The A4232 forms three quarters of an outer ring road of Cardiff, with the M4 completing the circle to the north, thus connecting Cardiff Bay and the docks with the motorway in both directions. At least that's the theory. Whereas the western half of the A4232 seems to be complete, the eastern half of the road consists of two short unconnected link roads.
Cardiff West - Cardiff Bay
The western end of the A4232 is at M4J33, which also serves Cardiff West services but no other roads. Initially we head south, as a grade-separated trunk dual-carriageway through open countryside. Southbound there's an unexpected LILO junction which only serves the Museum of Welsh Life at St Fagans; there's no corresponding northbound link so traffic is signed to rejoin the southbound A4232 and then U-turn.
Over a mile later, having crossed the main railway line and the River Ely, we reach the first actual GSJ on our route at Culverhouse Cross, where we meet the A48(for west Cardiff) and A4050 (for Barry and Cardiff Airport). Although there's little on the ground to indicate our change of status we lose primary status here. The road then heads east, skirting the edge of the urban area, to recross the River Ely and meet the B4267. Heading south now, we cross the river twice more in quick succession, going over the A4160 with no junction, and then bend to the left to meet the A4055. We then cross a long bridge over the River Taff on the northern edge of Cardiff Bay. There's a turn off for Butetown and the Bay area and then we drop down into the Queen's Gate Tunnel. We soon emerge and cross a roundabout with the A4234. We continue onto a newer stretch of road – the A4232 Ewart Parkinson road, which opened in June 2017 – and reach a large roundabout where the A4232 classification disappears.
Cardiff Bay - Cardiff Gate
Plans for the unbuilt section of the A4232
To continue following the A4232, we turn right at the roundabout onto the unclassified Ocean Way, and immediately turn left at another roundabout onto the unclassified Rover Way. We continue along this road through an industrial area, going through two roundabouts before bearing left, passing a Tesco, and reaching another roundabout. Perhaps unexpectedly, the A4232 reappears here (there are no other classified roads), with splayed carriageways on that road suggesting a possible future GSJ. We cross the River Rhymney twice in quick succession, with the main railway line in between, meaning that the majority of this section is elevated. It's also S2, meaning that dualling could be expensive.
As soon as the A4232 has appeared it disappears again. We go over a roundabout on the A4161 and then that road comes up to merge with us and we take its number. We're now dual again. There are a couple of bends and we come to a halt on the A48. There's a multiplex east along that road through the bi-central suburb of Llandeyrn and the A4232 reappears at the second GSJ. We're now dual once more but there is an at-grade roundabout we have to stop for, serving a retail park. The road continues north to end at the next roundabout, M4J30. It's a similar junction to the western end: just the motorway, the A4232 and a service area, Cardiff Gate services, although this time there is an unclassified road heading north to nowhere in particular.