Welcome to the forums. C&C per req:
1. Interesting persepective, might have been better from a slightly different position so that the sign behind his left shoulder was a little less prominent.
2. Too much going on in this photo; the eye doesn't really know where to go. Try and isolate your main subject through positioning and/or use of selective focus. As well, the flaring in this one is a problem too.
3. Good capture, has a nice, gritty, urban feel to it.
4. Nice capture, however it could have been improved by shifting your shooting position such that you were closer to the cars and zoomed in to a greater degree to eliminate the background