Wearing safety belts snugly is essential for their effectiveness in protecting occupants during a vehicle crash or sudden stop. A snug seatbelt ensures that the restraint system functions as designed, limiting movement and preventing the occupant from being thrown around inside the vehicle or ejected from it.
Additionally, a snug fit ensures that the forces of a collision are distributed across the stronger parts of the body, such as the pelvis and ribcage, minimizing the risk of injury. If a belt is too loose, it can slide off the body during an impact, reducing its ability to provide protection.
The other choices indicate unsafe practices. Wearing the belt loosely for comfort compromises safety and increases the risk of injury. A safety belt should not be worn only across the lap, as this fails to protect the upper body and may lead to serious injury in an accident. Similarly, wearing the belt loosely across the shoulder is ineffective, as it can allow excessive motion and reduce the protective function needed during a collision. Therefore, it is clear that a snug fit is crucial for maximizing safety.