Route description

The A4240 begins at the roundabout at the Loughor

Loughor

Loughor is a town in the City and County of Swansea, Wales, within the historic county boundaries of Glamorgan, Wales. It lies on the estuary of the River Loughor. The town has a community council called Llwchwr....

 side of the Loughor bridge

Loughor bridge

The Loughor bridge is a road bridge crossing over the River Loughor, providing a convenient link between much of western Swansea and Llanelli, west Wales. The bridge is part of the A484 road. The road bridge is adjacent to the Loughor railway viaduct. A permanent bridge linking Loughor and...

. The road heads east through Loughor, then onwards through Gorseinon

Gorseinon

Gorseinon is a town in southwest Wales, near the Loughor estuary. It was a small village until the late 19th century when it grew around the coal mining and tinplate industries. It is situated in the north west of Swansea, around north west of the city centre...

, where it forms the east-west main road intersecting with the B4296 in central Gorseinon. The A4240 then continues through the Garngoch Industrial Estate and then through Penllergaer

Penllergaer

Penllergaer is a village in the City and County of Swansea, Wales, UK, falling within the Penllergaer ward. Penllergaer is situated about 6 miles north west of Swansea city centre, near the M4 Motorway at Junction 47.-Features:...

 after which it continues along a single carriageway shared with the A48

A48 road

The A48 is a major trunk road in Great Britain. It runs from the A40 at Highnam west of Gloucester to the A40 at Carmarthen. Before the construction of the M4 motorway and the first Severn Bridge in the mid 1960s it was the principal route into South Wales. For most of its journey through Wales,...

 until it reaches the roundabout which forms Junction 47 with the M4 Motorway

M4 motorway

The M4 motorway links London with South Wales. It is part of the unsigned European route E30. Other major places directly accessible from M4 junctions are Reading, Swindon, Bristol, Newport, Cardiff and Swansea...

.