Ejection rule could change side airbags
`
`IIHS and HLDI
`
` logos
`
`RATINGS
`
`NEWS
`
`TOPICS
`
`VIDEO
`
`STATUS REPORT
`
`Highway safety research
`& communications
`
`Home » Status Report » 2011 » Article
`
`Status Report, Vol. 46, No. 4 | April 26, 2011
`
`Subscribe
`
`New ejection rule may spur changes in side airbags
`
`More on rollover crashes
`
`More on airbags
`
`Side curtain airbags that deploy in rollovers as well as side impacts are expected to become
`the norm, thanks to a new federal standard aimed at decreasing ejections from passenger
`vehicles. The rule, issued in January by the National Highway Traffic Safety Administration
`(NHTSA), also provides an incentive for manufacturers to use laminated glass on side
`windows, something the Institute backs.
`
`While supporting the goals of the regulation, Institute researchers point out that it requires
`some changes to current airbags that aren't proven to be needed. It's unclear how those
`changes will affect crash protection.
`
`"Research shows that side curtain airbags are very effective at reducing injury risk in side
`crashes," notes Matthew Brumbelow, a senior research engineer for the Institute. "We hope
`the changes required by the new regulation don't diminish this."
`
`Rollovers make up about 3 percent of all crashes but more than a third of passenger vehicle
`occupant deaths. Nearly half the people killed in rollovers are thrown from vehicles. NHTSA
`has estimated that occupants who are fully ejected are 56 percent more likely to die than those
`who remain in a vehicle during a rollover. Most ejected people go through side windows, and
`the vast majority are unbelted.
`
`Side airbags that deploy in a rollover can play a key role in keeping occupants inside the
`vehicle. They deploy from the roof downward in response to sensors that measure a vehicle's
`sideways movement and tilt.
`
`Most new vehicles come with side airbags to protect the head and torso, and the equipment is
`on its way to becoming universal because of new standards for side protection. Manufacturers
`now are expected to modify side airbags in response to the new ejection rule. In addition to
`deploying in a rollover, the airbags will need to cover more of the side windows and stay
`inflated longer than airbags designed solely for side impacts.
`
`Airbags in some vehicles already do all that, but most of them still will have to be changed to
`meet the standard. That's because NHTSA is requiring systems that prevent the equivalent of
`an unbelted adult's head from moving more than 4 inches past the side window opening. Most
`current side airbags allow more movement than that, and it's unclear that such a strict standard
`is necessary.
`
`http://www.iihs.org/iihs/sr/statusreport/article/46/4/4[5/6/2017 9:55:21 PM]
`
`Side airbag coverage gaps that could result in occupant
`ejection were revealed in NHTSA tests like this one.
`
`IPR 2016-01790
`American Vehicular Sciences
`Exhibit 2034
`
`

`

`Ejection rule could change side airbags
`
`The 4-inch rule is intended to prevent a situation in which an airbag gets pushed outside the
`vehicle so far that the bottom of it falls out, creating a gap through which a person could be
`ejected. NHTSA says the 4-inch rule is used in standards concerning certain aspects of
`vehicle doors and bus windows and in international building codes for stair and balcony railings.
`But those standards all have to do with the width of openings, while in the new regulation the
`4-inch limit refers to how far the test device can move outside the window as it pushes on the
`airbag, not to the size of a resulting opening.
`
`Of the 24 vehicles with rollover airbags NHTSA tested ahead of the rule, only 1 met the
`requirement. The others will need changes, probably stiffer airbags that inflate more powerfully.
`The effects of these changes in other crashes are unknown, but it's possible that stiffer airbags
`could be less effective at preventing head or neck injuries in some cases. Added force when
`an airbag deploys also could cause injuries. Up to this point, injuries from side airbag
`deployments have been rare, in part because of voluntary guidelines manufacturers adopted to
`minimize inflation injuries (see "Consumers get new information on side airbags with reduced
`injury risk," Sept. 13, 2004).
`
`In announcing its decision, NHTSA cited 6 real-world cases in which rollover airbags didn't
`prevent ejection. In none of the cases was there evidence an occupant pushed past a too-
`weak airbag — the issue the 4-inch rule is meant to address. Instead, the airbags may have
`had deployment problems or simply didn't cover enough of the window.
`
`"Although there have been some ejections from vehicles with rollover airbags, there's no
`compelling evidence that the 4-inch rule will fix that," Brumbelow says. The Institute expressed
`reservations about the 4-inch limit in a comment to NHTSA last year.
`
`The Institute got a more favorable response to its suggestion that NHTSA encourage the use
`of shatter-proof laminated glass for side windows as a complement to side airbags. The rule
`allows side windows to remain rolled up for 1 of 2 required tests. That way, the window can
`help keep side airbags in place during the test, providing an incentive for stronger glass.
`
`The standard will be phased in beginning in 2013, with all new vehicles required to meet it by
`the 2018 model year. NHTSA estimates that when fully implemented, the requirement will
`prevent 373 deaths and 476 serious injuries every year. Institute researchers believe those
`estimates are high because NHTSA undercounts the benefit of a more stringent roof strength
`standard to be phased in by 2017. Institute studies have shown that stronger roofs reduce the
`risk of occupant ejection (see Status Report special issue: roof strength, March 24, 2009).
`
`Also in this issue
`First crash tests of electric cars
`
`Hours-of-service proposal still has flaws
`
`Proposal calls for truck onboard recorders
`
`ACCESS MORE ISSUES
`
`Media contact
`Russ Rader
`Senior Vice President, Communications
`rrader@iihs.org
`office +1 703 247 1530
`mobile +1 202 257 3591
`
`For more information, visit our press room.
`
`Press room
`Broadcast-standard
`video and info for
`the media
`
`About us
`Contact us
`FAQ
`
`Our Vehicle
`Research Center
`
`Recent IIHS & HLDI
`presentations
`
`Member groups
`& funding associations
`
`Consumer safety
`brochures
`
`Help page
`
`Privacy policy
`
`Vehicle testing &
`highway safety links
`
`Subscribe to news updates
`
`Watch our channel
`
`Follow us
`
`Mobile ratings & news
`
`©1996-2017, Insurance Institute for Highway Safety, Highway Loss Data Institute, 501(c)(3) organizations | Copyright information
`
`http://www.iihs.org/iihs/sr/statusreport/article/46/4/4[5/6/2017 9:55:21 PM]
`
`

`

`Ejection rule could change side airbags
`
`http://www.iihs.org/iihs/sr/statusreport/article/46/4/4[5/6/2017 9:55:21 PM]
`
`