Each person offering (the shipper) a hazardous material for transportation by motor vehicle shall provide the carrier with the required placards unless the motor vehicle is already placarded. The carrier (driver) may not transport a hazardous material unless the required placards are affixed. [172.506]
In the case of rail shipments, each person offering (the shipper) a hazardous material for transportation shall affix the required placards to the rail car. [172.508]