According to the National Highway Traffic Safety Administration (NHTSA), seat belts reduced the risk of fatal injury to front-seat passengers by 45% in 2020. Seat belts also reduced the risk of serious injury to front-seat passengers by 50%.
Furthermore, a study by the Insurance Institute for Highway Safety (IIHS) found that seat belts reduce the risk of being ejected from a vehicle in a crash by 75%. Being ejected from a car greatly increases the chances of death according to the NHTSA.
These studies consistently show a correlation between people who wear seat belts and decreased fatalities or severe injuries on the roadways.