This article is about the B4279 that ran in South Wales that was quickly upgraded to the A4093.
For another road numbered B4279 near Chippenham in Wiltshire, see B4279 (Wiltshire)
(former B4279) crossing the River Ogmore
The B4279 was originally allocated to the road between Tonyrefail and Blackmill in South Wales. At the time of road classification, this was the main road to the Rhondda Valley from Bridgend and Swansea, and hence it was one of the first roads to be upgraded to class I - in this case to A4093, probably on 1 April, 1924. The road remains this number, although Tonyrefail has been bypassed and so the eastern end of the former B4279 is now part of the B4278.