Which of the following is not a primary live load?

• A. Moving Vehicular Loads
• B. Live Load
• C. Primary Live Load
• D. Wind Loads

Answer: (D)

Loads on a bridge are categorized by how they behave and what causes them. Live loads are the forces that can vary with time and use, such as vehicles, people, and temporary equipment. A primary live load is the main live-load scenario used in design, typically the moving vehicular traffic that a bridge must carry. Wind loads come from wind pressure and are treated as environmental or wind loads rather than live loads. They don’t vary with occupancy in the same way and are assessed separately from live-load effects. So wind loads are not a primary live load. The other options describe actual live-load scenarios: moving vehicular loads illustrate a live load that moves across the bridge, and the general live load category includes these kinds of loads.