With the high number of deaths occurring on our nation’s highways, vehicle safety is a top concern. Roof strength is a critical component to survival in a rollover accident, yet roof crush standards continue to insufficient to ensure adequate occupant protection in rollover events. Recent testing and data show that roof strength has a significant effect on whether occupants in a rollover will be severely injured or killed.
Roof Strength is Critical
The strength of a vehicle’s roof is critical element in providing occupant protection in a rollover crash. According to the Department of Transportation (DOT), rollover crashes are the “most dangerous collision type for light duty vehicles.” The DOT estimates that more than 26,000 people are seriously injured every year during rollovers, and in 7,640 of those cases, “at least one injury was due to roof contact, and roof intrusion was present in 93% of those cases.” Over half of those occupants were wearing their seatbelts, but when survival space is compromised, serious and often fatal head and spine injuries occur.
While severe compression of the head and neck may be the biggest concern for belted occupants during a rollover, roof crush can also have severe consequences for unbelted occupants who may come to be ejected when roof deformity compromises other elements of the vehicle structure, like the doors and window glass. Roughly half of the 26,000 people seriously injured or killed in rollovers each year were ejected.
Surprisingly, many safety advocates argue that rollovers should be survivable accidents. This is due to the fact that the force applied to occupants is less than in a typical crash, as the vehicle typically contacts the ground upon each rotation as the vehicle rolls, lessening the force with each turn. Advocacy group, Public Citizen, contends that the high rate of death and injuries during rollovers suggests that “rollovers are dangerous due to poor vehicle design.”
Maintaining the Survival Space and Structure of the Vehicle
When designing vehicles, safety engineers consider the room over the heads of vehicle occupants, often referred to as the “survival space,” as maintaining that space is a crucial safety factor in a rollover.
Although seemingly irrefutable that maintaining an occupant’s survival space by strengthening roofs would help protect occupants, auto manufacturers have argued that roof strength is not related to safety in rollovers. The Alliance of Automobile Manufacturers has stated that “there remains no definitive answer as to what effect roof strength has on injury risk in rollover crashes.” The Alliance advocates for preventing rollovers from occurring through the use of technology such as Electronic Stability Control (ESC). However, the data correlating roof strength and serious injuries or death continues to grow. Adrian Lund, president of the Insurance Institute for Highway Safety (IIHS), stated that while features to reduce rollovers are an important step, “until these crashes are reduced to zero, roof strength will remain an important aspect of occupant protection.
IIHS conducted a series of tests on eleven mid-sized SUV’s to determine the effect of roof crush in real-world crashes. The Institute’s tests concluded that injury risk decreased as roof strength increased. Researchers agree that the stronger the roof, the greater the survival rate in a rollover.
Strengthening our Roofs: Proposed Legislation
Concern over roof crush standards has risen as the number of catastrophic injuries and deaths caused by roof crush has become more publicized. The current roof crush standard, unchanged since its implementation in 1973, requires that vehicles be able to withstand 1.5 times the weight of the vehicle. Vehicles are tested by applying weight to an upright vehicle by a flat panel, called a “static crusher.”The new proposal by the National Highway Transportation Safety Administration (NHTSA) plans to increases the standard to require vehicles withstand 2.5 times their weight. Several safety advocates, however, argue that the standard should be even higher.
Such supporters include Stephen Oesche, Senior Vice President of the Independent Insurance Institute for Highway Safety and Joan Claybrook, President of the non-profit consumer advocacy group, Public Citizen. Claybrook advocates for adopting dynamic testing, which makes testing more like real-world crashes as opposed to the current static testing used. Auto manufacturers argue that dynamic testing is not repeatable, but Claybrook points to the Jordan Rollover System (JRS) which has been used by insurance companies for years, and “accurately tests strength within a few degrees of separation for each test.”
While many auto manufacturers continue to oppose increasing standards for roof strength, cars like the Volvo XC90 have been designed to take roof strength seriously. Advertisements for Volvo state that “the roof strength of the XC90 exceeds the legal requirements in the USA by more than 100 percent.”
Although recent publicity regarding the dangers of roof crush has led to proposed increases in roof strength standards, these changes likely will not have a major effect on reducing deaths and injuries in rollovers. Some experts are advocating for vehicles to withstand up to four times their weight, and requiring dynamic testing with dummies in vehicles to better plan for what happens in an actual rollover.
Until legislative changes force auto manufacturers to make roof design improvements, the U.S. court system will continue to see lawsuits filed. Cases will continue to generate multi-million dollar verdicts against the auto industry, and more importantly, lives will continue to be lost in these “survivable” accidents. Realistic testing and stricter roof crush standards will lead to lives saved on the road.
 Department of Transportation, Request for Comments by NHTSA and DOT on Federal Motor Vehicle Safety Standards; Roof Crush Resistance, 49 CFR Part 571.
 Id. (noting the high number of rollover injuries related to roof crush and roof contact).
 Department of Transportation, supra n. 1.
 The Public Should Walk Away from Rollover Crashes—Few Do, Public Citizen, Protecting Health, Safety, and Democracy, http://www.citizen.org/autosafety/rollover/crashwrth_/articles.cfm?ID=13212.
 Tom Incantalupo, Group Calls for Stronger SUV Roofs, Newsday.com (Mar. 12 2008).
 SUV Rollover Test, NBC.com (Mar. 12, 2008).
 Joseph S. Enoch, Senators Question Roof Strength Safety Rules, Consumeraffairs.com (June 4, 2008).
 Roof-Crush Standards Fall Short: Safety Official to Strengthen Standards for First Time Since 1970s, CBS News, http://www.cbsnews.com/stories/20040/05/27/eveningnews/main620044.shtml (May 27, 2004).
 Nader Slams Feds for Caving on Roof-Crush Standards, Wired, http://blog.wired.com/cars/ 2008/05/ralp-nader-pro.html (May 9, 2008).