NTSB safety recommendations are issued as a result of its investigations of transportation accidents, incidents and safety studies conducted by the Safety Board to improve Transportation Safety. When these recommendations are not implemented, transportation safety continues to be at risk.
In its 1999 special investigation report on bus crashworthiness, the NTSB found that compartmentalization, the method of occupant protection developed for school buses, does not protect all passengers in all types of vehicle impacts and rollovers. Although the NTSB concluded that because of compartmentalization, school bus passengers were safer than they were prior to landmark legislation introduced in 1977 requiring significant changes to school bus vehicle design, compartmentalization is incomplete in that passengers do not always remain completely within the seating compartment throughout all accident sequences. The NTSB recommended developing standards for an occupant protection system that would better protect school bus passengers in all scenarios and then require new school buses to meet these standards.
In 2006, the NTSB placed this issue area on the Most Wanted List. On October 21, 2008, the National Highway Traffic Safety Administration (NHTSA) published a final rule implementing improvements to school bus passenger protection, including an increase to the minimum seat back height, mandatory installation of lap/shoulder belts on small school buses, and performance requirements for voluntarily installed seat belts on large school buses. However, these new standards did not address side-impact and rollover accidents, and failed to provide a uniform level of safety to all school bus occupants. By providing guidelines for, rather than mandating, seat belts for larger buses, the rule puts the onus of safety level choice on state and local jurisdictions, forcing them to choose between economic concerns and passenger safety.