In our local district, rather than have individual buses for elementary, middle school, etc., they are having one driver pick up the elementary kids, drop them off, the go back out and pick up the older kids. They had to change the start times for elementary and high school to make this work, and they're also paying the drivers more, but it seems to be working. One issue is that if a single driver goes down (illness, etc.) it's a huge hit to logistics, and subs are hard to come by. But mostly they've made it work.