I have 30 years as a FireFighter / Paramedic
I can say that I have never unbuckled a dead person.
I have worked in the rural and urban and suburb areas and therefore I have seen many kinds of accidents dealing with a just about every kind of moving vehicles - farm implements, cars/trucks - planes - trains - helicopters - subway's - boats / ships and all kinds of various industrial vehicles.
Dealing with all ages of patient population.
I HAVE NEVER UNBUCKLED A DEAD PERSON !
With exception of aircraft accidents involving high speed and altitudes - please read on for the explanation.
To those you say that you can just jump out of the way - I and or my fellow medics will get to practice our trade in some form in your future-job security,
thank you I need the job.
To those that are involved in a T bone type accident - This is the most lethal type of Impact You can sustain if you are the one that is struck in the side as previously stated all the energy is transfered to your car - eventually you.
To those that say they do not wear the seatbelt when only around town/neighborhood - The majority of all accidents are within 10 miles of one of those involved. 25 mph head on collision is equal to the force of 50+ mph crash. Now just imagine the force applied to the body actually grows exponentially as the speed and mass increase.
Now in my current stage of my career, I now teach new firefighters and medics and now investigate emergency vehicular accidents.
I also agree that adults should be free to make a choice so long as that decision and its results do not affect others either directly and or indirectly.
So yes the govt. that tells you to wear your seatbelt is looking after the greater populous.
But just remember nobody ever needs the fire dept./ems/police, because they did something smart! 