Which of the following documents would you check to report a dangerous cargo item on a highway?

The bill of lading is the correct document to check when reporting a dangerous cargo item on a highway. A bill of lading serves as a legally binding contract between the shipper and the carrier, and it provides essential details about the shipment, including the nature of the cargo, the quantity, and any specific handling instructions, especially for hazardous materials. It is a critical document that ensures all parties involved have accurate information about what is being transported, which is vital for safety and regulation compliance.

Other documents, while related to transportation, do not hold the same relevance in this context. For instance, a waybill typically provides information about the shipment but does not serve as a contract of carriage like the bill of lading. An air bill is specifically used for air transport and wouldn't be appropriate for highway transport scenarios. A dangerous cargo manifest, while relevant for certain forms of transport, is not standard for highway shipments; it is more commonly associated with maritime transport or special handling scenarios. Therefore, the bill of lading is the most appropriate choice for this situation as it directly pertains to terrestrial freight operations and the legalities surrounding hazardous materials.