01Evidence A

Always wear seat belts, both front and back

Wearing a seat belt in the front seat cuts the risk of dying in a crash by roughly half. For drivers and passengers in light trucks, the reduction is about 60%. Among U.S. crash victims in 2022 whose seat belt use was documented, half were not wearing one.

Cost

No cost at all. It only adds about 2 seconds to every trip…

Benefit

According to NHTSA estimates, seat belts lower the risk of fatal injury for front‑seat occupants of cars by 45…

Cost

No cost at all. It only adds about 2 seconds to every trip.

Benefit

According to NHTSA estimates, seat belts lower the risk of fatal injury for front‑seat occupants of cars by 45% and for those in light trucks by 60%. In 2022, half of the U.S. fatalities in passenger cars had no recorded seat belt use. The World Health Organization states that seat belts can reduce the risk of death inside a vehicle by up to 50%. WHO also estimates that in 2021, 248,099 people died in road crashes in China, which translates to 17.4 deaths per 100,000 people.

Original sources

NHTSA (2024). Occupant Protection in Passenger Vehicles: 2022 Data (DOT HS 813 573). https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813573 ; WHO (2025). Road traffic injuries fact sheet. https://www.who.int/news-room/fact-sheets/detail/road-traffic-injuries ; WHO GHO RS_196/RS_198 (China, 2021). https://ghoapi.azureedge.net/api/RS_196?$filter=SpatialDim%20eq%20%27CHN%27

Open source link
Book note

Seat belts must be worn in the back seat as well. In the same report, 60% of rear‑seat occupants killed in crashes were not wearing belts. The 45% and 60% figures are NHTSA estimates derived from crash‑database analysis (Kahane 2015), not from randomized trials. The Chinese death toll cited by WHO is a projection and is several times higher than official police statistics; the two figures cover different populations, so only the WHO estimate is used here.

My note