However , the dualling of the A48 Neath bypass was only completed in 1960 , with the A48 ( M ) Port Talbot bypass following in 1966 .
Proposals for a high - quality new road across South Wales were first made in the 1930s .
The dualling of the A48 Neath bypass was only completed in 1960 , with the A48 ( M ) Port Talbot bypass following in 1966 .
Proposals for a high - quality new road across South Wales were first made in the 1930s .