The US Department of Transportation's National Highway Traffic Safety Administration (NHTSA), has reissued a cautionary warning to users of 15-passenger vans because of an increased rollover risk under certain conditions. A similar warning was issued in 2001.

The safety agency also unveiled a consumer flyer for users of 15-passenger vans.

NHTSA research has shown that 15-passenger vans have a rollover risk that increases dramatically as the number of occupants increases from fewer than five to more than 10. In fact, 15-passenger vans (with 10 or more occupants) had a rollover rate in single vehicle crashes that is nearly three times the rate of those that were lightly loaded.

Among the NHTSA recommendations: 15-passenger vans should be operated by trained, experienced drivers and occupants should wear seat belts at all times (80 percent of those who died in 15-passenger van rollovers nationwide in the year 2000 were not buckled up).

NHTSA has reissued the advisory to specifically alert summertime users of 15-passenger vans and is considering the potential benefits of an additional compulsory warning label about rollover and seat belt use that would be visible to the driver and passengers of 15-passenger vans, respectively.

US federal law prohibits the sale of 15-passenger vans for school- related transport of high school age and younger students but no such prohibition exists for vehicles to transport college students or other passengers.