Ever wonder why amusement parks use height limits? Why measure height if what they want to get at is age? Well, in some cases height limits are appropriate, when they relate to the restraint system and seating used in the ride. If the rider is too small or too big, they might not securely fit in the restraints. Otherwise, it is merely a proxy for what they really want to measure, psychological traits. Why do they still use it? Because height is very easy for a ride operator to measure. Psychology, not so much.
20180524/DuckDuckGo amusement partk minimum height
20180524/https://saferparks.org/safety-tips/minimum-height-restrictions
20180524/https://web.archive.org/web/20171105130220/http://www.heightrequirements.com:80/rides/cedarpoint