I work in an adjoining county than my games, so "round trip" numbers would be really out of whack for me. Numbers are from my home.
Varsity: avg is 30 miles from my home.
Some closer at 6 miles, some further at 40 miles. We have a few schools 90 miles from my home.
For anyting below Var, the assn tries to keep us close to home. So avg from home is 7-10 miles for anything besides varsity.
No matter where the school is, we get a flat fee of $15 to travel. Since some schools are close & some far, the travel works out to our favor at the end of the season.