Flaws in the design and performance of safety belts leave vehicle occupants vulnerable to serious and often-fatal injuries in rollover crashes, says a report by Public Citizen, a consumer advocacy group.

“Safety belts are currently the most important safety feature that would keep people secure and inside the vehicle during a rollover crash,” said Public Citizen President Joan Claybrook. “It is inexcusable to install belts that do not do the job. The auto industry has known for decades how to design belts to better protect occupants in rollover crashes but has failed to do so.”

As SUVs proliferate on U.S. roads, fatalities in rollover crashes have climbed to one-third of all vehicle occupant fatalities, or 10,600 each year, the report says. The three risks of rollover - roof crush, ejection from the vehicle and belt failure - combine to make rollover crashes unnecessarily deadly. All three of the risks compromise or destroy occupants’ survival space during a crash and are inter-related. The report says roof crush becomes more deadly as seat belt use increases.

The auto industry continues to blame drivers and passengers for failing to use safety belts, but belt use is at an historic high and rollover fatalities are not abating, Public Citizen said in a statement issued on Monday.

Statistics show that while safety belts usually keep occupants from being completely ejected from a vehicle during a rollover, they often allow partial ejection, which is deadly. Moreover, six of 10 occupants who suffer serious or fatal injuries in rollovers inside the vehicle were wearing a safety belt, according to the National Highway Traffic Safety Administration.

The report, Rolling Over on Safety: The Hidden Failures of Belts in Rollover Crashes, also pointed out a discrepancy between observed belt use and rollover fatalities. Average belt use by SUV occupants is slightly higher than passenger car occupants, but recorded belt use by SUV occupants killed in rollovers is much lower than passenger car occupants killed in rollovers. The discrepancy suggests that some SUV occupants may come out of belts during the crash, or the belts may otherwise fail.

Public Citizen is calling Congress to enact vehicle safety measures in S.1072, a comprehensive approach to making rollover crashes survivable.

(via Public Citizen)