Cloud chasing

This morning on my drive to work I noticed on the road ahead a clearly delineated shaded area although there are no trees or buildings along the road. That's when I realized that the shadow was cast by a cloud. I drove on toward it hoping to get away from the hot sun. However as soon as I reached the shaded portion, it seemed like the shadow dissolved and I couldn't tell whether I was in the shadow or not. Then farther down the road I spotted the end of the shadow and some seconds later I was back out in the sunshine.