What codes apply when inspecting heavy-duty trucks over 17,000 pounds and trailers over 10,000 pounds?

When inspecting heavy-duty trucks over 17,000 pounds and trailers over 10,000 pounds, specific codes are applicable to ensure safety and compliance with regulations. The correct selection highlights the relevant codes that govern the inspections for these types of vehicles.

The codes identified as 3, 4, 6, and 7 are essential as they cover critical safety aspects crucial for heavy-duty vehicles. Typically, these codes may pertain to areas such as brake systems, tire conditions, vehicle lights, and structural integrity, all of which are vital for the safe operation of heavier vehicles on the road. Heavy-duty trucks have unique safety requirements due to their size and weight, which can significantly impact stopping distances, load security, and overall maneuverability.

In contrast, the other answer choices include combinations of codes that do not encompass the full scope necessary for accurate and comprehensive inspections of heavy-duty trucks and trailers. This distinction is important because compliance with the correct set of regulations ensures not only legal adherence but also the safety of the driver and others on the road.