With the exception of Sketty Lane itself, which runs from the seafront on Mumbles Road, Swansea, for some 950 m up the hill beside Singleton Hospital, the entire length of the A4216 is made up of the former northeastern end of the B4436.
The road commences at a signal-controlled junction on the A4067 Mumbles Road and runs north as a dual carriageway, which becomes a 4-lane single-carriageway road. At a mini-roundabout (where it meets the line of the B4436), the road bears right towards Sketty, turning right again at a set of traffic signals a short distance away.
At the next set of signals the A4216 crosses the A4118. The southern approach was widened in the late 1970s / early 1980s to make it a dual carriageway and there was at one time a proposal to demolish the Bush public house on the northern side of the junction to continue the improvement into Vivian Road. The proposal was to address traffic congestion at the junction. As an interim solution the right turn was banned from the southbound A4216 approach into the A4118. The interim solution has been in place for the best part of 30 years!
As the road continues north it passes a complex of three mini-roundabouts - the first a four-arm junction with Tycoch Road, and the second and third forming a TOTSO at Broadway / Cockett Road. The road becomes briefly rural in nature before arriving at Cockett. More traffic lights (with the B4295) lead to a bridge over the railway and a short hop to Fforestfach Cross and the route's terminus on the A483.