Most consumers who are shopping for a new car depend on good
crash safety ratings as an indicator of how well the car will perform in a
crash. But a new University at Buffalo
study of crashes involving cars and sport utility vehicles (SUVs) has found
those crash ratings are a lot less relevant than vehicle type.
10 times the risk
In head-on collisions between passenger cars and SUVs, the
UB researchers found that drivers in passenger cars were nearly 10 times more
likely to die if the SUV involved had a better crash rating. Drivers of
passenger cars were more than four times more likely to die even if the
passenger car had a better crash rating than the SUV.
“When two vehicles
are involved in a crash, the overwhelming majority of fatalities occur in the
smaller and lighter of the two vehicles,” says Dietrich Jehle, MD, UB professor
of emergency medicine at Erie County Medical Center and first author.
“But even when the two vehicles are of similar weights,
outcomes are still better in the SUVs,” he says, “because in frontal crashes,
SUVs tend to ride over shorter passenger vehicles, due to bumper mismatch,
crushing the occupant of the passenger car.”
Odds of dying
When crash ratings were not considered, the odds of death
for drivers in passenger cars were more than seven times higher than SUV
drivers in all head-on crashes. In crashes involving two passenger cars, a
lower car safety rating was associated with a 1.28 times higher risk of death
for the driver and a driver was 1.22 times more likely to die in a head-on
crash for each point lower in the crash rating.
The UB researchers conducted the retrospective study on
severe head-on motor vehicle crashes in the Fatality Analysis Reporting System
(FARS) database between 1995 and 2010. The database includes all motor vehicle
crashes that resulted in a death within 30 days and includes 83,521 vehicles
involved in head-on crashes.
“Along with price and fuel efficiency, car safety ratings
are one of the things that consumers rely on when shopping for an automobile,”
says Jehle. These ratings, from one to five stars, are based on data from
frontal, side barrier and side pole crashes that compare vehicles of similar
type, size and weight. The one to five star safety rating system was created in
1978 by the National Highway Traffic Safety Administration.
Jehle notes that after manufacturers addressed the roll-over
problem with SUVs that plagued these vehicles in the 1980s and 1990s, rollover
crashes are now much less common in SUVs.
“Currently, the larger SUVs are some of the safest cars on
the roadways with fewer rollovers and outstanding outcomes in frontal crashes
with passenger vehicles,” he says.
Jehle says that prior studies on frontal crashes have found
that compared to passenger cars with a 5-star crash rating, cars with a rating
from one to four stars have a 7-36% increase in driver death rates.
“Passenger vehicles with excellent safety ratings may
provide a false degree of confidence to the buyer regarding the relative safety
of these vehicles as demonstrated by our findings,” says Jehle. “Consumers
should take into consideration the increased safety of SUVs in head-on crashes
with passenger vehicles when purchasing a car.”
Co-authors with Jehle, all from UB, are: Albert Arslan and
Chirag Doshi, MD candidates in the School of Medicine and Biomedical
Sciences; Joseph Consiglio, data
manager/statistician for the UB Department of Emergency Medicine and a graduate
student in the Department of Biostatistics in the School of Public Health and
Health Professions; Juliana Wilson DO, a post-doctoral scholar in the
Department of Emergency Medicine and Christine DeSanno DO, a resident in the UB
Department of Emergency Medicine.