Dynamic Load Allowance is described as:

• A. The process of considering dynamic effects of loads during service life
• B. A method to compute dead load
• C. A procedure to estimate construction duration
• D. An index to evaluate corrosion

Answer: (A)

Dynamic load allowance is the factor used to account for the dynamic effects of moving loads on a bridge during its service life. When vehicles travel across a structure, their loads aren’t applied steadily; accelerations, braking, and suspension create impact and dynamic amplification that exceed the static weight alone. Designers use this allowance to increase the live-load component, obtaining a dynamic (or impact) load that the structure must resist. This is how real traffic conditions are reflected in the design, ensuring safety under dynamic demand. It isn’t about dead load, construction duration, or corrosion indices.