Safety of SUVs

When SUVs first entered the scene, their tendency to rollover during accidents created a stigma; no one wants to drive a car that tends to fatally injure occupants in a crash. In the years since, technology has improved SUV safety to the point of involving less driver deaths than cars of similar weight. In fact, from 2005 through 2008, there were 28 driver deaths per million registered SUVs in the U.S. versus 56 driver deaths per million for cars. Pickup trucks had 52 driver deaths per million for the same time period. Looking at these numbers, you could say that SUVs are even safer than cars. So how did such a turnaround happen?

First, let's look at the physics. SUVs typically weigh more and ride higher than cars. This is both a good thing and a bad thing; good because this offers more protection in a crash, and bad because the higher center of gravity causes the vehicle to roll onto its roof more easily. These rollover accidents are a major source of severe injuries to passengers.

To combat this problem, car manufacturers developed new technologies and implemented new designs to decrease the chances of a rollover, as well as reduce injuries should a rollover occur anyway.

Electronic stability system. This prevents conditions that could cause a rollover. If you lose control, the system will limit acceleration and apply antilock brakes to keep the vehicle on course. It can't prevent a rollover entirely, but it can prevent the circumstances that generally lead to a rollover. This feature has been so effective that most automakers have made it standard on SUVs, and the NHTSA now requires it for 2012. Some advanced models can even detect an occurring rollover and take action to stop the motion.

Improved body design. Automakers have lowered the overall center of gravity, making SUVs more stable naturally. How did they do this? By building the SUV on a car frame, creating the now-popular crossover.

Side curtain airbags. In a rollover or side impact accident, these deploy from the ceiling to cover the side windows. They stay inflated long enough for several rolls to protect occupants and keep them in the car. Flying out of the car is a main cause of death in rollover accidents, so this feature has greatly reduced the mortality rate of rollover accidents.

All of these advances are wonderful at keeping passengers safe, but what about occupants of the other car in a crash? In recent years, automakers have lowered SUV frames so that in an accident, the powerful SUV frame will engage a car's crumple zones rather than the cabin. This change alone has reduced fatalities among the other car's drivers by 21 percent in head-on impacts and by almost 50 percent in a side-impact crashes.

In addition, SUVs typically have large blind spots. To overcome this problem, many SUVs now offer a sonar-based "park assist" system to indicate proximity to an obstacle or person. Or, a rear backup camera automatically offers a wide-angle view behind the vehicle when the transmission is shifted to Reverse.

By David Lacrisse