|To:||Narberth Castle (SN108148)|
|Length:||0.1 miles (0.2 km)|
|Now part of:||A478|
|Route outline (key)|
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.