|Location Map ( geo)|
|Distance:||12.8 miles (20.6 km)|
|Meets:||A4043, B4248, A465, A4077, B4269, A465, A4143, A40|
|Former Number(s):||B4247, A465|
|Route outline (key)|
The B4246 is a road of two halves in north Monmouthshire.
The first half starts on the A4043 in Pontnewynydd, and parallels that road through Abersychan (where it crosses the A4043 at a staggered crossroads) and Varteg into Blaenavon, where it meets the A4043 for a third time, at that road's terminus.
After Blaenavon, and a meeting with the the B4248, the road changes character and winds uphill, before a great view of the Black Mountains unfolds in the distance. From here, it's a sharp descent through woodland and some crazy hairpins down to a T-junction with the route formerly followed by the A465 Heads of the Valleys Road, in the days before construction of the Abergavenny southern bypass.
Both onward directions from here are now sections of the B4246: the left branch running for 2 km westward through Gilwern to meet the present A465 at the Glanbaiden Roundabout, and the right branch for 2 km eastward to meet the same road at the grade-separated Llanfoist Junction. This latter branch does eventually reach Abergavenny town centre, following Merthyr Road and ending on the A40, but not before being interrupted by some 600 m or so of the A4143, which carries the route across the River Usk.
The B4246 was originally just a short link from the A4043 near Abersychan into the town centre. By the mid-1920s it had been extended in both directions along previously unclassified roads, south to Pontnewynydd and north to Varteg, where it still ended on an unclassified road. It was then extended along a further unclassified road (possibly as part of an online upgrade) to Blaenavon and from there along the former B4247 to Govilon, probably in 1935. The latter part of the route, after it splits in two, follows (as mentioned above) the pre Abergavenny southern bypass route of the A465.