Good selection of shots, and as you put it under the heading of urban i guess thats the idea you were going for and the one that screams urban to me has to be the last one number 6, it shows a lot of things, litter, movement, metal, concrete the nuts and bolts of urban architecture. I like the country and the feel of being stuck behind a cage is very urban to me and that is the feel i get from the shot. Number 4 gives me a similar feel but to me just lacks what 6 has and its not just colour.
I think you have some good strong lines throughout the series. To pick a least favourite i would say number 3, for me there is just a little bit too much going on, maybe a portrait shot may have been good, along the same lines as number 5 just to get rid of some things around the edge.