WASHINGTON -- Large passenger vans are more likely to have improperly inflated tires, making the vehicles even more susceptible to rollover accidents, U.S. regulators said on Thursday.
The National Highway Traffic Safety Administration said a new study found that 15-passenger vans are nearly twice as likely as passenger cars to have mis-inflated tires and it urged van drivers to check tire pressure frequently.
The 15-passenger vans at issue are made only by General Motors and Ford Motor Co.
The agency said improperly inflated tires can change vehicle handling characteristics, increasing the prospect of a rollover.
Data from the new research showed 74 percent of all 15- passenger vans had significantly mis-inflated tires, the agency said. By contrast, 39 percent of passenger cars were found with significant inflation problems.
Fifteen-passenger vans are popular with colleges, church groups and civic organizations.
Agency spokesman Mark Krawczyk said the mis-inflation was mainly a maintenance problem, noting that the large vans are often used and maintained by multiple drivers.
The government has issued a series of warnings about the rollover risk of 15-passenger vans. Previous research has indicated the large vans have a rollover risk that rises dramatically as the number of occupants increases to full capacity.
According to government statistics, there were 1,576 15-passenger vans involved in fatal crashes between 1990 and 2002. Of those, 349 were single vehicle rollover crashes. Most victims were not wearing safety belts.
The likelihood of rollover when a van is fully loaded is about five times greater than when the vehicle contains only a driver, the agency has said.
In June 2004, the agency issued the latest of several warnings about the rollover risk of the 15-passenger vans, based on new data that showed the chances of rollover increased significantly at speeds over 50 mph (80 kph) and on curved roads.
Similar warnings on rollover propensity were issued in 2001 and 2002.