CDL Hazardous Materials Practice Test

Transporting Class A explosives involves strict regulations to ensure safety due to their highly dangerous nature. A placarded cargo tank is specifically designed to carry liquids, often hazardous materials that can react violently with explosives. The combination of a cargo tank's flammable contents with Class A explosives poses a significant risk of explosion or combustion, making it a prohibited scenario.

In contrast, other vehicle types like standard trailers, flatbed trucks, and dry vans, while they must still adhere to regulations regarding the transport of hazardous materials, do not inherently create the same level of risk when transporting Class A explosives. Therefore, the presence of a placarded cargo tank is what disqualifies that combination vehicle from safely transporting these types of explosives.