1. Why is the issue of vehicle rollover so important to Consumers Union?
2. How many people die in rollover accidents each year?
3. How do rollover accidents compare to other road and highway accidents?
4. How frequently do cars and trucks rollover?
5. Are SUVs more involved in rollover than other vehicles?
6. Aren't there already rollover ratings on NHTSA's website?
7. What should an accurate rollover test ideally entail?
8. When will NHTSA be adding dynamic testing results to its rollover resistance rating system?
9. How will NHTSA combine scores the various tests? Will there be one overall score?
10. Doesn't CU already test and rate vehicles for their rollover propensity?

1. Why is the issue of vehicle rollover so important to Consumers Union?
CU believes the severity of rollover accidents, the rapid rise in popularity of SUVs, and the fact that SUVs generally have a significantly higher propensity to roll over than do sedans, underscore the need for an accurate rollover ratings system, accessible by consumers on how a vehicle performs in a rollover test procedure. (For the latest SUV and other light truck sales statistics, see the U.S. Department of Energy website, http://www.ott.doe.gov/facts/archives/fotw277supp.shtml, SUVs of all types - big and small, car- and truck-based - accounted for about 25 percent of the nearly 11.4 million new vehicles sold through August, slightly ahead of 2002's pace. That puts SUVs on track to top last year's 4 million unit record.)

2. How many people die in rollover accidents each year?
In 2002, 10,666 people were killed in rollover crashes, up 5% from 2001, according to the Federal National Highway Traffic Safety Administration (NHTSA). In 2001, 10,138 people died in rollover crashes, a figure that represented 32% of occupant fatalities for the year. Of those, 8,407 were killed in single vehicle rollover crashes. 78% of the people who died in single-vehicle rollover crashes were not using a seatbelt, and 64% were partially or completely ejected from the vehicle.

3. How do rollover accidents compare to other road and highway accidents?
Rollover stands out as a category of highway fatality because the number of rollovers has increased, while the total number of highway fatalities has remained stable over the past decade. According to NHTSA's National Center for Statistics and Analysis, from 1991 to 2001 the number of passenger vehicle occupants killed in all motor vehicle crashes increased 4%, while fatalities in rollover crashes increased 10%. In the same decade, passenger car occupant fatalities declined 15% while rollover fatalities in light trucks increased 43%.

4. How frequently do cars and trucks rollover?
Though rollovers are relatively rare events, they are particularly deadly when they do occur. Overall, rollover affects about three percent of passenger vehicles involved in crashes, but represents nearly 1/3 of all occupant fatalities each year. For example, in 2001, 10,138 people died in rollover crashes, which represents 32 percent of passenger vehicle occupant deaths for the year.

Sixty-one percent of all occupant fatalities in sport utility vehicles (SUVs) and 45% of pickup truck deaths were the result of a rollover crash. By contrast, 22% of passenger car fatalities in 2002 were the result of a rollover crash. The estimated risk of rollover differs depending on the type of vehicle. 10% of cars and 10% of vans in single vehicle crashes rolled over, compared to 18% of pickup trucks and 27% of SUVs.

5. Are SUVs more involved in rollover than other vehicles?
Yes. NHTSA announced in July 2003 that "fatalities in rollover crashes accounted for 82% of the total fatality increase in 2002. . . The number of persons killed in sport utility vehicles (SUVs) that rolled over rose 14%. 61% of all SUV fatalities involved rollover."

6. Aren't there already rollover ratings on NHTSA's website?
Yes, but we believe the measure NHTSA is using provides too coarse a measure of vehicle stability. Currently NHTSA provides rollover ratings on its website (http://www.nhtsa.dot.gov/cars/problems/Rollover/vehicle_ratings.htm) that are based on a vehicle's "Static Stability Factor," or SSF. SSF has been used as one method of evaluating rollover propensity. It is a calculation based on two aspects of the vehicle: center of gravity, height, and track width (T/2H, with H being the center of gravity height and T being the track width).

CU believes risk estimates based on SSF alone - and what appears currently as ratings on NHTSA's website - is too coarse a measurement to give an accurate picture of a vehicle's propensity to roll over. We favor adding the results of a dynamic rollover test program to the SSF score, along with ratings from dynamic emergency handling tests, because these treat the vehicle as a unit, measuring its performance as a whole. Such an approach includes many more variables than simply a formula relating track width and height. Dynamic tests also reflect the stability of the vehicle in real-world driving situations and take into account the vehicle’s suspension and tires, which SSF cannot.

7. What should an accurate rollover test ideally entail?
Due to the complex nature of a rollover incident, a method of rating the rollover resistance of a vehicle needs to consider the key factors involved. These include:

1. Dynamic maneuvers that will assess handling performance at limit conditions;
2. Emergency handling tests to evaluate the tire grip and ease of control.
3. The center of gravity height and track width, as basic parameters;

All these factors should be measured, and provided separately as well as weighted and compiled into an overall score that would allow consumers to make an informed judgment on the rollover resistance of the vehicles they consider for purchase. This multi-factor approach also provides a system of checks and balances to assess whether the overall handling characteristics of a vehicle have been compromised in an effort to enhance performance in any single test.

CU has been working to get NHTSA to develop dynamic tests for rollover propensity and to publish the results of those tests for consumers since 1996 (see Rollover Timeline above). We believe such evaluations must include a dynamic test that simulates recognizable driving maneuvers. CU’s belief in the importance of dynamic testing was confirmed by Congress in the Transportation Recall, Enhancement, Accountability, and Documentation Act (TREAD) (Section 12), which called upon NHTSA to develop a dynamic test for rollover that would be the basis for "developing meaningful consumer information." CU believes that consumer safety will be dramatically improved as consumers are able to access ratings based in large part on dynamic testing for a wide array of light trucks - SUVs, minivans and pickup trucks.

8. When will NHTSA be adding dynamic testing results to its rollover resistance rating system?
In direct response to the mandate in the TREAD (Transportation Recall Enhancement, Accountability, and Documentation Act) Act of 2000 to develop a dynamic test for rollover, NHTSA announced on October 7, 2003 that beginning with the 2004 model year, the agency would "enhance its current rollover ratings system with the addition of a dynamic track test." NHTSA decided that the dynamic test will use the so-called "fishhook maneuver," - a sequence involving two abrupt turns initiated at different speeds which CU believes is an effective maneuver to evaluate rollover resistance.

For more information on the enhanced rating system, see http://www.nhtsa.dot.gov/cars/rules/rulings/RollFinal/3rdTREAD-for-WebSite.pdf.

9. How will NHTSA combine scores the various tests? Will there be one overall score?
Starting with the 2004 model year, the rollover risk predictions will be based both on the vehicle's static stability factor and its performance in the dynamic test. Officials at NHTSA have said there will be one overall score. The format of the rollover rating system used now (one to five stars) will remain unchanged. One star is for rollover risk greater than 40%; five stars, 10% or less.

10. Doesn't CU already test and rate vehicles for their rollover propensity?
CU's dynamic tests evaluate a vehicle's "emergency handling" characteristics, not its rollover propensity per se. However, CU's tests provide a reliable basis for supporting our judgment that a vehicle that tips up severely during the CU avoidance maneuver tests exhibits dangerous behavior. Of the 120 vehicles put through the CU short course since 1988, three have tipped so severely as to have been judged Not Acceptable.