How should a lap belt be worn for optimal safety?

Wearing a lap belt over the pelvis is the safest way to secure yourself in a vehicle. This positioning maximizes the effectiveness of the safety belt during a collision by providing stability and preventing injury to vital organs. When the lap belt is positioned properly over the pelvis, it helps spread the forces of a crash across the stronger parts of the body, such as the hips and thighs, reducing the risk of severe injuries.

In contrast, wearing a lap belt under the arm can lead to serious injuries, as it does not provide the necessary restraint and can cause internal damage during an accident. Similarly, positioning the belt across the abdomen is unsafe because it could compress abdominal organs and lead to injury in a crash. Placing the lap belt at the mid-thigh is also not effective, as it does not align with the body's structural strength needed for safety during sudden stops or impacts. Therefore, securing the lap belt over the pelvis is crucial for optimal safety in a vehicle.