|Location Map ( geo)|
|Distance:||13.9 miles (22.4 km)|
|Meets:||A4119, A4058, B4512, B4275, A4059|
|Route outline (key)|
The A4233 is very much like the A4061 in that it links up several settlements along the Rhondda Valley, and goes over some scenic mountains on the way. The terrain is not quite as forlorn as on the other road, with the exception of the final descent into Aberdare.
The road starts at a roundabout junction with the A4119 north of Tonyrefail and heads uphill to Trebanog, before winding back down the other side to Porth, where it meets the A4058. There's a short multiplex with that road (although some maps claim it's with the A4225 instead) before the A4233 regains its number and runs along a new relief road that heads up the Rhondda Fawr for a few miles before meeting the old road at a roundabout and carrying along it through Ferndale up to Maerdy.
Here, there's a TOTSO to the right (ahead is unclassified) and the road leaves its urban surroundings and heads up the mountains towards Aberdare. The uphill ascent is relatively straightforward, but on the other side of the mountain there's a sharp series of multiple hairpins to negotiate before the edge of the town is reached. There's then a short run downhill and the road passes through a one-way system in the town centre before bearing right at a roundabout to end at another on the A4059 eastern relief road.
Most of this road has been the B4277 at some point.
Originally, that road ran from Porth to a dead end at Maerdy. The extension to Aberdare was built at the start of the 1930s as an unemployment relief project, along with parts of the A4061 and A4107. In 1935, the road was then extended south towards Tonyrefail using part of the B4278.
The upgrading to A4233 occurred in the late 1980s when the existing road was diverted from Trebanog downhill to meet the A4119, avoiding the centre of Tonyrefail.