"I'm New Jersey Governor Jon Corzine, and I should be dead."
Arguably one of the more important pronouncements of his political career, the then-governor issued these words in a public service announcement once he recovered from injuries suffered in a car accident on April 12, 2007 -- an accident in which he wasn't wearing his seatbelt. Corzine's body was slammed around the inside of his SUV after the vehicle collided with a guardrail at high speed. His injuries included a broken leg, 11 broken ribs, a broken sternum, a broken collarbone, a fractured lower vertebra, and a facial cut that required plastic surgery. He also required a breathing tube that kept him from resuming his duties as governor for several weeks.
Ironically, as a U.S. Senator in 2001, Corzine proposed that the federal government direct states to require children under age 16 to wear seatbelts.
Corzine's injuries point out why seat belts -- which prevent your body from crashing into a car's hard interior surfaces, or worse, from being ejected from the car -- are so important.
How seat belts work
To understand why it's so important to be belted in during a crash, it helps to break an accident down into slow motion.
First, there's the car's impact with whatever it hits. In the brief seconds it takes for the car to crumple and come to a stop, the passengers inside are still traveling at the same speed the car was going before the crash. If they aren't wearing seat belts, passengers keep hurtling forward until they collide with some part of the vehicle or other passengers -- the second stage of the collision. One police officer who has been a first responder at plenty of accidents says he's seen the unfortunate results of not wearing seat belts. He's seen people's knees get blown out from hitting the bottom of the dash under the steering column -- even when the driver's car was only going 35 mph. Another common injury he sees is shattered wrists, when the unbelted driver tries to hang on to the wheel at the point of impact, but momentum keeps his arms and body moving forward.
Even after the passengers' bodies have come to a stop, there is a third collision as their internal organs slam against their bones or other organs. According to the National Highway Traffic Safety Administration (NHTSA), this internal collision often causes serious injury or death. Think of a person's head hitting the dashboard -- while there might be a bruise or a bump on the outside, it's the brain colliding with the inside of the skull that can cause the real damage.
Seat belts are designed not only to keep you from being thrown from the car, but also to absorb the impact of a crash where your body can withstand it best -- in the bones of your hips, shoulders, and chest, according to the NHTSA. Seat belts also stretch slightly so your body doesn't stop as abruptly, and they prevent you from colliding with a part of the car or another person. A report from the University of Washington found that when used together, automatic shoulder harnesses and lap belts reduce your risk of death in a car crash by 86 percent. James Madison University also notes that seat belts, when used properly, reduce the number of serious traffic injuries by 50 percent.
One caution: Using a shoulder belt without a lap belt only reduces your risk of death by about a third, and can actually increase the likelihood of chest or abdominal injuries, so always use both.