Question What are placards? Answers Signs placed on a vehicle to identify cargo hazards A type of tire used in snowy conditions Logs kept inside the vehicle Journals for mileage Explanation Placards are diamond-shaped warning signs that are placed on the outside of vehicles carrying hazardous materials. Placards are used to identify the specific hazard classes of the cargo being carried. Take a FREE Practice Test Now This questions appears in the following tests: New Hampshire Knowledge Test Class A , Wisconsin Knowledge Test Class A , Georgia Knowledge Test Class B ,