For school buses, how safe is safe enough?

The tragic school-bus accident in Alabama this week is bringing to the fore an ongoing and passionate debate about whether the nation's school buses should be required to have seat belts.

Four students died and about a dozen were sent to the intensive care unit after the Huntsville City Schools bus plunged off an overpass on its way to a vocational training center Monday. The National Transportation Safety Board (NTSB) is investigating the accident, which local police say may have happened when a compact car driven by another student either got too close or cut the bus off.

Advocates of safety belts on the ubiquitous yellow buses say this accident is proof that the nation is failing to properly protect its children by not requiring buses to have seat belts (something required of the family car). Opponents say that the buses' current design – with high, padded seat backs and emergency exits – are safe enough, and that certain types of seat belts, like a simple lap belt, could even be harmful.

Nonetheless, even before the crash, the NTSB had put school-bus safety on its list of most-wanted safety improvements.

The National Highway Traffic Safety Administration (NHTSA) has chosen to take a neutral stand. "In a report to Congress about the value of belts on buses, the conclusion is that ... shoulder belts could have a marginal impact on safety," says Rae Tyson, an NHTSA spokesman. "So we've left that decision up to the state and local governments."

Currently, only a handful of states now require safety belts: New York, New Jersey, Florida, and California – and some of those states even leave the decision up to the local school districts.

Opponents say that requiring belts simply adds to the price of transporting students, without a corresponding increase in safety. There's not only the cost of installing the belts, but also the expense of buying extra buses. Currently, buses without belts can seat three students to a seat. With belts, that number drops down to two a seat. So, requiring seat belts would also require a third more buses. And because so few fatalities are associated with school-bus accidents, opponents say it's a poor use of resources.

According to the National Academy of Science's Transportation Research Board, each year approximately 800 school-age children are killed in motor vehicle crashes during normal school travel hours. On average, about 20 fatalities – 2 percent – are school bus-related. Five of the fatalities are school-bus passengers, and 15 are pedestrians. The rest of the deaths occur in private passenger cars and to pedestrians, bicyclists, and motorcyclists.

"There are not that many fatalities on school buses, thankfully," says Bill Hall, manager of the occupant protection program at the University of North Carolina's Highway Safety Research Center in Chapel Hill. "Bottom line is that school buses in and of themselves are extremely safe vehicles."

But seat-belt advocates say those statistics are misleading. There may be few fatalities, but there are serious injuries that could be avoided. Last month, the Journal of Pediatrics found that annually, 17,000 serious injuries on school buses required a trip to the hospital. "Those injuries are unnecessary and could be prevented and need to be prevented." says Dr. Alan Ross, president of the National Coalition for School Bus Safety in Torrington, Conn.

Ross argues that seat-belt technology has advanced so much over the past 30 years that any questions about the belts' safety have been addressed and they should be standard operating equipment.

"Today, every child is pretrained to buckle up, and then when they get to kindergarten they get on the bus, and they wonder, 'Where's the safety belt?' " says Dr. Ross. "And then we wonder years later, why these kids are dying ... as teenage drivers.... What we're finding is that they're not wearing their safety belts. Where did that negative training come from?"

Dr. Hall agrees that buses would be safer with belts, but he is also quick to point out that even without them, school buses are still the safest way to get to school.

"The children who were at most risk were those who were being driven back and forth by their parents, or even worse, their older siblings," he says.