The road measures 15.40 miles long and would take a car obeying speed limits 32 minutes to travel its length.
The A4139 is a A Road and is located in the Zone 4 Highways Region.
This is a true long-distance route, journeying through numerous towns like PEMBROKE, PEMBROKE DOCK, Lamphey, Hodgeston, Jameston, Manorbier, Lydstep, Lydstep Haven, Penally, and TENBY.
The road connects Dyfed and Dyfed.