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. This questions appears in the following tests: Arkansas Air Brakes Massachusetts Air Brakes Massachusetts Air Brakes Mississippi Class A Knowledge Test New Hampshire Air Brakes New Jersey Air Brakes North Dakota Double North Dakota Air Brakes South Carolina Air Brakes South Carolina Air Brakes Tennessee Passenger