The former A4074 Narberth High Street
The original A4074 was a short link road between the centre of the Pembrokeshire town of Narberth and its castle, running along the High Street between the then-A40 and A478.
The A40 was rerouted through Whitland in the late 1920s and its original route through Narberth downgraded to become the B4314. The A4074 was downgraded at the same time to Class II status. It was part of the B4313 for some years but is now part of the A478 one-way system and is only accessible northbound.