What is a critical criterion for a vehicle to transport hazardous materials?

A critical criterion for a vehicle transporting hazardous materials is that it must require a placard. This requirement is vital for safety and regulatory compliance. Placards are signs that indicate the presence and type of hazardous materials being transported. They serve to alert emergency responders and the public to potential dangers associated with the cargo in case of an accident or spill. The use of placards helps ensure that all parties involved understand the risks and can take appropriate precautions.

While features like clearance lights, vehicle weight, and pressure requirements may also play a role in the overall safety and functionality of the vehicle, they do not specifically indicate or communicate the presence of hazardous materials the way placards do. Thus, the necessity of placards is distinctly critical for identifying and managing the transport of hazardous materials.