I don't know if it's geographically true for most campuses, but for my school (in the city) we have buildings located at places where there are restaurants, bars etc, nearby.
Our school has a similar bus system, but they would ONLY pick up and drop you off on campus buildings. So in a sense, you can go to a restarant then being picked up by the bus nearby in front of a school building. In that case, it would "sound" like the school is not encouraging underage drinking of all sorts. Just making sure that students get from building A to B safe.
of course, afterall, that doesn't stop people from drinking. But in this way, the school will feel they are not responsible for anything that happens to the student. But I do see another dilemma as to whether the bus driver will take the student or not....
