National Transportation Safety Board (NTSB) Chair Jennifer Homendy praised NHTSA's final rule aimed at  protecting occupants during motorcoach and large bus rollovers but said more needs to be done to provide the same level of safety for lighter-weight buses.

“NHTSA's action is a positive step toward ensuring occupant safety on motorcoaches and other large buses," said Chair Jennifer Homendy. “The NTSB has been calling for this protection for bus passengers for more than 20 years. Although more work is needed to protect occupants of all buses, we are encouraged by NHTSA's actions on this rulemaking and look forward to future rulemaking addressing lighter-weight buses."

On Dec. 29, NHTSA published its final rule creating Federal Motor Vehicle Safety Standard 227, “Bus rollover structural integrity," to enhance the structural integrity of motorcoaches and other buses with a gross vehicle weight rating greater than 26,000 pounds. The rule complements NHTSA's previous work requiring passenger lap/shoulder belts on these same bus types at all seating positions, increasing the protection of passengers during rollover crashes.

The NTSB updated its recommendations addressing bus roof strength and window integrity that originated in 1999, as a result of its investigation of the Sept. 20, 2019, crash in Bryce Canyon City, Utah.

The NTSB recommended that NHTSA require all newly manufactured buses, other than school buses, with gross vehicle weight ratings above 10,000 pounds to meet a roof strength standard that provides maximum survival space for all seating positions and accounts for typical window dimensions [Safety Recommendation H-21-02] and that NHTSA require all newly manufactured buses, other than school buses, with gross vehicle weight ratings above 10,000 pounds to meet a window glazing standard that prevents occupant ejection [Safety Recommendation H-21-03]. Note that school bus structures must currently meet Federal Motor Vehicle Safety Standard 220 “School bus rollover protection.'' Details about this safety issue and related recommendations are available on ntsb.gov.

Although the final rule represents progress in improving the safety of bus passengers, the rule does not address buses between 10,000 and 26,000 pounds. The NTSB has investigated multiple fatal bus crashes, involving buses in this size range where roof integrity was insufficient to protect passengers. ​