The A6123 is part of the Rotherham Ring Road. The route came into being in the mid-1930s running purely between the A631 and A630 and has been extended anticlockwise over the years.
The road starts at the Worrygoose Roundabout, where it meets the A631, and heads north along the residential Herringthorpe Valley Road. Although this road is S2 it has very wide verges suggesting something larger may have been planned. The A6021 is soon crossed at another roundabout and we continue north through Herringthorpe. Presently the road becomes even wider – with service roads on both sides – but remains S2 until, just before the Mushroom Roundabout, we gain a central reservation, which has the effect of making the road seem narrower.
We cross the A630 and the road narrows again to cross the River Don and enters an industrial area. The A6123 is now narrow enough to be a genuine S2 road. We bear round to the left and go under a railway bridge, followed by two adjacent railway bridges just afterwards. There's a roundabout providing access to a retail park which we then pass on the D2 Great Eastern Way, soon meeting the A633 at the next roundabout.
The A6123 continues west, now single-carriageway once more, passing through an area of light industry. The road soon bends to the left to cross a stream then winds through an industrial estate to a roundabout where it meets the B6089 and turns left. The road is dual as it heads south under a railway line but then loses the central reservation as it bears right. We continue for a short distance further before our journey ends at a roundabout on the edge of Rotherham town centre, where we meet the A629 and A630.