Revisiting places or viewpoints that I have been to many times is an old habit and I often get jokes from fellow photographers about photographing the bridges yet again!
The reason is simply because, there is always something different to capture. No matter how many times I visit, the conditions and quality of light usually means you are able to get something a little bit different, whether it is the colours in the sky, the clouds, the tide, time of day/year and often combinations of lots of other smaller factors.
The other challenge is of course to try and push yourself to come up with something a little different than last time.
All that said, these bridges are very much a part of Dundee, old and new.