I remember that bridge. It was handy for a walk and I missed it when it was dismantled. I also recall Riverside Drive being built. My uncle was employed on that project. The houses were very close to the river. Maybe there were flooding problems. I moved away and took little interest, so this is pure speculation.

That's interesting - as I recall, the weather & a few other things [supply problems, perhaps] delayed the building of "our" section of Riverside Drive, and a couple of the neighbouring roads.

Not that close ! but our houses were quite some feet about the top of the river bank and no flooding problems that I'm aware of for this area. The bank to the other side [farmland] might have been lower ... and the banks were lower again "in the town".
I did manage to pick some lovely blackberries from bushes in the cutting leading to where the bridge was.
I recently visited the area, and was interested to see that the cycle route to Calne has a replacement bridge, and another at the Black Cat.

I had a Saturday job at the "new Library" opposite the Bus Station for a couple of years, before becoming a student at a college in the Midlands.