Color! The BW is flat. There are ways around that. The rust color pops from the rest of the frame. I do not think BW could capture that effectively. Seems like it was shot midday. Maybe try some when the light is softer and more directional.
That's all right. You can remember this shot next time you roll up to a rust spot. Personally I am fascinated by rust and shoot it a lot. I think it is the whole; weather and the natural order of things will eventually transform and or destroy anything.
Deffinatly the color version. The B&W, is flat, and while the cracking paint is more pronounced in the B&W I feel that that rust makes a better subject.