The A5154 is the original western end of the A5, from Holyhead station to the old port and ferry terminal. Since the port access has moved to the east of the station, the class I classification is largely redundant as it just serves the nearby local area.
The road starts at traffic lights at the western end of the North Wales Expressway, where the A55TOTSOs right to cross the railway line. The A5154 continues north along the S2 Victoria Road. It passes the station and associated railway lines on its right and passes under the pedestrian Celtic Gateway Bridge. The railway line peters out and its wall is replaced by a metal fence which is the boundary for the port. The A5154 continues on to Marine Square where the road bends round to the left into Prince of Wales Road. The A5154 ends here, with the road ahead unclassified. The continuation of Victoria Road now just leads into a car park followed by a locked back gate into the port; however, this was once the A5 and the main route to the port.