Washington The government warned on Monday that 15-passenger vans like those used to shuttle college teams, church groups and airport passengers have a dramatically higher risk of rollover when fully loaded.
The National Highway Traffic Safety Administration also said the vans, often driven by students or volunteers, should be operated only by experienced drivers.
NHTSA issued the rare consumer advisory after finding the vans are three times more likely to roll over when carrying 10 or more passengers. The study was prompted by a series of rollovers involving college sports teams.
Four members of the Prairie View A&M University track team were killed and seven others were seriously injured when their van rolled over on the way to a meet last year. Other serious rollover accidents last year involved the Wisconsin-Oshkosh swim team, the DePaul women's track team and the Kenyon College swim team.
NHTSA found that when fully loaded, a large van's center of gravity shifts up and to the back, increasing the risk of rollovers, especially in panic maneuvers by drivers.
"You have a vehicle that behaves entirely differently than when they are lightly loaded," NHTSA spokesman Rae Tyson said. "There is nothing inherently wrong with these vehicles as long as you understand those characteristics and take that in to account."
Officials from General Motors Corp., Ford Motor Co. and DaimlerChrysler AG agreed that van drivers need to be especially cautious. Ford, which makes the top-selling Econoline, warns drivers in its owner's manual to avoid sharp turns, excessive speed and abrupt maneuvers, but the other two manufacturers do not.
NHTSA officials said there are about 1.4 million 15-passenger vans registered in the United States. The agency identified a number of 15-passenger models, although its list may not include all models: Econoline E350, Chevrolet Express 3500, GMC Savana G3500, GMC Rally/Vandura G3500 and Dodge Ram Van/Wagon B3500.
Milton Chace, an Ann Arbor, Mich., engineer who has researched the rollover risk for plaintiffs' attorneys in several lawsuits, said at least half the lawsuits involve rented vans.
"You have a bad combination of an inexperienced driver who is going to fill it with close to 15 people and luggage," Chace said.
Anyone carrying 16 or more people for commercial purposes is required to have a commercial driver's license, but no special license or experience is required for the 15-passenger vans. Federal law bans the purchase of 15-passenger vans for schools, but there is no such ban for colleges.
In its study, NHTSA examined van crash data from seven states from 1994 through 1997. It found that 12.7 percent of the single-vehicle crashes with fewer than 10 occupants were rollovers, compared with 35.4 percent of accidents with 10 or more people. When 16 or more people were in the van, the number jumped to 70 percent.
Chace said rollover risk can be reduced if owners buy high-quality rear tires, keep the gas tank as full as possible and drive conservatively. He said passengers should fill front seats first and nothing should ever be loaded on the roof.