Why aren't carseats required on buses?

[my3peanuts]

I don't understand this. My dd will be 5 next year and going into kindergarten. There's no way she'll weigh enough to be out of a carseat and yet the buses around here don't even have SEAT BELTS! How do they get away with that?

[ThreeBeans]

The way buses are designed, the 'compartments' created by the seats are supposed to act as the restraint. Definitely not as safe as a five point harness of course. The argument is that buses statistically are far less likely to be in collisions than autos.

There is also the counter argument that the 'compartment saftey' thing only works on people of a certain height or weight. (I'm not recalling the figures off the top of my head, but they're definitely larger than the average kindergartner)

Personally, I would not be comfortable putting such a small child on a bus every time, but it is of course a parental decision

[dallaschildren]

I understand your concern. Buses are the safest form of ground transportation. Why? Buses are larger and heavier than most vehicles, crash forces are distributed differently (evenly), the occupants experience these forces differently, they are statistically the lowest "risk" mode of travel, and they are conspicuous as hell.
In addition, buses are designed with the theory of "compartmentalization" which combines energy absorbing seat backs, and narrow spacing between occupants which offers a "compartment" size space for the occupant. It provides passive protection. Think of an egg in a carton.
With that said, there is a push by NHTSA and others to mandate seat belts in buses. When or if this will become law, I don't know. There is a small percentage of bus companies/school districts who use/manufacture buses with lap and shoulder belts in them, right now.