If you've been following the ongoing roof strength regulation saga, this will likely come as no surprise. Transportation Secretary Mary Peters has again asked for an extension to rewrite the government's vehicle roof strength rule. We've been reporting on this for more than three years, and the delays never seem to end (of course, we can assume the big cheese in Washington have more pressing issues on their plates these days). Rewriting the legislation set back in the 1970s isn't as simple as specifying stronger roof pillars. Beefing up the roof will add weight – potentially making a vehicle more top heavy and likely increasing the possibility of a rollover. The new rules will need to address these concerns, and take into account new safety technologies (curtain airbags, stability control, etc...) that are on our current-generation models. While each previous request for an extension included new deadline dates, this latest appeal didn't. A wise move considering the administration's track record on this issue.
While rollover resistance is improving, current vehicle roof strength regulations date back nearly 35 years. With that in mind, Congress will be taking a careful look at federal regulators as they work on upgrading the standards early next month before they unveil a final regulation at the end of July. Current standards require a vehicle under 6,000 pounds to withstand a force of 1.5 times the vehicle weight without crushing and striking the head of a belted average-size adult male. In August 2005, the National Highway Traffic Safety Administration (NHTSA) proposed toughening that standard to 2.5 times the vehicle weight (and adding it should cover all vehicles under 10,000 pounds). Safety advocates, however, have argued that the standard should be 3 to 3.5 times the vehicle weight.
According to the NHTSA, increasing the crush resistance to 3 times the vehicle weight would cost automakers at least $1.1 billion more that it would to meet the 2.5 standard. Automakers have shown resistance to the proposals too. They have asked for more time to comply with the toughened rules, and that some vehicles (such as the Jeep Wrangler) be exempt. They have also pointed out that increased roof strength means added weight -- counterproductive in their continued efforts to meet stringent fuel economy standards.
Crash safety ratings are a big selling point – who's going to buy a car with just two stars? In pursuit of salable collision performance, automakers have turned to stronger metals and better construction, and consumers can reap the benefit by choosing from a panoply of highly rated vehicles. A problem arises, however, if that safety design is ever called upon to perform. Lots of vehicles now sport high strength steel in critical areas like roof pillars, and while it certainly helps protect occupants, it could hinder rescue crews. Tools that once made quick work of crashed vehicles are now having trouble shearing through modern cars. Not only that, modern cars have lots of airbags around the cabin, and there are also worries about cutting high-voltage electrical cabling in hybrid or electric vehicles. Rescuers need to know where all the potentially hazardous equipment lies within a vehicle so that they can safely retrieve human cargo without creating a further tragedy.
What was once a simple matter of cutting a roof off to get passengers out can now become a sawblade-eating saga that takes double or triple the time. Taking more time at an accident scene has repercussions that put recovery or even survival at risk by delaying treatment. Automakers are aware of this, and they're working with public safety entities to provide training and information. Schematics and build details of vehicles are being made available to first responders by the non-profit group COMCARE Emergency Response Alliance. The ability to research where and how a car should be taken apart in an emergency could buy injured people critical minutes, so Ford, for instance, is asking for a dialogue with rescue crews and the makers of their tools by offering a look at the construction of the 2009 F-150. Upgrades to rescue tools are also necessary, but the flip side of the harder rescue is that the death rate from passenger car accidents is historically low. So buy that five-star vehicle and try not to hit anything.
There's been considerable debate between automakers, legislators and safety advocates over how roof strength correlates to deaths in rollover crashes. The majority of the focus has appropriately been heaped on SUVs, whose high center of gravity makes them more prone to rollovers, particularly when they leave the road.
The Insurance Institute for Highway Safety has just released a study that proves that more roof strength can reduce injuries by some 39 to 57 percent when compared to the weaker models it tested. The IIHS used the same roof strength test as the feds on a group of SUVs that currently meet the government's roof requirements. At the top of the heap was the 2000-2004 Nissan Xterra that was able to withstand almost 12,000 pounds of force, while the lowest ranked vehicle, the 1999-2004 Jeep Grand Cherokee, lost its head(room) after 6,500 pounds of force was applied to the roof.
Vehicle roof crush standards have not been significantly revised since 1971. The current requirements say one side of a vehicle's roof must support at least 1.5 times the total vehicle weight. However, the strength requirements reach a maximum at 5,000 lbs, whether or not the calculated standard is greater. The regulations also do not apply to convertibles or vehicles weighing more than 6,000 lbs. In 2005, a proposal was created to revise the requirement to 2.5 times the total vehicle weight on one side of the vehicle. Now that proposal has been altered, since NHTSA says it is feasible to distribute the test to press on both sides of a vehicle's roof. It has also been proposed to increase the standards to cover vehicles up to 10,000 lbs. An active rollover test is ruled out though, due to repeatability issues and lack of variable control. To appease Congress, NHTSA must put a revised standard in place by April 2009.
While updating safety standards is always a good thing, the issued statements relating to the proposal leave some questions. It is not stated whether the testing weight cap of 5,000 lbs will be increased along with the maximum tested vehicle weight. These days, many automobiles weigh in at upwards of 4,000 lbs. 2.5 times a 4,000-lb vehicle falls well above the 5,000-pound limit. There is also still no mention of convertible safety. Hopefully the full proposal is more detailed than the points touched upon in this piece.
