Question The trailer hand valve should not be used while you are driving because: Answers It will disconnect from the vehicle. You will stop the vehicle too quickly. It can cause a skid. Explanation Never use the trailer hand valve while operating your vehicle. Using the trailer hand valve while driving can cause your trailer to skid. Take a FREE Practice Test Now This questions appears in the following tests: Rhode Island Double , South Dakota Double , Arkansas Combination , Kentucky Combination , Missouri Combination , Ohio Combination , Oregon Combination , South Carolina Combination ,