Question When traveling down a steep downgrade: Answers The air brakes should be used. The vehicle should be placed in a low gear and the driver should use engine braking. The driver should continually downshift instead of using the brakes. Explanation On long and/or steep downgrades, you should primarily use engine braking to control the speed of your vehicle. Use your brakes only as a supplement to this effect. Take a FREE Practice Test Now This questions appears in the following tests: Idaho Knowledge Test Class A , Vermont Knowledge Test Class A , Alaska Air Brakes , Arizona Air Brakes , New Hampshire Air Brakes , North Carolina Air Brakes , Washington Air Brakes ,