What Does It Mean When U See A Black Shadow On The Road?

Its not sure always sure that it's a ghost it may be the shadow of some item which are you not noticing , sometimes it may be illusion but in rarely cases depending upon the conditions and place it might be presence of god.

It depends on where you saw. It could be a long lost soul, drifting and trying to find it's way home or it could the guardian of the crossroads that you were lucky enough to catch a glimpse of. He is usually found at intersections.