The road measures 14.49 miles long and would take a car obeying speed limits 25 minutes to travel its length.
The A4109 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 Aberdulais, Cilfrew, Crynant, Seven Sisters, Onllwyn, Dyffryn Cellwen, Banwen, and Glynneath.
The road is located entirely within West Glamorgan.