The road meets the M4 (the motorway that runs across South Wales) at Sarn Park services; it also meets the A4107 mountain road to Abergwynfi, the A4058 Rhondda Fawr valley road to Porth and Pontypridd and the Heads of the Valleys Road.
The road converges with the M4 (the motorway that runs across South Wales) at Sarn Park services; it also connects with the A4107 mountain road to Abergwynfi, the A4058 Rhondda Fawr valley road to Porth and Pontypridd, and the Heads of the Valleys Road.