Interpretation ID: aiam2550
Director of Engineering
Wayne Corporation
P. O. Box 1447
Industries Road
Richmond
IN 47374;
Dear Mr. Kurre: This responds to your December 10, 1976, petition to amend Standard No 222, *School Bus Passenger Seating and Crash Protection*. In your petition you request that the NHTSA withdraw the requirements for seat belts in buses with gross vehicle weight ratings (GVWR) of 10,000 pounds or less. Secondly, you suggest that the NHTSA reconsider the validity of establishing 10,000 pounds GVWR as the dividing line between buses that must be equipped with seat belts and those which need not be so equipped. The NHTSA denies your requested rulemaking.; The NHTSA mandated the installation of seat belts in school buses wit GVWR's of 10,000 pounds or less, because these vehicles are subject to different crash pulses than larger school buses under the same accident circumstances. To ensure adequate protection for children transported in these vehicles, the NHTSA applied to small school buses some of the seating requirements mandated for larger buses plus the installation of seat belts. Since we are aware of no data indicating that small buses do not need the additional protection provided by seat belts, the NHTSA considers the provision of seat belts in these school buses to be a necessary safety requirement.; The second recommendation in your petition suggests that the NHTS classification of vehicles into two groups, one with GVWR's of 10,000 pounds or less and another with GVWR's greater than 10,000 pounds, is arbitrary. You indicate that a vehicle weighing slightly more than 10,000 pounds will not react in a crash situation significantly different than a vehicle slightly under 10,000 pounds. Accordingly, you suggest that there is no valid reason to have different requirements for buses within a relatively narrow weight range.; The NHTSA has historically classified vehicles into the two weigh groupings you mention. This has been done in part because there are significant differences between large and small vehicles with respect to their reactions in crashes. The agency realizes that any line differentiating the two classes may seem arbitrary to manufacturers of vehicles that fall barely on either side of the line. Arguably, these vehicles, similar in many respects, would exhibit only minor differences in crash pulse in any given accident situation. Nonetheless, the classification is valid for the majority of vehicles in each class. Since we are aware of no data that would indicate that a line could better be drawn elsewhere, the NHTSA has decided to retain the present classification.; Sincerely, Robert L. Carter, Associate Administrator, Motor Vehicl Programs;