seatbelts

Seatbelts are a vehicle restraint system designed to secure occupants in their seats during a crash, reducing body movement, distributing collision forces across stronger parts of the skeleton, and preventing ejection from the vehicle. They typically use a woven strap, a buckle, and a rollover-stable retractor anchored to the vehicle structure.

The standard modern belt is the three-point design, crossing the lap and the chest. Earlier cars used lap belts only. Some vehicles include rear shoulder belts or additional locking pretensioners that tighten the belt at impact and load limiters that allow some belt slack to reduce chest load. Anchors and adjustability vary by model.

Seatbelts dramatically improve survivability in crashes. In frontal crashes, belt use reduces the risk of fatal injury for front-seat occupants by roughly 45-50% and lowers the chance of serious injuries. Belts also help position occupants for airbags to work effectively and reduce the likelihood of ejection.

Legal and safety contexts vary by country and region. Many jurisdictions require belt use, with primary enforcement in some places and secondary enforcement in others. Children and infants generally must use appropriate restraints, such as car seats or booster seats, depending on age and size.

Maintenance and proper use: inspect belts for fraying or damage, replace after a crash, and ensure buckles latch securely. The belt should be worn with the shoulder strap crossing the collarbone and the lap belt low on the hips; avoid routing it under the arm or behind the back. Do not modify the belt system.