They tell you to keep your arms and legs inside the ride at all time knowing riders will disobey because they've been taught that rollercoasters are most fun when your arms are in the air.
But Disney parks have a reputation for being tidy, orderly and accident free, so how do they protect themselves from those rebel riders who refuse to keep their arms inside the car?
They use this crazy looking contraption called the “envelope of protection”, which is covered in small pieces of wood that approximate the farthest points a rider can reach out on all sides.
If any pieces are knocked off during the coaster's run the ride's safety engineers can locate the problem spot and help prevent future limb loss.
-Via LAist