First, motorcoach travel rivels air travel when it comes to safety. Second, a 3000lb car vs a 20 ton bus is quite a mismatch. Basically a speed bump, not likely to cause much harm to the bus passengers. Keep in mind, bus accidents are very rare.
EXACTLY.
Except in the very very rare case of a rollover, bus passengers will hardly notice it if an accident occurs. I not only speak of physics, I speak from experience.
When 2 cars hit, a tremendous amount of kinetic energy is transfered from one vehicle to the other -- basically, the cars (which weigh nearly the same as each other) and all of their contents (including humans) go BOOM.
When a car and bus hit, the huge mass of the bus absorbs all but it little smidge of the kinetic energy transfered to it from the car. I like localdriver's analogy of hitting a speed bump. The energy just doesn't get transfered to the passengers, and consequently the passengers don't get thrown or even substantially jostled. I remember being in a car vs. bus accident when I was in middle school. A car was merging into our lane (we were on a highway) and smashed into the right front of the bus, near the door. I swear, I thought we hit a pothole at first. The car was in terrible shape, but there were no injuries on the bus.
Think of 2 toddlers running into each other at full speed. They'll both get hurt or at least momentarily stunned. Now think of a 20 pound toddler runing full speed into the beefy leg of a 200 pound man. The kid might be hurt and will be stunned, but the man will hardly be affected by it.
On a slightly different note ... not to try to get morbid for a moment, but I remember a well-publicized bus crash in Alabama last year -- a bus with about 36 people drove off a 30-foot-high overpass and I think 6 people died. I am not minimizing the tragedy for the affected people and their families and friends. But looking at the numbers, 1 in 6 passengers died. Imagine a car or SUV driving off a 30-foot-high overpass ... I seriously think that more than 1 of those 6 people would die in such a plunge.
I could go into more detail with some stuff, but I'm beginning to bore myself, so I can just imagine my affect on you right now ....
Every year, millions of parents trust the safety of their millions of precious children to the buses and bus drivers associated with Walt Disney World. Come join the club!