Be This Tall to Ride (opens in new tab)

There's a measuring post at the entrance to the Cannonball Express, the old rollercoaster at Pleasurewood Hills outside Lowestoft. Clear the line painted on it and you ride; fall short and you don't. Nobody argues with the post. The physics of the ride set the number, the number isn't negotiable, and being turned away isn't an insult. It's just maths about restraint systems.