The National Highway Traffic Safety Administration (NHTSA) is again reminding all 15-passenger van users to take appropriate precautions to guard against the possibility of a tragic rollover crash.

Because 15-passenger vans are particularly sensitive to loading, the agency warns users never to overload these vehicles under any circumstances. NHTSA research shows overloading 15-passenger vans both increases rollover risk and makes the vehicle more unstable in any handling maneuvers. 

NHTSA research shows there is also a greater risk of rollover because many drivers lack experience driving the larger vehicles. Because 15-passenger vans handle quite differently than smaller passenger vehicles due to their increased length and width, NHTSA recommends only experienced drivers familiar with their handling should operate them.

Improperly inflated tires are another common contributor to rollover crashes. A recent NHTSA survey estimates that 30% of 15-passenger vans have at least one significantly under-inflated tire by 8 psi or more. Tire pressure can vary on front and back tires that are used for 15-passenger vans. This is why the agency urges vehicle users to make certain the vans have appropriately sized and load-rated tires that are properly inflated before every trip.

Taking into account the fact that tires degrade over time, NHTSA recommends that spare tires not be used as replacements for worn tires. In fact, many tire manufacturers recommend that tires older than 10 years not be used at all.

Here's a summary of the safety tips:

• Never overload the vehicle. Agency research shows overloading not only increases rollover risk but makes the vehicle more unstable in any handling maneuvers.

• Make sure the vehicle is regularly maintained, and that drivers are properly licensed and experienced in operating a 15-passenger van.

• Have suspension and steering components inspected according to the manufacturer's recommended schedule, and replace or repair these parts as necessary.

• Ensure that vehicles are equipped with properly sized and load-rated tires.

• Check the tires for proper inflation and signs of wear or damage. Correct tire size and inflation pressure information can be found in the owner's manual and on the door pillar.

• Finally, make certain passengers wear seat belts on every trip. A disproportionate number – 88% – of people killed in rollover crashes in 15-passenger vans were not wearing their seat belts.