The B4625 is a Class II road dating to the 2010s in the lower Swansea Valley north and north-east of Llansamlet. It serves the development area known as "Swansea Vale", which comprises the Riverside Business Park, the Central Business Park, Tregof Village, and sites at Llansamlet East and Peniel Green.
Starting at a grade-separated junction with the A4067 at Tircanol, north-east of Morriston town centre, the road heads east-southeast past the DVLA's Swansea offices to a terminus at the Lôn-las interchange (Junction 44 of the M4), where it also meets the A48, the A4230, and the B4291.
The route number, although referred to in Local Authority documentation, does not appear on any road signs.
