Question If driving a truck that requires a CDL for operation: Answers You do not need to wear a seat belt. You are required to wear a seat belt, but only if transporting more than 500 pounds of cargo. You are always required to wear a seat belt. You are only required to wear a seat belt when driving a tank trailer. Explanation For safety, you must wear your seat belt at all times while operating a CMV. Take a FREE Practice Test Now This questions appears in the following tests: Colorado Knowledge Test Class A , Massachusetts Knowledge Test Class A ,