The road measures 11.29 miles long and would take a car obeying speed limits 17 minutes to travel its length.
The B4577 is a B Road and is located in the Zone 4 Highways Region.
This is a true long-distance route, journeying through numerous towns like Aberarth, Pennant, Cross Inn, Bethania, Penuwch, Llangeitho, Blaenpennal, and Tynreithyn.
The road connects Dyfed and Dyfed.