This image is a real problem for me. I REALLY want to like it - it has a great fairy tale quality, but I think it has too much post processing and not enough done "in camera." If I am wrong, I apologize.... It's still a very tale like submuission.
I very much like the composition of this shot, and certainly, the soft focus makes it look more painterly and whimsical, but it's hard to tell in spots what is meant to be soft focus and what is motion blur. Great concept.
Interesting effect - it kind of looks like an illustration - I like it. I think you could crop out the bottom third or so, to bring more attention to the bridge.
I'm a big fan of this soft effect, but it seems a bit overdone in this shot. I think the composition would also benefit by bringing the bridge down a bit into the frame. It's great that you were able to find a real-life subject for this challenge.