The A4223 is a short urban A-road in Pontypridd, linking the A4058 with the A470 north of the town centre. It is essentially an upgrade of the former B4274.
The road starts at a gyratory in Pontypridd town centre, one that's sufficiently large that the Rhondda River runs through it and two railway lines meet in the centre. The A4058 also passes through. We head north along Gelliwastad Road, a straight road lined with old buildings. We bear gradually round to the right and meet the B4273 at traffic lights just past the bus station.
The road then crosses the River Taff adjacent to the old steeply humped bridge (a pioneering river-crossing in its day – it was completed in 1756 – but replaced in 1857 by the present bridge, much more suited to the requirements of wheeled traffic). We then bend first right then left to reach another roundabout, a grade-separated junction with the A470, where the A4223 ends. Continuing east from here is Coedpenmaen Road, a branch of the A4054.