"Compared with the current federal standard of 1.5, a strength-to-weight ratio of 4 reflects an estimated 50 percent reduction in the risk of serious or fatal injury in single-vehicle rollover crashes," Lund explains.
The Smart withstood a force of 5.4 times its weight. The Aveo withstood a force of just over 3 times its weight.
Cars have been built to meet the same roof crush standard, Federal Motor Vehicle Safety Standard 216, since 1973. The rule was extended in 1994 to include all passenger vehicles up to a gross weight rating of 6,000 pounds. Many SUVs and pickup trucks are heavier, so they're exempt.
New federal requirements: In April the National Highway Traffic Safety Administration ended numerous delays by unveiling a new rule that doubles the current roof strength requirement (strength-to-weight ratio of 1.5) for vehicles with weight ratings up to 6,000 pounds. Roofs on vehicles with weight ratings 6,000 to 10,000 pounds will be required to withstand a force equal to 1.5 times their unloaded weight. Another requirement is that roofs maintain sufficient headroom during testing. For the first time, the government also will require the same performance on both sides of the roof when tested sequentially. Phase-in begins in September 2012, and all vehicles must comply by September 2016.
"The federal government's leisurely phase-in of the new standard means roofs won't have to get stronger right away," Lund says, "so we plan to continue rating vehicle roof strength for the foreseeable future. We want to reward manufacturers who are ahead of their competition when it comes to providing protection in rollover crashes. We want to help consumers identify the safest vehicle choices."
Roof ratings added to award criteria: A good roof strength rating will be a new requirement to earn the Institute's Top Safety Pick award for 2010. This is the second time criteria for this award have been tightened since the first winners were announced in 2005. Availability of electronic stability control became a requirement starting with 2007s.
"Adding roof strength to Top Safety Pick criteria means we're going to see fewer winners in 2010," Lund points out. A record 84 vehicles have qualified for the 2009 award so far.
photo:IIHS
The Smart withstood a force of 5.4 times its weight. The Aveo withstood a force of just over 3 times its weight.
Cars have been built to meet the same roof crush standard, Federal Motor Vehicle Safety Standard 216, since 1973. The rule was extended in 1994 to include all passenger vehicles up to a gross weight rating of 6,000 pounds. Many SUVs and pickup trucks are heavier, so they're exempt.
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New federal requirements: In April the National Highway Traffic Safety Administration ended numerous delays by unveiling a new rule that doubles the current roof strength requirement (strength-to-weight ratio of 1.5) for vehicles with weight ratings up to 6,000 pounds. Roofs on vehicles with weight ratings 6,000 to 10,000 pounds will be required to withstand a force equal to 1.5 times their unloaded weight. Another requirement is that roofs maintain sufficient headroom during testing. For the first time, the government also will require the same performance on both sides of the roof when tested sequentially. Phase-in begins in September 2012, and all vehicles must comply by September 2016.
"The federal government's leisurely phase-in of the new standard means roofs won't have to get stronger right away," Lund says, "so we plan to continue rating vehicle roof strength for the foreseeable future. We want to reward manufacturers who are ahead of their competition when it comes to providing protection in rollover crashes. We want to help consumers identify the safest vehicle choices."
Roof ratings added to award criteria: A good roof strength rating will be a new requirement to earn the Institute's Top Safety Pick award for 2010. This is the second time criteria for this award have been tightened since the first winners were announced in 2005. Availability of electronic stability control became a requirement starting with 2007s.
"Adding roof strength to Top Safety Pick criteria means we're going to see fewer winners in 2010," Lund points out. A record 84 vehicles have qualified for the 2009 award so far.
photo:IIHS