B4431 (defunct) | B4432 in Coleford | A48 in Wenchford | Much of route now unclassified except for the extension from Coleford to the Robin Hood junction which is part of the B4428. |
| B4432 | A4136 at Five Acres | B4226 at Broadwell | Originally began at Symonds Yat Rock; this section is now unclassified. Originally ran from Marian's Inclosure to Tutshill. By 1932 the first section into Coleford became an extension of the B4431 while the remainder was renumbered to B4228. Later renumberings rerouted the B4228 to take over the section north of Coleford. |
| B4433 | A4067/B4593 in Oystermouth | unclassified road at Mumbles Pier | Originally ran from North Cornelly to Cwrt-y-Defaid. Became a spur of the B4283 in the 1935 renumbering and is now part of the B4283 mainline. |
| B4434 | A474 in Neath | A465 at Resolven | |
| B4435 (defunct) | A474 Herbert Street, Pontardawe | A4067 (now B4603) Brecon Road, Pontardawe | Declassified due to rerouting of the A474. |
| B4436 | A4118 near Langrove | A4067 at Blackpill | |
| B4437 | A44 near Wootton, Oxfordshire | A361 north of Burford | via Charlbury |
| B4438 | A452 in Bickenhill, West Midlands | B4102 at Catherine-de-Barnes, West Midlands | Passes through Birmingham Airport. Section between A45 and just south of Bickenhill replaced by A4545 which opened in December 2024. |
| B4439 | A3400 in Hockley Heath, Warwickshire | A4177 near Hatton | Until full opening of M40, connected A34 to A41. |
| B4440 | A40 at Hotspur | A4094 at Wooburn Green | In the 1935 renumbering, it was proposed that the route be renumbered as an extension of the B476. While this was approved by the MoT, this change never happened. |
| B4441 | A4154 at Sycamore Corner, Amersham | A416 at Oakfield Corner, Amersham | Sycamore Road, Amersham |
| B4442 | A404 at Little Chalfont | A413 at Chalfont St Giles | |
| B4443 | A413 in Aylesbury | A4010 in Stoke Mandeville | Originally continued further to the A418 northeast of Aylesbury town center; this section is now unclassified. |
| B4444 | A4129 in Longwick | A4010 in Princes Risborough | |
| B4445 | A418 at Thame | B4009 at Chinnor | |
| B4446 | A4 in Sonning | B478 in Sonning | |
| B4447 | A4 in Maidenhead | A4094 in Cookham | |
| B4448 | unused | | |
| B4449 | B4044 at Eynsham, Oxfordshire | A4095 at Bampton | |
| B4450 | Chipping Norton, Oxfordshire | A436 east of Stow-on-the-Wold | via Bledington |
| B4451 | B4100 at Gaydon, Warwickshire | A425 at Southam, Warwickshire | |
| B4452 | A425 at Ufton Cross Roads (east of Ufton) | B4451 at Deppers Bridge | |
| B4453 | A445 in Leamington Spa, Warwickshire | A45 at Dunstore Heath near Rugby, Warwickshire | |
| B4454 (defunct) | B4106 Spon End, Coventry | B4107 (later A4114) Queen Victoria Street, Coventry | In the 1960s, the eastern half was wiped out by the A4053; the western half is now the B4101. The route was occasionally labeled as B4464 (a typo), but the origin of this error is uncertain. Number also appears in Wednesfield on online maps before 2009, but this is a typo for the B4484. March End Road is now part of the U99 and Alfred Square Road is possibly unclassified. |
| B4455 | A429 near Halford, Warwickshire | A5 at High Cross, Leicestershire | Part of the Fosse Way (Roman road) Originally ran from Wolvey Heath to Cross in Hand. Declassified in the mid-1970s due to completion of the M69. The ex-B4455 crosses the current B4455 at Cloudesley Bush. |
| B4456 (defunct) | A461 in Pleck, Walsall | A461 northeast of Walsall town center | Walsall Ring Road; loop completed by the mid-1940s. The southwest corner was always part of the A461 mainline while the northwest corner never existed as part of the B4456. Now upgraded to the A4148. |
| B4456 (defunct) | | | Provisional number for the former A49 through Ludlow after it was rerouted onto the eastern bypass. Number never used; the B4361 was extended over the route instead. |
| B4457 | A4110 at Stretford Bridge | A44/A4412 at Golden Cross | Originally continued to the original A44 at Upper Hardwick as the A44 did not exist at this location; this is now part of the A44. |
| B4458 | A48 (now B4293) Monnow Street, Monmouth | A446 in Monmouth | Declassified. |
| B4458 | | | Typo for the B4588. |
| B4459 | A485 south of Pencader | B4338 in Talgarreg | Original route to Rhos Ymryson declassified since the 1970s. Originally ran from Bow Street to Capel Dewi. Upgraded to Class I status in 1935, becoming the A4159. |
| B4460 (defunct) | Craven Park Road, Harlesden | High Street, Harlesden | Manor Park Road, Harlesden; now the northwest–southeast carriageway of the A404 gyratory. |
| B4461 | M48 at Aust | B4061 at Alveston | |
| B4462 (defunct) | A429 in Barford | A41 at The Asps (south of Warwick) | Declassified in 1991 after the Waterstock-Longbridge section of the M40 opened. |
| B4463 | A46 at Sherbourne | A4189 west of Hampton on the Hill | |
| B4464 | A454, near Willenhall, West Midlands | A454/M6 junction, Bentley, West Midlands | Former route of A454 through Willenhall Town Centre. Extended through Bentley to M6 J10 when A454 rerouted along Black Country Route. Originally ran along Sutton Road in Kidderminster. Now part of the A4535. |
| B4465 | A420 at Easton, Bristol | A46 near Tormarton | Passes through Chester Park, Staple Hill and Pucklechurch, ending near Junction 18 of the M4. Prior to c1962, continued east from Pucklechurch, through Hinton, to A46 at Burton. |
| B4466 | A4 (Hotwells Road), Bristol | A4018 at Clifton, Bristol | Jacob's Wells Road |
| B4467 | B3129 in Clifton, Bristol | A4176 at Clifton Down | Pembroke Road |
| B4468 | A4018 at Durdham Down, Bristol | A38 at Horfield, Bristol | Coldharbour Road and Kellaway Avenue |
| B4469 | A38 at Horfield, Bristol | A420 at St George, Bristol | Muller Road and Rose Green Road |
| B4470 (defunct) | A487 at Trawsfynydd | B4493 at Bryn Maenllifo | Reserved in 1964; renumbered to A4212 in 1968. |
| B4471 | A472 at Hafodyrynys | A4046 at Aberbeeg | |
| B4472 (defunct) | A472 at Cwm-dows, Newbridge | A472 in Crumlin | Declassified. |
| B4473 | A458 west of Shrewsbury | B4380 at Montford Bridge, Shropshire | 1 mile long; crosses A5 |
| B4474 (defunct) | James Steeet, Portardawe | High Street, Portardawe | Later rerouted along Dynevor Terrace (this became a stub of the A474). Both routes now unclassified. |
| B4475 (defunct) | A483 Garth Road, Builth Wells | Wye Bridge, Builth Wells | Now part of the A483 one-way system. |
| B4476 | B4624 in Llandysul | A475 at Pren-gwyn | |
| B4477 | A361 at Broughton Poggs | B4047 at Minster Lovell | Originally ran from New Tredegar to Rhymney. Declassified by 1961 due to numerous landslides. |
| B4478 | A4046/A4281 in Willowtown | A4046 in Briery Hill | |
| B4479 | A44 in Bourton on the Hill | B4035 in Charingworth | |
| B4480 (defunct) | A34 (now A3400) north of Wootton Wawen | A435 at Ullenhall | Declassified around 1990. |
| B4481 (defunct) | A423 in Willenhall | A46 near Walsgrave | Section north of Binley is now part of the B4082 while the remainder is unclassified. |
| B4482 | B4550 in Brickfields, Worcester | A38 in Perdiswell | Former portion of the A4536. |
| B4483 | B4163 in Coseley, West Midlands | A457 in Woodsetton, West Midlands | Not signposted off A457. |
| B4484 | A460 in Fallings Park, Wolverhampton | Bilston Town Centre | Rerouted in Willenhall when town centre pedestrianised. Extended into Bilston along former A463 route when Black Country Route opened. |
| B4485 | A44 at Worcester | A4440 at Worcester | Originally ran along Wylds Lane in Worcester; the eastern half may have been part of an extended B4205 before the entire route received the B4485 number. One old map shows the route as B4085, despite that number existing on a route near Eversham since 1922. Whatever the result, the route was short-lived; the western half is now unclassified and the eastern half part of the B4205. |
| B4486 | A4281 in Pont-y-gof | A4046 in Waun Lwyd | |
| B4487 | A4161 in Roath | A48 in St Mellons | Exists in two sections, separated by a 1.3 km (0.81 mi) gap. |
| B4488 | A48 at Waun-gron Park | B4267/A4119 at Llandaff Fields | |
| B4489 | A483 at Swansea | A48 and the M4 at J46 | |
| B4490 (defunct) | A4048 Gladstone Street, Crosskeys | A467 (now B4591) St Mary Street, Risca | Declassified. |
| B4491 | North Circular Road at Gunnersbury | B452 at Northfields, near Northfields Underground station | Passes Gunnersbury Park. Road Names: Popes Lane, Little Ealing Lane. |
| B4492 | A4000 at Gypsy Corner, North Acton just north of the A40, Western Avenue | A4000 at Harlesden, just south of the A404 | "Alternative" route through Park Royal via North Middlesex Hospital. Road Names: Park Royal Road, Acton Lane. |
| B4493 | A34 at Chilton, Oxfordshire | A4130 at Didcot, Oxfordshire | Road originally ran through Harwell, Oxfordshire and terminated on the A417 but was extended to Chilton in 2016 to meet a new junction with the A34 and A4185. |
| B4494 | A4 at Newbury | Wantage | |
| B4495 | A4144 Abingdon Road, Oxford | A4165 Banbury Road, Summertown, Oxford | Passes through the east of Oxford, over Donnington Bridge, through Cowley and Headington, then Marston Ferry Road |
| B4496 (defunct) | A420 Park End Street, Oxford | A4144 St Giles, Oxford | Now part of the A4144 (old A4144 is now pedestrianized). |
| B4497 | B4101 in Beoley | A435 in Washford | |
| B4498 (defunct) | A41 (now B4100) Old Snow Hill, Birmingham | A34/B4144 in Lozells | Declassified in the 2010s. |
| B4499 | A488 at Minsterley, Shropshire | B4386 at Brockton, Shropshire | |

## B4500 to B4599

| Road | From | To | Notes |
| B4500 | B5070 at Chirk, Wrexham | B4580 at Llanrhaeadr, Powys | Also allocated to the bypassed section of the A4071 in Rugby. Signs were erected showing the B4500, but when Warwickshire County Council realized that the number was a duplicate, a new sign was erected showing the B4642 number. Soon after this, all signs were patched over to show B4642. |
| B4501 | A543 at Denbigh, Denbighshire | A4214 at Fron-Goch, Gwynedd | passes Llyn Brenig, Alwen Reservoir and crosses A5 at Cerrigydrudion |
| B4502 | unused | | |
| B4503 | A449 at North Malvern | A4103 in Leigh Sinton | |
| B4504 | A441/A448 in Crabbs Cross | A448 at Pitcher Oak Wood | Originally ran from Rickmansworth to Watford. Upgraded to Class I status in the 1970s, becoming the A4145. |
| B4505 | A4251 at Hemel Hempstead | A416 at Newtown, Chesham | |
| B4506 | A4251 in Northchurch | B489 at Whipsnade | |
| B4507 | Wantage | B4000 at Ashbury | Formerly continued east via Bishopstone and Wanborough to meet the A419 east of Swindon; this section is now unclassified. |
| B4508 | A420 west of Kingston Bagpuize | B4000 east of Sevenhampton | |
| B4509 | B4060 at Wickwar | A38 at Falfield | |
| B4510 | B4035 at Bengeworth | B4085 at North Littleton | |
| B4511 | A4049 at Aberbargoed | A4048 at Bedwellty | |
| B4512 | A4058 at Ystrad | A4233 near Tylorstown | |
| B4513 (defunct) | A4100 Randal Hill Road, Old Hill | A459 Halesowen Road, Old Hill | Declassified when the A459 was realigned to bypass Old Hill. |
| B4514 | B4217 in Acock's Green, Birmingham | A41 in Olton, Birmingham | |
| B4515 | A41/B4100 at Gib Heath | A34 and B4144 at Lozells | |
| B4516 | B4145 in Saltley, Birmingham | B4114 in Washwood Heath, Birmingham | |
| B4517 | A4037 in Tipton, West Midlands | A461 in Great Bridge, West Midlands | Road diverted through new tunnel under railway in Tipton replacing level crossing on West Coast Main Line. |
| B4518 | A470 at Rhayader, Powys | Llanbrynmair | |
| B4519 | A483 at Garth, Powys | B4520 north of Upper Chapel, Powys | runs beside MoD's artillery range on Mynydd Epynt |
| B4520 | A483 at Builth Wells, Powys | B4601 at Brecon, Powys | |
| B4521 | A49 five miles west of Ross-on-Wye, Herefordshire | A40 at Abergavenny, Monmouthshire | Road is approximately 20 miles long, heading in a south westerly direction from Herefordshire into South Wales. Near its western end it forms a part of the border of the Brecon Beacons National Park. |
| B4522 | A4061 at Treherbert, Rhondda Cynon Taf | Blaencwm, Rhondda Cynon Taf | Road lasts approximately 3⁄4 of a mile. Although on OS maps it is not displayed as the B4522, it is signposted as the B4522 on the A4061 in the local vicinity. Maps show it as Dunraven/Gwendoline Street, Treherbert. |
| B4523 (defunct) | A4119 Dunraven Street, Tonypandy | A4058 Miskin Road, Tonypandy | Bridge over the Rhondda gone due to the present A4058; the eastern end is now the B4278 and the remainder unclassified. |
| B4524 | A48 near Corntown, Vale of Glamorgan | B4265 at Ewenny, Vale of Glamorgan | |
| B4525 | A422 at Middleton Cheney, Banbury | A43 near Syresham, Brackley | Road begins 1 mile east of the M40 J11 and is classified as a country route which connects to the A43, whilst bypassing Brackley. This road has been greatly truncated at its eastern end. Formerly, it ran to Northampton by way of Thorpe Mandeville, Moreton Pinkney, Adstone, Litchborough and Bugbrooke this route has been declassified. |
| B4526 | Goring, Oxfordshire | A4074 near Woodcote, Oxfordshire | |
| B4527 (defunct) | B4006 Victoria Road, Swindon | A361 (now B4289) Drove Road, Swindon | Declassified in the 2000s. The number was still included in the 2005 DfT road lists, but it had been declassified by then. |
| B4528 | A420 in Chippenham | B4158 Malmesbury Road in Chippenham | Road is 1⁄2 a mile long. Originally ran from Brimfieldcross into Brimfield itself. Upgraded to Class I status, becoming the A4105 in 1971, but has been declassified again due to completion of the A49 Brimfield bypass. |
| B4529 | A4110 near Leominster, Herefordshire | B4360 near Leominster | Originally ran from Shirl Heath to Lawton Cross. Declassified in the 1980s when the road it met at its southern end (the A44) was also declassified. |
| B4530 | A4113 at Walford, Herefordshire | A4110 at Adforton, Herefordshire | |
| B4531 | A4040 in Erdington, Birmingham | A5127 in Erdington | |
| B4532 | A456 in Edgbaston, Birmingham | B4217 in Edgbaston | |
| B4533 (defunct) | B4130 Cheapside, Birmingham | A435 in Stratford Place, Birmingham | Declassified after the 1980s. |
| B4534 | A3102 in Freshbrook, Swindon | A4311 in Blunsdon | Begins near M4 J16 and banks in a north-westerly direction. A change in the road system in Blunsdon meant closure of part of the original route at Lady Lane, which is no longer accessible to motor vehicles. The B4534 regains its status at the northern end of Lady Lane where it continues to its terminus at the A4311. Originally ran in Stratford-upon-Avon from Evesham Place to the A34 Birmingham Road. Upgraded to Class I status in the 1970s as the A4134, but within 10 years this was renumbered to a portion of the A4390. |
| B4535 (defunct) | A422/A439 in Stratford-upon-Avon | A34 in Stratford-upon-Avon | Ran past Shakespeare's birthplace; now pedestrianized. |
| B4536 | B4084 in Pershore | A4104 on the outskirts of Pershore | |
| B4537 | A461 in Wollaston, West Midlands | A458 near Wollaston | |
| B4538 (defunct) | A45 Western Avenue, Daventry | B4036 in The Market Place, Daventry | Originally portions of the A425 and B4036, but gained its own number after the A45 Western Avenue was built. Declassified after the A45 was rerouted again. |
| B4539 (defunct) | A41 North Western Avenue, Watford | A412 St Albans Road, Watford | Declassified. |
| B4540 | B4506 near Edlesborough | A5 near Dunstable | |
| B4541 | B489 in Dunstable | B4540 near Whipsnade | |
| B4542 | A4125 in Eastbury | A4125 near Oxhey and A4008 in South Oxhey | |
| B4543 (defunct) | | | Reserved in 2003 for the "Dawley Donnington Distributor Road" in Telford. This is probably referring to what is now the B4373, although it is unknown if the B4543 number was ever used on the ground. |
| B4544 | A429 in Coventry | A4600 in Coventry | Former portion of the A46. Originally ran from Stoke Mandeville to Aston Clinton. Downgraded to the C142 in 2003 when Aston Clinton was bypassed. |
| B4545 | A5 at Valley | A5154 at Holyhead | |
| B4546 | A487/A478 road roundabout near Cardigan | Poppit Sands | goes through St Dogmaels |
| B4547 | A4086 at Cwm-y-glo | A4244 / B4366 | |
| B4548 | A487 near Cardigan | Gwbert | |
| B4549 | A456 Bewdley Hill at Kidderminster, Worcestershire | A451 Stourport Road at Kidderminster | Sutton Park Road; 1 mile long |
| B4550 | Near A38 in Worcester | Near A4536 in Worcester | Road links Worcester City Centre to the north of Worcester. |
| B4551 | A456/A459 in Halesowen, West Midlands | A491 near Lydiate Ash, Worcestershire | |
| B4552 (defunct) | A452 at Castle Bromwich Bridge, Castle Bromwich | A47 Bradford Road, Castle Bromwich | The northern end was split off when M6 J5 was built, and part of the road is now gone, lost under the roundabout. The remainder along Chester Road is now unclassified and Hall Road is now part of a rerouted B4118. |
| B4553 | B4040 in Cricklade | A3102 in Toothill | Originally ran from Tenbury Wells to Leominster. Upgraded to Class I status in the 1960s, becoming an eastern extension of the A4112. |
| B4554 (defunct) | A483 Wind Street, Ammanford | A483 College Street, Ammanford | Loop off the A483; declassified by the mid-1980s. |
| B4555 | Bridgnorth, Shropshire | B4363 near Highley, Shropshire | |
| B4556 | A476 in Gorslas | A483 at Llandybie | |
| B4557 | A406, Neasden | B4565 at Wembley Stadium | Link road between Wembley Stadium and industrial estates with IKEA store and Tesco in Brent Park Originally ran from Brecon to Bishop's Meadow. Upgraded to Class I status around 1960, becoming the A4062. But when the A40 Brecon bypass opened in 1980, it returned to Class II as the B4602 except for the southernmost section, which was declassified. |
| B4558 | A40 east of Brecon | A4077 southwest of Crickhowell | Parallels A40 in the Usk valley; passes through Pencelli, Talybont-on-Usk, Cwm Crawnon and Llangynidr. Likely classified in the mid-1930s, as it does not appear on a 1934 map, but it does appear on a 1939 map. Also appears on the former A459 north of Dudley. This is a typo for the B4588. |
| B4559 | A4067 in Defynnog | A470 southwest of Brecon | Reclassified to the A4215 around 1970. |
| B4560 | A40 near Bwlch | A4047 at Beaufort, Blaenau Gwent | |
| B4561 (defunct) | A44 in Worcester | A38 in Worcester | Declassified. |
| B4562 | A469 in Llanishen | B4487 at St Mellons | |
| B4563 | A459, High Holburn, Sedgley | A463, Gospel End Street, Sedgley. | Vicar Street, Sedgley. Passes All Saints Parish Church. Not signed. |
| B4564 | A4093 at Hendreforgan | B4564 at Gilfach Goch | |
| B4565 (defunct) | A4089 Wembley Park Drive, Wembley | A404 Harrow Road, Wembley | Upgraded to the A479 in 2007 when the new Wembley Stadium opened. |
| B4566 (defunct) | B461 in Stanmore Marsh | B454 in Neasden | Now the southern end of the A4140. |
| B4567 | A481 north of Llanfaredd | B4594 at Erwood Bridge | |
| B4568 | A470 near Caersws, Powys | B4389 near Newtown, Powys |
| B4569 | B4518 at Llanidloes, Powys | B4568 at Caersws, Powys | |
| B4570 | A484 near Cardigan | B4333 at Cwm-cou | |
| B4571 | B4333 at Newcastle Emlyn | A486 in Ffostrasol | |
| B4572 | A487 in Aberystwyth | B4353 in Borth | |
| B4573 | A496 at Harlech, Gwynedd | A496 | |
| B4574 | A4120 at Devil's Bridge, Aberystwyth | B4518 near Rhayader, Powys | Described by the AA as one of the ten most scenic drives in the world. |
| B4575 | A485 in Llanilar | B4340 in Trawsgoed | |
| B4576 | A485 at Abermad, Ceredigion | B4342 at Nantcwnlle, Ceredigion | |
| B4577 | B4578 at Tyncelyn | A487 at Aberarth | |
| B4588 | A485 at Tyncelyn | A485 at Llanio | |
| B4579 | A5/A483 at Oswestry, Shropshire | B4500 at Glyn Ceiriog, Wrexham | |
| B4580 | A5/A495 at Oswestry, Shropshire | B4391 near Llanfyllin, Powys | |
| B4581 (defunct) | A487/A4120/B4340 in Penparcau | A44 in Llanbadarn Fawr | Due to its importance, it became an extension of the A4120 in the late 1960s. |
| B4582 | A487 at Llantood, north Pembrokeshire | A487 near Newport, Pembrokeshire | Via Glanrhyd and Nevern |
| B4583 | A487 at St Davids | car park at Whitesands Bay | |
| B4584 | A4139 at Lamphey | unclassified road at Freshwater East | Originally continued north back to the A4139 east of Lamphey, but this was declassified in the 1970s as it was too narrow. |
| B4585 | A4139 at Bier Cross | A4139 at Skrinkle | |
| B4586 | A477 in Broadmoor | A4075 at Yerbeston | |
| B4587 | B4176 in Dudley Town Centre | B4177 in Dudley | |
| B4587 | B4006 in Rodbourne Cheney | B4534 in Haydon Wick | Duplicate number. |
| B4588 | A459 in Upper Gornal, Dudley | B4176 in Dudley town centre | Roads named Burton Road, Highland Road and Salop Street |
| B4589 (defunct) | | | Described in the c. 2002 DfT Road List as being located in Telford. The route does not appear on any maps, so it is likely defunct and may have even been a typo on that list. |
| B4590 | B4484 near Willenhall, West Midlands | A462 near Willenhall | Previously part of A463 (later A454) when the first section of The Keyway opened. Not signed as B4590; eastbound is signed as part of the A462 and westbound is signed as part of the B4484. |
| B4591 | B4237 at Newport | A467 at Abercarn | The former A467 route into central Newport. |
| B4592 | unused | | |
| B4593 | A4067 at Mumbles | Caswell Bay | |
| B4594 | A44 near Walton, Powys | B4567 near Erwood | |
| B4595 | A4058 near Pontypridd | A4119 at Talbot Green | Road originally started at Llantwit Fardre but following the completion of the Church Village bypass, most of the former A473 route became part of the B4595. The A4058 near Glyntaff also became part of the B4595. This road also has three road links, one near the A470 in Glyntaff where the A4058 originally started, the other in Tonteg near Powerstation hill and another near Beddau where the A473 originally ran. |
| B4596 | B4591 at Newport | B4236 at Caerleon Bridge | The former A449 route into central Newport. |
| B4597 | unused | | |
| B4598 | A4042/A465/A40 at Abergavenny | A472 at Usk | Former A471 and A40. |
| B4599 | A4067 in Ystalyfera | A4067 near Penrhos | |

## B4600 to B4801

| Road | From | To | Notes |
| B4600 | Penrhos roundabout (A468/A469) | Crossways roundabout (A468) | Former routing of the A468 through Caerphilly. |
| B4601 | A470/A40 roundabout east of Brecon, Powys | A470/A40 roundabout southwest of Llanfaes near Brecon, Powys | former route of A40 prior to construction of Brecon Bypass |
| B4602 | A470 junction northeast of Brecon, Powys | B4601 Heol Gouesnou, Brecon, | former route of A470 prior to construction of Brecon Bypass |
| B4603 | A483/A4118 junction at Greenhill, Swansea | A4067 near Cilmaengwyn | |
| B4604 - B4619 | unused | | |
| B4620 | A483 at Fforestfach | A4240 at Loughor |
| B4621 | unused | | |
| B4622 | A473 at Brynitirion, Bridgend | A48 Bridgend bypass | |
| B4623 (defunct) | | | Number apparently appears on a slightly blurred late 1950s map along Wales Farm Road in North Acton, but the true number is not known. Now part of the A4000 one-way system. |
| B4623 (defunct) | | | Assigned to the former A469 through Caerphilly; although the number seems to be a typo for the B4263, it did appear on maps as well as on official documentation in the 2000s. Possibly due to confusion, the section south of the B4600 is now part of the B4263 and the northern section is now unclassified. |
| B4624 | A44 at Evesham | A4184 at Evesham | Worcester Road. |
| B4625 | A4067 at Tircanol | Lon-las Interchange (M4 J44) | Unsigned |
| B4626 - B4629 | unused | | |
| B4630 | Noke roundabout (A405), Chiswell Green | A5183 in St. Albans | Former portion of the A412. |
| B4631 | unused | | |
| B4632 | Stratford-upon-Avon | Cheltenham | Old A46. Passes through Winchcombe, Prestbury, near Stanton, Broadway, Aston-sub-Edge, Wootton-sub-Edge, Mickleton, Clifford Chambers |
| B4633 | A40 in Cheltenham | A419 in Cheltenham | Was the B4076 in 1922 and later an extension of the B4075. Route not signed. |
| B4634 | B4063 at Staverton Bridge | A4019 at Uckington | Was the B4063 before it was extended over the former A40. |
| B4635 | A4251, Tring | A41, Drayton Beauchamp | Old A4251. Passes through the town of Tring meeting the B488 on the first and last junction with the B4009. Covers the old A4251/A41 route. |
| B4636 | B4205 at Worcester | A4538 at Tibberton | Existed in 1922, but not classified until the 2000s. |
| B4637 | B4205 in Worcester | B4638 at Woodgreen | |
| B4638 | B4636 at Lyppard Grange | B4639 at Warndon | |
| B4639 | B4550 at Blackpole | A4440 at Warndon | |
| B4640 | Newbury | Tot Hill | Former portion of the A34 road; out-of-zone as it runs south of the A4. Until it was replaced by the Newbury Bypass it was originally the only part of the road between Oxford and Winchester that was not a dual carriageway. Unknown why the B4640 number was chosen as it has no relation to the A34. |
| B4641 | Brockworth Interchange (M5 J11A) | Gloucester Business Park | |
| B4642 | A4071 south west of Rugby, Warwickshire | A426 in central Rugby | Old route of the A4071 before the building of the Rugby Western Relief Road. |
| B4643 | B4528 at Patterdown Farm | A4 at Rowden Hill | Formerly the A350 before it was rerouted onto what is now the B4528. Some maps label the route as the B4634 (a typo). |
| B4644 - B4649 | unused | | |
| B4650 (reserved) | | | Reserved in 2006 for a downgrade of the A417 between Cirencester and Faringdon. The road has not yet been numbered and there are currently no plans to do so. |
| B4651 - B4665 | unused | | |
| B4666 | Dodwells Roundabout (A5/A47) in Hinckley | B590 (Hinckley inner ring road) at Hinckley | Out-of-zone as it runs east of the A5; former portion of the A47. |
| B4667 | B590 in Hinckley | A47 Hinckley northern bypass | Given a Zone 4 number, despite it existing north of the A5; former portion of the A447. |
| B4668 | B590 in Hinckley | A47 Hinckley northern bypass | Out-of-zone as it runs east of the A5; former portion of the A47. |
| B4669 | B590 at Hinckley | B4114 at Sapcote | Was the B579 from 1922 to 1926, the A5070 from 1926 to the late 1970s and the B4069 from then until 1990. Given a Zone 4 number, despite existing north of the A5. |
| B4670 - B4695 | unused | | |
| B4696 | A419 north of Latton | B4042 west of Royal Wootton Bassett | Runs west through gravel workings and the Cotswold Water Park as Spine Road (begun 1971), then turns south on older road through Ashton Keynes towards Wootton Bassett. |
| B4697 - B4729 | unused | | |
| B4730 (defunct) | | | Typo for the B4130. |
| B4731 - B4739 | unused | | |
| B4800 | | | Section of former A483 in Newtown, designated in 2019 after the town's bypass opened. |
| B4801 | | | Section of former A489 in Newtown, designated in 2019 after the town's bypass opened. |