What kind of placards must be displayed on vehicles carrying hazardous substances?

Vehicles carrying hazardous substances must display Proper Hazard Class Placards. These placards are essential for communicating the specific type of hazards associated with the materials being transported, allowing for quick recognition by emergency responders and other drivers. Each class of hazardous material corresponds to a specific placard design and color, which enables effective identification and response in case of an incident or emergency.

For instance, flammable materials may have a different placard than corrosive substances, reflecting their distinct risks. The use of these standardized placards helps to ensure safety during transportation by informing other road users and emergency services of the potential dangers involved.

Other choices, while potentially relevant to safety in different contexts, do not accurately represent the specific requirement for hazardous substance transportation. Restriction placards may indicate limitations imposed on transport but do not convey the nature of hazards. Emergency response placards are complementary but serve specifically for emergency personnel rather than for ongoing transport scenarios. Warning signs based on load type lack the standardized system needed for hazardous materials, which is why Proper Hazard Class Placards are the mandated choice.