What is the required braking capability for trailers and semitrailers when their gross weight exceeds 4,500 pounds?

The requirement for trailers and semitrailers with a gross weight exceeding 4,500 pounds is that they must have brakes that can be applied by the driver. This is essential for ensuring safe operation while towing, as it allows the driver to have direct control over the braking of the trailer or semitrailer. This ability to apply brakes from the vehicle helps in situations where immediate stopping power is required, enhancing overall safety on the road.

The capability also promotes effective coordination between the towing vehicle and the trailer, reducing the risk of accidents due to insufficient braking force in emergency situations. Having brakes that can be independently managed by the driver is crucial for large trailers, as their size and weight can significantly impact stopping distances and maneuverability.

Other options, while related to safety, do not adequately address the specific requirement for braking capability in this context. Emergency brakes, brake lights, and anti-lock braking systems serve important roles in vehicle safety, but the primary requirement outlined in the question specifically pertains to the driver’s control over the braking system of larger trailers and semitrailers.