
The National Highway Traffic Safety Administration (NHTSA) has announced a new rule to help decrease passenger ejections in vehicle rollovers. Under the rule, vehicle manufacturers must develop a solution to prevent an unbelted adult from moving more than four inches past the side window in a crash situation. This new vehicle standard would be in place starting in 2013 with a requirement by all vehicles under 10,000 lbs. to have this protection by the 2018 model year.
Rollover accidents killed over 8,200 people in 2009. From 2000-2009, 47 percent of people killed in rollover accidents were completely ejected from the vehicle and many of those killed were not wearing seat belts. NHTSA believes the standard will prevent around 373 fatalities and 476 serious injuries each year.
This is the final step in an initiative to improve the safety of vehicle occupants. The first measures included the mandate for electronic stability control to be in all vehicles for the 2012 model year and a new pole test by NHTSA that requires manufacturers to install new technologies to improve head and thorax protection in side crashes. This is being addressed largely with side-curtain airbags and torso airbags. This final rule effectively leads to the side-curtain airbags being larger and remaining inflated longer.
Since 2001, NHTSA has assigned rollover resistance ratings to vehicles and last October they updated the star safety system, which includes a more comprehensive evaluation of front crashes, side crashes, and rollover resistance. A number of 2011 models have been evaluated under these new ratings with more to come.
NHTSA currently conducts roof-crush tests by pressing down on a plate placed against the edge of a vehicle’s roof. The roof has to withstand a force equivalent to 1.5 times the weight of the vehicle, up to a limit of 5,000 pounds, without the plate moving more than five inches.
A revised regulation enacted in 2009 requires vehicle roofs to withstand three times the vehicle’s weight in that test. Under that force, the roof should not bend so far that it would touch the head of a median-height-male test dummy. How far the roof could crush without touching the head of the dummy would depend on the dimensions of the vehicle. It also requires, for the first time, that vehicles over 6,000 pounds meet a roof-crush standard, although the standard for the heaviest passenger vehicles will remain at 1.5 times the vehicle’s weight. The revised roof-crush standard starts phasing with the 2012 model year and applies to all new vehicles by the 2017 model year.
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