"non compliant vehicles will be turned away" At which point the vehicle will perform a 3 point turn (involving reversing) thus negating all apparent safety benefits, in addition to having to make the same journey again doubling the chance of an accident. The genius of health and safety.,(reply>), @quillaja I know that's a joke, but it would be physically impossible for humans to make the sound those trucks make IRL.,(reply>), The guy in the non-compliant truck will just lean out the window and say "SHHHH SHHHH SHHHH".,(reply>), Not if they've pulled up beside the gate, and the guy responsible for opening it leaves it closed unless the driver can shift into reverse and demonstrate the sound. If the truck beeps, it's sent away... moving off in a forward direction.