- A48 between A484 and B4310, Carmarthenshire (Grid ref SN467180)
- A48 between B4310 and A476, Carmarthenshire (Grid ref SN501170)
- A48 between A476 and M4 j49, Carmarthenshire (Grid ref SN571095)
- A48 between M4 j49 and A4138, Carmarthenshire (Grid ref SN586041)
- A48 between A4138 and A48 merge, Swansea (Grid ref SN591037)
- A48 between A4138 and A48 merge, Swansea (Grid ref SN591038)
- A48 between A48 merge and A4240, Swansea (Grid ref SN611000)
- A48 between A4240 and M4jn47, Swansea (Grid ref SS618991)
- A48 between M4 jn47 and M4 jn46, Swansea (Grid ref SS640989)
- A48 between M4 jn46 and A4067, Swansea (Grid ref SS657988)
- A48 between A4067 and A4217, Swansea (Grid ref SS680976)
- A48 between A4217 and M4 jn44, Swansea (Grid ref SS700976)
- A48 between M4 western spur and A474, Neath Port Talbot (Grid ref SS739939)
- A48 between A474 and B4286, Neath Port Talbot (Grid ref SS743930)
- A48 between B4286 and M4 J41, Neath Port Talbot (Grid ref SS750922)
- A48, Aberavon, Neath Port Talbot (Grid ref SS762901)
- A48 between M4 jn41 and A4107, Neath Port Talbot (Grid ref SS763899)
- A48, Margam Moors, Neath Port Talbot (Grid ref SS769891)
- A48 between A4107 and M4 J39, Neath Port Talbot (Grid ref SS781880)
- A48 between A4241 and M4 Junction 39, Neath Port Talbot (Grid ref SS791868)
- A48 between M4 jn39 and M4 jn38, Neath Port Talbot (Grid ref SS792867)
- A48 between A4241 and M4 Junction 38, Neath Port Talbot (Grid ref SS793864)
- A48 between M4 jn38 and Neath Port Talbot boundary, Neath Port Talbot (Grid ref SS811850)
- A48 between Bridgend boundary and A4229, Bridgend (Grid ref SS826822)
- A48 between A4229 and A4106, Bridgend (Grid ref SS857800)
- A48 between A4106 and A473 Laleston, Bridgend (Grid ref SS867798)
- A48 between A473 Laleston and B4622, Bridgend (Grid ref SS880791)
- A48 between B4622 and Bridgend boundary, Bridgend (Grid ref SS900785)
- A48 between Bridgend boundary and A473, Bridgend (Grid ref SS914785)
- A48 between A473 Heronston and LA boundary, Bridgend (Grid ref SS919783)
- A48 between LA boundary and A4222 Gibbet's Hill, The Vale of Glamorgan (Grid ref SS950764)
- A48 between A4222 Gibbet's Hill and A4222 Primrose Hill, The Vale of Glamorgan (Grid ref ST000747)
- A48 between A4222 Primrose Hill and A4226, The Vale of Glamorgan (Grid ref ST050742)
- A48 between A4226 and A4232 / A4050, The Vale of Glamorgan (Grid ref ST100745)
- A48 between A4232 / A4050 and A4161, Cardiff (Grid ref ST120750)
- A48 between A4161 and A4119, Cardiff (Grid ref ST150774)
- A48 between A4119 and A469 / A470, Cardiff (Grid ref ST160781)
- A48 between A469 / A470 and A4161, Cardiff (Grid ref ST200787)
- A48 between A4161 and A4232, Cardiff (Grid ref ST207800)
- A48 between A4232 and A48M jn29a, Cardiff (Grid ref ST220818)
- A48 between J29 and Cardiff boundary, Cardiff (Grid ref ST237822)
- A48 between A48M and Cardiff boundary, Cardiff (Grid ref ST240821)
- A48 between Newport boundary and Celtic Way, Newport (Grid ref ST250832)
- A48 between Newport boundary and J29A, Newport (Grid ref ST250836)
- A48 between Celtic Way and M4jn28 / A467, Newport (Grid ref ST283850)
- A48 between M4jn28 / A467 and A4042 Maes Glas, Newport (Grid ref ST290859)
- A48 between A4042 Maes Glas and A4042 Queen St, Newport (Grid ref ST300865)
- A48 between A4042 Queen St and A455, Newport (Grid ref ST320878)
- A48 between A4042 and A455, Newport (Grid ref ST336866)
- A48 between A4042 and A4810, Newport (Grid ref ST336866)
- A48 between A4810 and A455, Newport (Grid ref ST345870)
- A48 between A455 and Llanwern Rd, Newport (Grid ref ST350889)
- A48 between Llanwern Rd and M4 J24, Newport (Grid ref ST355893)
- A48 between A455 and M4 Junction 24, Newport (Grid ref ST360893)
- A48 between M4 jn24 and Newport boundary, Newport (Grid ref ST400911)
- A48 between M4 jn24 and Newport boundary, Newport (Grid ref ST400911)
- A48 between Monmouthshire boundary and A466, Monmouthshire (Grid ref ST498903)
- A48 between A466 and England, Monmouthshire (Grid ref ST530934)
- A48 between Gloucestershire boundary and Roundabout just north of Mead Lane, by Lydney, Gloucestershire (Grid ref SO597000)
- A48 between roundabout just north of Mead Lane, by Lydney and Highfield Rd, Gloucestershire (Grid ref SO646025)
- A48 between Highfield Road and A4151, Gloucestershire (Grid ref SO680089)
- A48 between A4151 and A40, Gloucestershire (Grid ref SO754154)