Unless you use airport shuttle vehicles, or belong to a church choir, sports team or other group that travels together, you probably figure you don't need to worry about the propensity of large vans to roll over when they're loaded with people.
But the conditions that can cause rollovers in extended-length full-sizes vans with up to 15 seats should also be a concern for anyone with a large SUV, especially in Canada where we tend to get lots of compromised road surfaces because of the weather
For sure the danger is more immediate in those big vans, as U.S. regulators made clear in a report on their safety of four extended-length full-size vans that come with either 12 or 15 seats.
From 1990 to 2002, the study shows, there were 510 rollovers and 725 fatalities, and despite the addition of safety devices over the years, the ratio of deaths per rollover was higher in 2002 (50 crashes and 70 deaths) than it was in 1990 (21 crashes and 23 deaths).
Overall, 62 percent of the deaths in 15-person van crashes were in single-vehicle incidents.
Those vehicles include three units that are still being built, including the Chevrolet Express 1-ton Extended, the Ford E-350 Super Duty XLT (Econoline and Club Wagons, and the Dodge Ram Van B3500/Wagon B350 that was discontinued in 2002.
By coincidence, the report from the National Highway Traffic Safety Association (NHTSA) came out just two days after three members of a church group from the Bronx area of New York were killed and nine injured when their van rolled over near Niagara Falls, Ontario.
As it was in most of the other crashes involving large van rollovers, the most recent incident was apparently made worse by the fact that most of the van's occupants were not wearing their seatbelts. This is true for any vehicle in any type of crash, but it bears repeating here because people in large vans do seem less inclined to buckle up.
For everyone on the road, the key message of the NHTSA study is that the chance of a rollover increases with number of people in the vehicle, particularly at speeds in excess of 80 kmh.
This is the result of a complex set of circumstances involving mass and the centre of gravity and can be compounded when people aren't buckled up and their weight can shift inside the vehicle. It also varies by vehicle type, with vehicle height being an important issue.
For 15-seat vans, the chances of a rollover with no one in the vehicle except the driver are actually lower than that of a large SUV with only the driver. Half-fill the large van and it's twice as likely to roll over, the NHTSA study found, and five times as likely to roll over if it's full.
The rollover rate above 80 kmh for cars with a full legal load or more goes up by a factor of 1.3, the rate for minivans under the same circumstances is 1.7, while SUVs and pickups are twice as likely to roll over.
This study clearly shows that a vehicle carrying its maximum load or more handles considerably differently under any duress and that the driver should behave accordingly.