HUNTSVILLE (KFSM) -- Following Monday morning's (Sept. 21) deadly accident between an SUV and a Huntsville school bus, some 5NEWS viewers asked why school buses do not have rear under-ride bars like those on the back of semi trailers.
A rear under-ride bar keeps smaller vehicles from driving under a much taller trailer during rear-end collisions.
The rear under-ride bar is not part of the design of a school bus. Stan Andrews, the director and accident reconstructionist at Ei Consultants, LLC in Farmington, said it has to do with the break-over angle of the rear of a school bus.
"They do not want a rear under-ride guard that is going to cause the bus to drag and hang up because the rear wheels are so far forward," Andrews said.
Andrews said without a rear under-ride bar, vehicle safety systems designed to protect the driver and passengers do not work properly during a crash.
"The school bus has a relatively high bumper, which will miss the bumper region of a passenger vehicle," he said. "If they were equipped with rear under-ride guards then the bumper portion of the passenger vehicle would come in contact with the rear under-ride guard of the school bus."
But Andrews said that would change the way the bus is affected by the impact of a crash.
"If it has a rear under-ride guard, it is going to push the bus forward," he said. "There will be more forces applied to the bus."
And that, Andrews said, may have other unintended consequences for a mode of transportation that according to Charlie Hood, the executive director of the National Association of State Directors of Pupil Transportation Services, is safer for children than most others.
"School buses are far safer than the other ways kids get to school," Hood said. "On average there are about four to five passengers who are killed each year in a school bus crash compared to 4,500 who die in other modes during school travel hours."
Hood said currently, rear under-ride bars are not being considered as a requirement for school buses.