Placards must be:

Placards must be displayed on all four sides of a vehicle transporting hazardous materials to ensure maximum visibility and compliance with safety regulations. This requirement allows first responders and others to quickly identify the presence of hazardous materials from any direction, which is crucial in emergency situations. The clear identification helps to mitigate risks associated with transporting such materials, as it provides essential information regarding the potential dangers involved.

In the context of hazardous materials transport, having placards on all sides ensures that regardless of how the vehicle is positioned in relation to other vehicles or obstacles, the appropriate warnings are visible. This practice is part of the broader regulatory framework designed to enhance safety and awareness on the road.