Question Where must placards be placed? Answers Only on the front of a vehicle On the front, back and both sides of a vehicle Only on the driver’s side of a vehicle Only on the passenger's side of the vehicle Explanation If a vehicle is carrying hazardous materials that require placarding, there must be identical placards placed on the front, rear, and both sides of the vehicle. This questions appears in the following tests: Massachusetts Class B Knowledge Test New Hampshire Class A Knowledge Test New Hampshire Double North Dakota Class A Knowledge Test