Do they really exist, or are those who experience paranormal issues under some hallucination ? It has happened to me on more than one occasion.
On my drive home over weekends I have to pass a very lonely stretch where a gruesome murder had taken place many years back. I used to drive at night till advised not to. At this particular area a white figure crossed the road very quickly. Whether real or not is the issue. Had to press on the gas with a look at the driving mirror whether still visible or even in the back seat.
No more driving in the night. God Bless