You were traveling to and from what was essentially a school function right? Kind of like an extended field trip. There's a reason why schools don't just hand the keys to the buses to any wide-eyed-pizza-face when he needs to get somewhere.
It might seem dumb, but what would the court (or public) think when it finds out the teenager who careened over a guardrail into oncoming traffic did so at the request and direction of his school? They'd probably say "well gee, if only this idiot were being driven by a parent or an experienced driver, certified to transport students, this may not have happened. Here's your million dollars in punitive damages".
legally though he was the same as any adult driving me down their, plus if that was their policy it would of been nice for them to tell US that before we left, the only thing we were told about transportation from our town to dayton was that we would have to provide it ourselves, whether that was through an adult or ourselves they did NOT specify.