Which load category is associated with moving vehicles?

Which load category is associated with moving vehicles?

• A. Torsion
• B. Dead Load
• C. Primary Live Load
• D. Secondary Live Load

Answer: (C)

Moving vehicles impose variable, time-varying forces on a bridge, which are classified as live loads rather than permanent weights. Among live loads, the primary live load represents the main traffic-induced forces the structure must carry in normal service. This category governs the design checks for typical bridge use because it captures the largest, most consistent moving-load effects due to vehicles. Dead loads are the fixed weight of the bridge itself, while secondary live loads cover additional or less dominant moving loads (such as pedestrians or special temporary loads) that aren’t the main design traffic. Torsion is a type of internal stress, not a load category.

Moving vehicles impose variable, time-varying forces on a bridge, which are classified as live loads rather than permanent weights. Among live loads, the primary live load represents the main traffic-induced forces the structure must carry in normal service. This category governs the design checks for typical bridge use because it captures the largest, most consistent moving-load effects due to vehicles. Dead loads are the fixed weight of the bridge itself, while secondary live loads cover additional or less dominant moving loads (such as pedestrians or special temporary loads) that aren’t the main design traffic. Torsion is a type of internal stress, not a load category.