Federal Motor Vehicle Safety Standards; Bus Emergency Exits and Window Retention and Release, Anti-Ejection Glazing for Bus Portals

摘要

This NPRM proposes a new Federal Motor Vehicle Safety Standard (FMVSS) No. 217a, "Anti-ejection glazing for bus portals," to drive the installation of advanced glazing in high-occupancy buses (generally, over-the-road buses (of any weight) and non-over-the-road buses with a gross vehicle weight rating greater than 11,793 kilograms (26,000 pounds). The new standard would specify impactor testing of glazing material. In the tests, a 26 kilogram (57 pound) impactor would be propelled from inside a test vehicle toward the window glazing at 21.6 kilometers/hour (13.4 miles per hour). The impactor and impact speed would simulate the loading from an average size unrestrained adult male impacting a window on the opposite side of a large bus in a rollover. Performance requirements would apply to side and rear windows, and to glass panels and windows on the roof to mitigate partial and complete ejection of passengers from these windows and to ensure that emergency exits remain operable after a rollover crash. NHTSA also proposes to limit the protrusions of emergency exit latches into emergency exit openings of windows to ensure they do not unduly hinder emergency egress. This NPRM is among t