The A40 is a trunk road which runs between London and Goodwick (Fishguard), Wales, and officially called The London to Fishguard Trunk Road (A40) in all legal documents and Acts. Much of its length within England has been superseded by motorways, such as the M40, and has lost its trunk road status, though it retains it west of Gloucester, including its length within Wales. It is approximately 260 miles (420 km) long. The eastern section from Denham, Buckinghamshire to Wheatley, Oxfordshire is better served by the M40 and its former function of linking London with Cheltenham and Gloucester has been taken by the M4, A419 and A417 via Swindon.
The A470 is a trunk road in Wales. It is the country's longest road at 186 miles (299 km) and links the capital Cardiff on the south coast to Llandudno on the north coast. While previously one had to navigate the narrow roads of Llanidloes and Dolgellau, both these market towns are now bypassed due to extensive road modernisation. The 26 miles (42 km) from Cardiff Bay to Merthyr Tydfil are mainly dual carriageway, but most of the route from north of Merthyr to Llandudno is single carriageway.
The A483, officially described as the Swansea to Manchester Trunk Road, although now ending in Chester, is a major road in the United Kingdom. It runs from Swansea in Wales to Chester in England via Llandovery, Llandrindod Wells, Oswestry and Wrexham, a distance of around 153 miles (246 km).
The A55, also known as the North Wales Expressway, is a major road in Wales and England, connecting Cheshire and North Wales. The vast majority of its length from Chester to Holyhead is a dual carriageway primary route, with the exception of the Britannia Bridge over the Menai Strait and several short sections where there are gaps in between the two carriageways. All junctions are grade separated apart from a roundabout east of Penmaenmawr and another nearby in Llanfairfechan. Initially, the road ran from Chester to Bangor. In 2001, it was extended across Anglesey to the ferry port of Holyhead parallel to the A5. The road improvements have been part funded with European money, under the Trans-European Networks programme, as the route is designated part of Euroroute E22.
The A48(M) motorway in Wales links Cardiff with Newport. It is a 2-mile (3.2 km) long M4 spur. At St Mellons, it runs continuously into the dual-carriageway A48, which also has (albeit narrow) hard shoulders. The A48(M) has no other junctions and opened in 1977. The M4 was extended from junction 29 in 1980.
The A449 is a major road in the United Kingdom. It runs north from junction 24 of the A48 road at Newport in South Wales to Stafford in Staffordshire.
The A4042 is a trunk road that runs from Abergavenny to Newport in south Wales.
The A477 is a major road in South Pembrokeshire and Carmarthenshire connecting St Clears and Johnston. Its route includes the Cleddau Bridge, a former toll bridge linking Pembroke Dock and Neyland.
The A4060, also known as the East of Abercynon to East of Dowlais Trunk Road, is a trunk road in Wales.
The A4076 is a 9 miles (14 km) long, primary trunk road in Pembrokeshire, Wales. The A4076 begins at the Salutation Square roundabout junction with the A40 by Pembrokeshire County Hall, then bypasses Haverfordwest to the southeast and continues south to the oil refineries, now converted into petroleum storage and distribution terminals, at Milford Haven.
The A479, officially also known as the Glanusk Park (Crickhowell)—Llyswen Trunk Road, is a trunk road in Wales. It connects Crickhowell to Llyswen via the Rhiangoll valley and Talgarth, running through the Brecon Beacons National Park.
Trunk roads in Wales were created in the Trunk Roads Act of 1936 when the UK Ministry of Transport took direct control over 30 of the principal roads in Great Britain from English, Welsh and Scottish local authorities. The number of trunk roads was increased from 30 to 101 in the Trunk Roads Act of 1946. These roads formed what the Act called "the national system of routes for through traffic". Since Welsh devolution the trunk road system in Wales has been managed by the South Wales Trunk Road Agent and the North and Mid Wales Trunk Road Agent on behalf of the Welsh Government. As of April 2019, out of a total of 34,850 miles (56,090 km) of roads in Wales, 1,576 miles (2,536 km) are trunk roads.
