Missouri Permit Test 1 Question Seat belts: Answers Should not be worn. Are optional for those holding a CDL. Are required, but only if a driver is transporting hazardous materials. Are required to be used by all drivers. Explanation You must wear a seat belt at all times while operating a CMV. Answer Statistics 1.32 % of our users get this question wrong. This questions is relatively Easy. Missouri Permit Test This questions appears in the following tests: Indiana Knowledge Test Class A ,