Question When transporting hazardous materials, placards: Answers Should be lit up. Should be used on all four sides of the vehicle. Should be used only by Class A licensed drivers. Explanation When required, hazardous materials placards must be placed on all four sides of a vehicle transporting hazardous materials. Take a FREE Practice Test Now This questions appears in the following tests: Iowa HazMat , Louisiana HazMat , Nevada HazMat , Oregon HazMat , Rhode Island HazMat , Tennessee HazMat , Virginia HazMat ,