When is a placard required on a vehicle transporting hazardous materials?

A placard is required on a vehicle transporting hazardous materials when the quantity of those materials exceeds specified thresholds set by the Department of Transportation (DOT). These thresholds are determined based on the type of hazardous material being transported, as some materials pose greater risks and have lower threshold limits. The main purpose of placards is to inform emergency responders and the public of the potential dangers associated with the substances being carried.

While vehicle weight and classifications may play a role in the regulations surrounding hazardous materials, the key factor for placarding is the actual quantity of hazardous materials onboard. This ensures that proper precautions can be taken in case of an emergency.