Department of Transportation (DOT) Placards are required by law if you are shipping dangerous or hazardous materials. Promote the safe transportation of hazardous material. Identify and manage the risks presented by transportation of hazardous materials in commerce. The Hazardous Materials Regulations (HMR) is issued by the Pipeline and Hazardous Materials Safety Administration and governs the transportation of hazardous materials by highway, rail, vessel, and air. The HMR address hazardous materials classification, packaging, hazard communication and emergency response information. Placards help you comply, through the communication of this information, accidents are either altogether avoided or emergency responders are properly prepared to respond to a given incident. Click on images for more information.