The Short Bus

While driving into work yesterday I spotted a short school bus, which got me thinking:

"Why is there more than one design for school buses?"

If you aren't familiar with school buses there are at least three different designs.  You have the "standard" school bus, the short bus (which is just a mini "standard" bus), and the "snub" nose school bus.  Who would have thunk that the school bus could have so many different forms?

The major goal of a school bus is to transport kids, which the "standard" bus does to perfection.  In school bus design you can't get much more exciting than that.  Pile a bunch of kids into a hollow tube with wheels and an engine.  Simple, right?  Apparently not as simple as I thought.

Do any of you know of "other" school bus designs, perhaps I missed one?  Is there a need for a handful of different school buses that I just don't know about?  What say you?