'CDL Class A Practice Test 2025 – The Complete All-in-One Guide to Passing Your Exam!'

Verifying the functionality of the service brakes during a moving test is essential for ensuring safety while operating a vehicle. The correct method involves moving the vehicle forward slowly and applying the hand brake. This process allows the driver to assess how effectively the service brakes are functioning in a controlled environment. When the vehicle is in motion, applying the hand brake will engage the brakes and provide immediate feedback on their responsiveness.

By slowly moving the vehicle, you can better gauge whether the brakes are engaging properly without risking loss of control. This action also allows the driver to feel the brake response and determine if the braking system is functioning as intended, ensuring it meets safety standards before operating the vehicle under more demanding conditions.

Other choices do not provide a practical approach for checking service brake functionality. For instance, engaging the hand brake at high speeds could lead to loss of control and potential accidents, while monitoring tachometer readings doesn’t assess brake effectiveness directly. Checking the air supply continuously, while important for air brake systems, does not directly verify the act of braking itself.