How must trailers and semitrailers ordinarily perform braking when their gross weight exceeds a specified limit?

When a trailer or semitrailer exceeds a specified gross weight limit, they must ordinarily be equipped with braking systems that provide adequate stopping power and reliability to ensure safety. In many cases, manual brakes can be essential for larger trailers or semitrailers because they allow for direct control by the driver, ensuring that the braking system engages effectively according to the vehicle's speed and load conditions. Manual braking systems are designed to activate when the driver engages them, which can provide a necessary balance of control and force.

In terms of performance requirements, manual brakes must often adhere to safety regulations that define the necessary stopping distances for heavily loaded vehicles. This ensures that operators can effectively manage their braking needs, particularly in emergency situations where precise control is vital. As such, manual brakes provide the necessary responsiveness and effectiveness required for trailers and semitrailers operating over a certain weight limit.