Although most people would have the same healthy fear of driving off a 50-foot cliff as they have of falling from a five-story building, most aren't afraid to drive 40 mph, and many overestimate their chances of surviving a crash at that speed.
A car travelling 40 mph would strike a tree, a wall or a bridge abutment with the same force as a car hitting the ground after falling off a 50-foot cliff. An unrestrained occupant within that car, moving at 40 mph, would strike the windshield or dashboard with the same force he or she would experience hitting the ground after a fall from a five-story building.