|Location Map ( geo)|
|Distance:||4 miles (6.4 km)|
|Route outline (key)|
The B4280 is a short rural road across Hirwaun Common near Bridgend.
The route starts in Bryncethin at a roundabout on the A4061 and runs eastward across Hirwaun Common. In Heol-y-Cyw it reaches a T-junction where it turns right. From here it continues to its terminus at a roundabout junction with the A473 east of Penprysg.
The final kilometre of the present road, taking it out to the Pencoed bypass is new build; the B4280 originally ended on the pre-bypass line of the A473 in Pencoed,