I don't like to judge other people's art, because art is in the eye of the beholder. Some art I like, others might not like.
Having said that, I do not find those particular pieces appealing.
I like the center street bridge. I think it's tastefully done (although it could use about 3 extra lanes on each side).
Why not complement it with a big archway, like an entrance way into the downtown core?
Maybe a dumbed down version of:
or