Which of the following is a valid stopping distance for the parking brake test?

• A. 15 feet
• B. 20 feet
• C. 25 feet
• D. 30 feet

Answer: (B)

The parking brake test measures how reliably and quickly the parking brake can stop and hold the apparatus on level ground using a fixed distance. Twenty feet is the defined stopping distance for this test, chosen to provide a clear, repeatable measure of the brake’s effectiveness across different vehicles and loads. It ensures the parking brake engages promptly and can arrest movement within a practical range. If the vehicle takes longer than twenty feet to come to rest after applying the parking brake, the test indicates insufficient hold or a binding/adjustment issue. Distances like fifteen, twenty-five, or thirty feet don’t match the established criterion for this test.