LiveForTheLaunch said:and also because of the fact that my stepdad (he's over six feet tall) went on a coaster at the fair last summer and the guy didn't check his height, and his head almost hit off of one of the supports. He actually had to duck to avoid them!
What kind of coaster? Travelling coasters are designed the same way park coasters are. They are tested for height clearances before being sold/opened.
The only coaster I've ever had a problem with is the Mouse at Blackpool. There's one support over the lift where it brushes my hair if I'm sat upright. If I was anything over six feet tall, it would catch my head.
On other coasters I've thought I may hit my head, but the clearance is actually much more than you imagine. I still duck, even knowing that I can't hit the supports (hence the reason it's called a "head chopper" element).
Unless it was a tiny kiddy coaster, there's no way he'll have actually been in danger. Though a Kiddy coaster should certainly have an enforced maximum height limit - though it's difficult to imagine anyone over six feet tall physically getting into one of those carriages