During the 1980s AIDS hysteria then Surgeon General C. Everett Koop was asked for what advice he would give a couple going on a date. The interviewer expected him to say something about "safe sex." What he said instead was: "Use your seat belts."
Thirty years later because of mandatory seat belt laws and other measures about 86% of all Americans wear seat belts in vehicles. In contrast, about 50% of cops wear seat belts in their patrol vehicles. Officer safety trainers have even told me they have ridden with officers who are religious about belting in when driving their personal vehicles but never do so on patrol.
Many officers ride around without buckling up because of misguided beliefs. When many states established "click it or ticket" laws, they exempted emergency personnel. This exemption was written into these laws so that paramedics can work on people in moving ambulances. It was not intended to be a mandate that all emergency personnel should be ejected from their vehicles in case of accident. There's also the belief that an officer will be trapped in a patrol car by a jammed seat belt during an accident. This can happen, but it is easily addressed. Keep a seat belt cutter or knife within easy reach in your vehicle.
But the number one misguided belief that leads officers to endanger their lives by driving around without seat belts is the fear of being unable to get loose from the belt during an ambush. I'm not going to say this is beyond the realm of possibility, but I have spoken with dozens of officers and trainers about this issue over the years and not one can document a case of it happening. Besides, you can counter this concern very easily through training. Practice unhooking your seat belt as you roll to a stop at a scene. That way you won't be belted in inside your stopped car if someone should attack you.
Every law enforcement officer wants to go home safely at the end of his or her shift. There are several simple things you can do to substantially improve your chances of doing so. Wear your body armor. Don't drive at speeds beyond your capabilities. And use your seat belt.