A small truncated school bus or mini bus body on a small truck frame. Usually used to transport mentally challenged/retarded folk wearing hockey like helmets. Usually travels well under the speed limit on major highways. Usually the "special ed bus." Many times, a half loaf bus passengers are drooling out the windows.
Small stunted school bus almost exclusively used in transporting special needs people. Also known as "the short bus." These half loaf busses look like half loaves of bread.