Using the trailer hand valve while driving: Question Using the trailer hand valve while driving: Answers Will help you turn safely. Will stop your trailer safely. Can cause a skid. Is impossible. Explanation Never use the trailer hand valve while operating your vehicle. Using the trailer hand valve while driving can cause your trailer to skid. This questions appears in the following tests: Connecticut Combination District Of Columbia Combination Georgia Double Georgia Combination Kansas Combination Massachusetts Combination North Carolina Combination North Dakota Tank North Dakota Combination South Dakota Combination Texas Combination Wisconsin Combination Wyoming Combination