Apparently, tests have proved inconclusive as to whether seatbelts on buses would help in the event of most accidents or not. The argument being, lap belts can actually cause more damage to the lower back and head without also having the shoulder restraint as well(not practical?). Buses are designed, for the most part, to locate the passengers ABOVE the likely area of impact(they say), however, there's always certain situations where these designs and arguments don't apply.

Half of communication is listening. You can't listen with your mouth.