Originally Posted by aeh
It's also the height at which one may ride in a car in most states in the USA without sitting in a booster seat.

Funny I just had to take ds9 out of a booster seat because he was too tall for a full seat and above the weight rating for the half seats - plus they were too narrow. He is not 4 ft 9 and he is not a fat kid either just deep chested and solid.