THanks all.
When I first popped the lens cap off, I was thinking the picture would be about the structure of the bridge. You are all quite right though that the light and graffitti at the end (the "stained glass") are much more interesting ideas, and that a tighter crop suits, especially at the sizes that pictures get displayed here.
Here's the "cathedral crop" -- I have a couple of shots with no cars, I'll go back and look to see if they are sharp enough to do something with.
Thanks,
EL