The National Highway Traffic Safety Administration published three proposed changes to the October 2008 final rule on seat belts in school buses centering on how the height of occupant torso belts are measured, integrated seat belts for wheelchairs and the self-latching requirement for seat cushions.
The clarification was posted on the Federal Register on Oct. 29 for Docket No. NHTSA-2008-0613. The clarifications are set to go into effect on April 27, 2011. Petitions for reconsideration of the final rule must be received not later than Dec. 13, 2010. NHTSA noted that it denied all other requests for reconsideration.
The definition of “school bus torso belt adjusted height” was clarified by adding a new Figure 5 in FMVSS No. 210 “to set forth in a clearer, more detailed manner how the torso belt adjusted height measurement will be made.” NHTSA seeks to remove what it called “the confusing phrase that deviates more than 10 degrees from the horizontal plane and adds a new figure to indicate that the measurement is made to a horizontal segment of the torso belt that is located between 25 mm to 75 mm (1 in to 3 in) forward of the adjustment device while applying a horizontal 20 N (4.5 lb) force to the belt in the forward direction. The 20 N (4.5 lb) horizontal force is applied in the forward direction through the webbing at a location greater than 100 mm (3.94 in) forward of the adjustment device (as shown in the new Figure 5) after the retractor has been locked. Figure 5 also illustrates that slack should remain in the portion of the belt between its bottom anchorage and the point of force application. This slack allows the upper portion of the torso belt, between the point of force application and the adjuster, to be pulled in a horizontal plane.”
NHTSA clarified that the requirement that seat belts be integral to the passenger seat, “…adopted to reduce the likelihood of passengers getting injured by or tangled in loose belts,” also applies to seats that have wheelchair positions or side emergency doors behind them, “even if the seats are in the last row of vehicles.”
NHTSA also seeks to “slightly” revise the procedure for how self-latching seat cushions based on the weight exerted on the seat cushion in measurements of Newtons “to specify that the downward force is applied in a one to five second timeframe [sic], and to specify that activation of the self-latching mechanism is assessed using the seat cushion retention test.” Those provisions are sought to make the language more consistent with that of a pre-existing seat cushion retention test in the standard.
The clarifications resulted from petitions for reconsideration filed by school bus manufacturers Blue Bird and IC Bus as well as seat manufacturers C.E. White and M2K, and the Marietta City School District in Ohio.
According to the Federal Register posting, the companies and school district asked NHTSA to reconsider: “The stringency of the FMVSS No. 210 requirements adopted for large school buses (IC believed the requirements were unnecessarily high); the application of FMVSS No. 207 to small school bus seats with lap/shoulder belts (Blue Bird believed the standard need not apply to the vehicles); the requirement for seat width (M2K believed all seats should be allowed to be a minimum of 257 mm (10.1 in) wide; the specifications in the final rule for measuring the school bus torso belt adjusted height (Blue Bird requested further clarification); the types of seats which must have integral seat belts (Blue Bird suggested that the requirement should apply to seats that have wheelchair positions or side emergency doors behind them); and, the test requirements for self-latching seat cushions (Blue Bird, M2K, MCSD).
Messages left with industry insiders, such as the petitioning companies as well as NAPT had not yet been returned. NSTA President Donnie Fowler said he was positive the issue would be discussed during a committee meeting on Monday.
No immediate take on the clarifications were available from NASDPTS representatives, but that will likely soon change. Charlie Hott, a NHTSA safety standards engineer who played a large role in the final rule, was scheduled to present at the annual NASDPTS meeting on Saturday. But conference chair and NASPDTS President-Elect Mike Simmons confirmed that Hott would no longer be speaking to state directors and other interested parties. Instead, John Moffatt, NHTSA’s regional administrator for the Northwest, will take Hott’s place in the agenda.