From Roader's Digest: The SABRE Wiki
|From:||St Clears (SN274159)|
|Length:||22.2 miles (35.7 km)|
|Meets:||A40, A4066, B4314, A478, B4586, B4318, A4075, A4139, B4325, A4076|
|Former Number(s):||A40, B4324|
|Old route now:||A4139|
|Route outline (key)|
I've not yet managed to figure out the A477. Some of it is primary, some of it not. The bit that isn't is possibly the most strategic part of the route - the Cleddau Bridge near Neyland. There are alternatives to most of the A477, but the alternative to the Cleddau Bridge is a 40-mile detour via Canaston Bridge and Haverfordwest on the A40.
St Clears - Johnston
The A477 starts at a roundabout at the end of the A40 St Clears bypass. The roundabout is significant as it marks the end of the dual carriageway route from London (and much of the rest of Britain). The A477 heads south-west along single-carriageway road via Red Roses towards Kilgetty, passing through wooded countryside. At Red Roses, a left turn along the B4314 leads to Pendine Sands, which was the site of various land speed record attempts. At Kilgetty, we reach the boundary of the Pembrokeshire Coast National Park.
Kilgetty itself is bypassed - the road passes through a rock cutting and under a concrete arched bridge before arriving at a roundabout with the A478. A left turn takes you towards Saundersfoot and Tenby, a right takes you towards Narbeth, and eventually towards Cardigan if you stay on it for long enough. The A477 itself continues straight on towards Carew Castle, passes to the north of Pembroke (as it always has) then to Pembroke Dock where it once terminated. Now, the road continues towards Haverfordwest by crossing the Cleddau Bridge (Toll), built in the 1970s and replacing a ferry. The road ahead was the B4324 for many years but finally became the A477 not long before the bridge opened.
The route terminates on the primary A4076 linking Milford Haven and Haverfordwest. I still don't understand why the Cleddau Bridge section of the A477 is not Primary.