What does SRS stand for on many automotive airbag labels?

On many automotive airbag labels, SRS stands for Supplemental Restraint System.

The phrase reflects the airbag’s intended role: it supplements the seat belt rather than replacing it. During a collision, sensors send information about impact angle and severity to an electronic controller, which decides whether to trigger one or more airbag modules. The cushion then inflates within milliseconds and deflates after absorbing energy.

Early airbags were sometimes promoted as alternatives to shoulder belts, but the industry moved toward integrated belt-and-airbag protection. Mercedes-Benz offered an airbag with coordinated belt tensioning on the 1981 S-Class, helping establish the modern meaning of a supplemental restraint system.

SRS can refer to a vehicle’s broader airbag and pretensioner network, not merely the steering-wheel bag. Depending on the car, it may include frontal, side, curtain, knee or other modules. A dashboard warning marked SRS therefore indicates a restraint-system fault, not simply a problem with the horn or steering wheel. Airbags are passive restraints because they deploy without the occupant taking an action, but they are designed to work with properly worn belts.