From Roader's Digest: The SABRE Wiki
|From:||St Clears (SN274160)|
|Length:||9.3 miles (15 km)|
|Meets:||A40, A477, B4299, B4314|
|Former Number(s):||A477, B4313|
|Route outline (key)|
The A4066 is an L-shaped road in south Carmarthenshire. It starts at a roundabout on the A40 St Clears bypass, where it also meets the A477. The road heads eastwards into town to meet a set of traffic lights where it TOTSOs right and heads south over the A40. This is actually a partial GSJ with east-facing slip roads and indeed through traffic on the A4066 has to TOTSO.
The road continues south through the town centre before crossing the River Taf to enter open country. It climbs out of the valley and continues downstream, reaching a summit before descending into Laugharne. It zigzags through the town's streets, which are frequently too narrow to allow of a centre marking. Passing the castle, we catch a glimpse of the coast before climbing out of town.
Now heading more west than south, the road passes along a small valley before descending onto the coastal plain. Initially the sea is too far away to be visible from the road. The route continues along the northern edge of the flat land, with steep hills to its right and the plain (with its firing ranges) to the left.
It goes through the village of Llanmiloe before reaching the caravan parks that welcome us to Pendine. The buildings soon become more permanent and we pass a brown sign for the Museum of Speed – Pendine Sands have often been used for land speed record attempts. We finally reach the coast, but not for long. The road very shortly turns sharp right, inland, and becomes the B4314, which takes us back to the A477.
On classification in 1922 the road from St Clears to Laugharne was the B4313 whilst the road from there to Pendine was unclassified. In 1935 the road was renumbered A4066, which also took over the road to Pendine.
Originally the A4066 started at the A40/A477 junction in the centre of St Clears. With the construction of the A40 bypass the A4066 took over the old road west out of town, which was actually the eastern end of the A477 (although it had been A40 for a few years in the 1920s).