What does this sign indicate?

• Only passenger vehicles can use this road.
• Vehicles carrying hazardous materials are prohibited on this road.
• Vehicles carrying hazardous substances or toxins are allowed on this road.
  Explanation:

  "This sign specifies that vehicles transporting hazardous materials or toxins can use the designated road. These routes are typically selected for safe and efficient transport while minimizing risk to the public and the environment."
• Vehicles must avoid transporting any substances on this road.