This picture appears in the 1995 South Wales Argus publication "IMAGES
The caption under it reads 'Pedestrians may safely pass over Caerleon
Bridge after the opening of a footbridge alongside in 1968'. This is
true, of course, but a closer look at the photo reveals that the footbridge
is on the wrong side of the old bridge! Clearly it has been superimposed
on an old photo.
Presumably the planners looked into the options of placing the footbridge
upriver or downriver of the old stone bridge.