Editor’s Note: Our talk of cars tends to be related to a wide variety of topics like speed, looks, comfort and fuel mileage. Yet often overlooked — both by enthusiasts and everyday drivers — is one of the most important factors: safety. This week, we’re taking a deeper look at how modern vehicles are keeping you and your loved ones safe on the road with our Automotive Safety Issue.
In 2012, there were over 5 million total car accidents in the U.S. That’s a staggering figure. So is the number of fatal accidents in the same year: 30,800. In those accidents, 45,637 vehicles were involved, and 33,561 people died either during the accident or in the aftermath.
Many of these deadly accidents involve the standard set of factors, like inclement weather, distractions like texting, or intoxication. Speed is typically a factor in an accident, though the speed at which drivers can now survive one of the most devastating accidents, a frontal collision, has increased thanks to improved structural and cabin safety technology, along with better impact-absorbing materials. In fact, evidence is mounting that points to the type of frontal collision as a grave contributor to whether passengers live or die.
Rarely is a fatal accident “clean” — a frontal impact hitting squarely with the entire area of a vehicle’s fascia. Many have been misled to think that full frontal impacts are the biggest killers, whether it’s with another car or a stationary object. (Just under half of all car crashes occur with another vehicle, and the next largest category is collisions with stationary, immovable objects like streetlights.) An off-set crash — where 25 percent or less of the fascia of the car collides with either another vehicle or a hard, stationary object and causes the car to pivot sharply — can also involve either other cars or a stationary object, and is especially lethal, accounting for a quarter of frontal crash deaths.
To understand why an offset crash is so deadly, we must understand its two major effects. The first has to do with the crumple zone, the largest of which is the front of the car, where the majority of cars house the engine. The crumple zone is designed to proportionately deform upon impact to absorb the energy from a crash, thereby reducing the degree of injury to passengers and the likelihood of death from injury. Generally, the longer the front of the car, the slower the car decelerates in a frontal accident; the longer this slow-down period, the better for passengers and drivers. As part of the crumple zone, the frame rails that extend along each side of the engine help to decrease the rate of deceleration upon impact. In a normal frontal crash, if the rate of speed is high enough, the impact can have deleterious effects on the actual cabin of the car, pushing the front components of the vehicle inward. But when only a small percentage of the front of the car hits the stationary object or another car — an off-set crash — the impact can miss the frame rails and reduce the effectiveness of the crumple zone more than just pure speed might. There’s only a fraction of the crumple zone left to absorb the impact, and deceleration time decreases in milliseconds, which can be the arbiter of life and death.
The way the car “clips” an immobile object or another car causes almost instantaneous rotation after contact, moving occupants rapidly to the side as well as forward.
The second deadly effect of the offset crash involves rotation. The way the car “clips” an immobile object or another car causes almost instantaneous rotation after contact, moving occupants rapidly to the side as well as forward. In crashes where rotation comes into play, occupants miss or glance off the front airbags and hit the center console, the pillars, the doors, or the windows. Even if immediate death or external injuries don’t occur, accident victims sometimes die after departing the accident due to internal injuries from hitting portions of the cabin. And it’s not just about cranial contact, either. Having your body get slammed against a hard surface can easily cause internal organ damage and serious internal bleeding that leads to death, if not immediately at the point of impact, then oftentimes hours later; these deaths are particularly acute in cases of off-set crashes.
Car manufacturers have caught on, responding by exceeding the federal requirements for dual front airbags in passenger cars since 1998 and light pickups since 1999: Now, many vehicles have side airbags for head and/or torso protection, driver knee airbags, curtain airbags for the side windows, and pillar airbags, despite the lack of any federal mandates for new vehicles. Though that’s all good news, it’s surprising that the Feds haven’t been more stringent about their requirements given the research by such widely recognized agencies like the IIHSA and the NHTSA. Of course, none of that technology negates the need for improving driving skills, decreasing the number of driver distractions and staying alert and awake on the roadways of America.