USA Bus Lines - How old do you have to be to travel on a charter tour bus? Do you have to be a certain age to go alone?

How old do you have to be to travel on a charter tour bus? Do you have to be a certain age to go alone?

Me and my friend want to go on a charter bus tour and I want to know if you have to be a certain age to go without a parent with you?

I think it depends on the company but the basic rule is 16 years old without an adult to go alone