What is the purpose of using placards when transporting hazardous materials?

The purpose of using placards when transporting hazardous materials is to provide immediate identification of hazards. Placards are vital for safety as they communicate critical information about the types of hazardous materials being transported. They are displayed on vehicles or containers and are designed to alert emergency responders, other drivers, and the public to potential dangers. This immediate identification helps ensure that appropriate safety measures are taken in the event of an accident or spill, facilitating effective emergency response.

The other options do not address the primary function of placards. Indicating a driver's experience level has no relevance to safety in transporting hazardous materials. Compliance with weight limits pertains to regulatory requirements but does not involve the identification of hazards. Maximizing fuel efficiency is unrelated to the purpose of placarding, which is strictly concerned with hazard communication and safety.