The National Highway Traffic Safety Administration (NHTSA) Issued a Final Rule Creating FMVSS 227 – Bus Rollover Structural Integrity
The National Highway Traffic Safety Administration (NHTSA) established Federal Motor Vehicle Safety Standard FMVSS) No. 227 - Bus Rollover Structural Integrity when it issued a Final Rule (FR) in the December 29, 2021 Federal Register (F.R. Vol. 86 No. 247; NHTSA-2021-0088). This action is intended to enhance the rollover structural integrity of over-the-road buses (motorcoaches) and other buses with GVWR greater than 26,000lb. This action follows the direction provided in Moving Ahead for Progress in the 21st Century Act (MAP-21). The intent of these actions is to provide "survival space" in a rollover test to protect occupants from possible collapse of the bus structure. Additionally, it is to reduce the likelihood of ejection and prohibit emergency exits from opening in the rollover test.
NHTSA has long identified four priority areas for motorcoach and other large bus safety improvements which this FR addresses: passenger seat belts, improved rollover structural integrity, improved emergency evacuation, and fire safety. NHTSA has completed research and rulemaking on the first two priority areas and completed research on the other two.
An over-the-road bus (OTRB) is a bus characterised by an elevated passenger deck located over a baggage compartment. NHTSA has used the term OTRB in the FMVSSs issued pursuant to the MAP-21 mandates. For example, NHTSA fulfilled MAP-21's seat belt mandate by amending FMVSS 208 - Occupant Crash Protection, to require seat belts in each passenger seating position in OTRBs, as well as some non-OTRBs with a GVWR greater than 26,000lb. NHTSA uses the term "large buses" in this FR to refer to OTRBs regardless of GVWR and non-OTRBs with a GVWR greater than 26,000lb, with some exceptions.
This FR establishing FMVSS 227, will ensure that all new large buses required to have lap and shoulder seat belts for passengers since 2016, will be significantly protected against unreasonable risk of injury in frontal crashes and against the risk of ejection in rollovers. Along with the seat belt rule, this FR enhances the safety of these belted passengers by providing a "survival space" in a rollover, a space where the belted occupants are protected from intruding structures such as a collapsing roof or a detached luggage rack. The FR's improvements to the roof and sidewall strength of the buses will also protect unbelted occupants against structural failure of the bus compartment.
This FR improves transportation safety for the most vulnerable in our society since more than half of motorcoach trips are made by children and senior citizens. Additional transportation equity is provided by giving the same occupant crash protection as that provided to occupants of other passenger motor vehicles by reducing deaths and injuries due to the crushing of the roof into the occupant compartment in rollover crashes. This FR applies to all new large buses, with limited exceptions. The FMVSS does not apply to school buses, prison buses, buses with perimeter seating, or to transit buses that are not OTRBs. School buses already meet FMVSS 220 for roof strength and rollover protection. In response to comments, NHTSA has also decided not to apply the standard to "school bus derivative buses," which this FR defines as buses built on a school bus platform. seating and passenger protection," but the buses have safety systems that are otherwise identical to school buses regarding their emergency exits, rollover protection, bus body joint strength, and fuel system integrity. The vehicles could be certified as meeting the FMVSSs for "school buses" if they had school bus lights meeting FMVSS No. 108, stop arms meeting FMVSS No. 131, and seating systems meeting FMVSS No. 222.
The test for the large buses adopted by this FR is the complete vehicle rollover test of United Nations Economic Commission for Europe (ECE) Regulation 66 - Uniform Technical Prescriptions Concerning the Approval for Large Passenger Vehicles with Regard to the Strength of their Superstructure, (ECE R.66).
This FR mainly follows the Notice of Proposed Rulemaking (NPRM) issued August 6, 2014 (79 FR 46090) by:
- This FR adopts the NPRM's proposed ECE R.66 full vehicle test to improve the roof and structural integrity of OTRBs and non-OTRBs with a GVWR greater than 26,000lb, except for a few buses with unique configurations.
- This FR adopts the NPRM's proposed prohibition that no part of the bus that is outside the survival space shall intrude into the survival space, both during movement of the tilting platform or resulting from impact of the bus on the impact surface; however, the FR permits debris weighing not more than 15.0g.
- This FR does not adopt the NPRM's proposal that each anchorage of an interior overhead luggage rack or other compartment must not completely separate from its mounting structure during movement of the tilting platform or resulting from impact of the bus on the impact surface. It also does not adopt the NPRM's proposal that seat anchorages must not become dislodged during the test. Under the NPRM, those proposed prohibitions would have applied even if the luggage rack does not enter the survival space, or the seat anchorages dislodged within the survival space.
- This FR does not adopt the proposed provision that each side window glazing opposite the impacted side of the vehicle must remain attached to its mounting structure so as not to allow the passage of a 102mm (5in) diameter sphere.
The Final Rule is effective December 30, 2024. Petitions for Reconsideration are to be submitted by February 14, 2022.
The Final Rule is available on InterRegs.NET for our US Federal subscribers and is also available at www.selectregs.com.