Someone struck by a car leaving the fast food place most likely cannot sue the fast food place, since the law does not specifically require such signs in these locations. To sue, the would-be plaintiff would have to prove, using expert testimony, that it was unreasonably dangerous to not put up such signs. This can be difficult and expensive.The driver of the car pulling out definitely could not sue in any event, since he or she was liable (careless) in not looking first before pulling out, and to only pull out if the "coast is clear." Signs or not, a driver is obligated to exercise care; if a driver fails to do so, that failure will prevent him or her from recovering money, since  people may not profit by their own negligence.