|To:||Tredegar House (ST283859)|
|Distance:||1 miles (1.6 km)|
|Met (1923):||A468, A48|
|Now part of:||A468, A467|
|Route outline (key)|
Along with the original B4243, the B4242 was renumbered A4072 in 1935. This route was then dualled, mainly on-line for this southern section, and has since become part of the re-routed A467; the northern end of the ex-B4242 is bypassed and so is part of the A468.