It's quite surprising to learn that there were plans for a Newport bypass as early as 1933. Above, we can see a section of a large map of the Newport area showing how the planned new road would skirt Caerleon.
Basically the road started at roughly where the Tredegar Park Roundabout is nowadays. It followed the route now taken by the motorway as far as Kimberley Park. Tunnels were obviously not considered a practical solution so the road then ran up Malpas Pitch as far as the Three Horseshoes Pub. It then ran around the back of Lodge Hill (as seen above) to join the Ponthir Road just outside Caerleon. Just before entering Caerleon it turned left to cut across to the Usk Road. Instead of turning sharply by Twyn Oaks, it carried on straight across the River Usk and the land now occupied by the Ryder Cup Course. (In fact the bridge crossed the river at the same spot as thenew Ryder Cup Bridge.) It carried straight on and through the gap in the hills where the present A449 runs, finally meeting the Chepstow Road by the New Inn.
To examine the whole map visit the Newport Past Website.
By 1949 it had been decided to build a Severn Bridge and a new Motorway that ran around the North of Newport. Even then it was recognised that this was not the ideal solution and a Southern bypass, in addition, was also envisaged. Incidentally, in the document South Wales Outline Plan published by HMSO 1940 it states:
The present highway from Newport to Caerleon along the southern bank of the Usk, leading to the old bridge, is a very awkward one, and cannot be satisfactorily improved because of restrictive levels and surroundings. We have, therefore, recommended a new by-pass route along a line following the railway to the north of Caerleon, crossing the Usk by a new bridge, and making connection with the motorway near St. Julians Brickworks. This route actually shortens the distance of the present unsatisfactory access to Caerleon, relegating the old town to a quieter "precinct", which will be much more seemly than for such a place to be disturbed as it now is by the claims of through traffic. (Paragraph 261, page 70)
But that's another story!
The building of the Ryder Cup Bridge
Caerleon Bypass Plans 1959