Which of the following is a way to decide which placards to use?

Using the materials hazard class is essential when deciding which placards to use because placards serve as visual warnings that communicate the type of hazardous materials being transported. Each hazard class has specific placarding requirements set by the Department of Transportation (DOT) to ensure safety during transportation. For instance, flammable substances require different placards than corrosive materials. This classification helps emergency responders quickly assess the situation in case of an accident or leak, facilitating the proper handling of the hazardous materials involved.

The other options, such as time of day, driver’s experience, and weather conditions, do not have a direct influence on the appropriate placards needed. While these factors may impact other aspects of transport safety, they do not determine how materials are classified or which placards are necessary, making them secondary considerations to the material hazard class when it comes to placarding requirements.