Each state determines its seat belt laws. Some states require all occupants to buckle up while others require seat belt use only in front seats. Additionally, these laws can authorize primary enforcement, allowing law enforcement to stop and cite a driver specifically for not wearing a seat belt. Secondary enforcement laws allow officers to cite drivers for non-compliance, but only when they are pulled over for another primary violation.
According to NHTSA, the greatest jump in belt use occurred between 1984 and 1987 as seat belt laws took effect in 29 states. Research affirms that seat belt laws significantly increase seat belt use and that primary enforcement laws are more effective than secondary enforcement laws. In 2019, 92% of front-seat occupants in states with primary enforcement laws buckled up, in contrast to 86.2% of front-seat occupants in states with secondary enforcement or no laws.
The effect of seat belt laws on rear-seat occupants is also noteworthy. In 2018, 81% of occupants in back seats used belts in states with seat belt laws for all seating positions, while 68.7% of occupants in rear seats used belts in states with front-seat-only belt laws.
New Hampshire and American Samoa are the only state and territory without a seat belt law for adults. However, New Hampshire is currently considering a secondary adult seat belt law for all seats.
With the boom in ride-hailing services, there is heightened interest in rear seat belt usage in for-hire vehicles. Most states exclude taxi drivers and riders from seat belt requirements. Some states explicitly require passengers in for-hire vehicles to buckle up.
In Massachusetts, taxi and livery drivers are not required under state law to wear a seat belt, but passengers are. Oregon’s safety belt law requires occupants of privately owned commercial vehicles transporting 15 or fewer persons to use belts, including passengers in shuttles, taxis, limousines and vans. Nevada expressly requires taxi drivers and adult passengers in the front and back seats to wear a seat belt, allowing a $25 citation for violations and requiring taxi operators to post signs informing passengers that they must buckle up. New York recently amended its seat belt laws to require passengers older than 16 to buckle up in the back seat of for-hire vehicles. Previously, only passengers in the front seat were required to do so. New York also passed a bill mandating that all stretch limousines be equipped with one seat belt in the rear for each passenger by Jan. 1, 2023.