Question Air brakes are: Answers An effective tool for stopping large vehicles. Prohibited on large vehicles. Only effective in poor weather. A tool to improve fuel efficiency. Explanation As long as the brakes are properly maintained, using air brakes is a safe and effective method of stopping large, heavy vehicles. Take a FREE Practice Test Now This questions appears in the following tests: District Of Columbia Knowledge Test Class A , Tennessee Knowledge Test Class A , Maryland Knowledge Test Class B , Massachusetts Knowledge Test Class B , Indiana Air Brakes , New Jersey Air Brakes , South Carolina Air Brakes ,