wizdum:
I drive through crowded areas every day on my way to class. At any point in time, I could turn the steering wheel 10 degrees and murder no less than 25 people in less than 3 seconds. I could crash into a school bus and kill 20 - 100 children in less than one second. What could be easier than that? What keeps me and billions of other drivers from doing this every single day?
From some of the terrible accidents I have seen on the news, I would say you are greatly overestimating the damage of these collisions. Not that they are good in any way, but even the worst ones end up with a few dead and many injured. Especially with the bus, unless you end up sending it over a cliff. Busses are well built, and even in roll-over accidents the kids almost always survive, mostly with psychological injuries. Maybe it's because they are all young and light. No 300 pound lady to land on you in exactly the way it would happen on a MegaBus. 