How many identical placards must be placed on a vehicle? Do you currently have car insurance? Insurance is mandatory to drive in Ohio Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question How many identical placards must be placed on a vehicle? Answers Three Two Four Explanation A placarded vehicle must have at least four identical placards: one on the front, one on the rear, and one on each side of the vehicle. This questions appears in the following tests: Kentucky HazMat Kentucky HazMat Maine HazMat Maine HazMat Michigan HazMat Ohio HazMat Ohio HazMat Oregon HazMat Rhode Island HazMat Utah HazMat