Do you currently have car insurance? Insurance is mandatory to drive in California Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question Which type of brakes do most heavy-duty vehicles have? Answers Air brakes Solid brakes Liquid brakes Gravity brakes Explanation For safety, most heavy-duty vehicles are equipped with dual air brake systems. Take a FREE Practice Test Now This questions appears in the following tests: Alabama Knowledge Test Class A , Mississippi Double , Georgia Air Brakes , Illinois Air Brakes , Indiana Air Brakes , Massachusetts Air Brakes ,