Define “seat belt compliance.”

Seat belt compliance refers to the extent to which vehicle occupants actually wear seat belts when the vehicle is in motion. This is a critical factor in road safety, as seat belts are designed to protect occupants in the event of a collision, reducing the risk of severe injury or death. High compliance rates indicate that more drivers and passengers are taking appropriate safety measures, which correlates directly with fewer injuries and fatalities in road traffic accidents.

The other options do not directly address the concept of compliance itself. The number of vehicle accidents (first option) reflects the overall safety performance but doesn't indicate individual behavior regarding seat belt use. The laws surrounding seat belt use (third option) provide the framework for enforcement and compliance but are not the behavior of wearing the belt itself. The design of seat belts (fourth option) is relevant to their effectiveness but does not speak to whether people use them as intended. Compliance focuses specifically on the action taken by individuals, making the understanding of "the extent to which occupants wear seat belts" the most accurate definition.