What is the difference between a posted load rating and a posted weight limit?

• A. Load rating specifies safe load-carrying capacity; weight limit restricts vehicle weight based on existing condition and restrictions for safety.
• B. They are the same thing.
• C. Weight limit is the maximum load the structure can support without any restrictions.
• D. Load rating is only for pedestrian bridges.

Answer: (A)

Load rating is the engineering assessment of how much load the bridge can safely carry given its current condition. It is a technical capacity value that reflects the structure’s ability to support traffic, considering factors like deck condition, wear, corrosion, and joints.

A posted weight limit is a legal restriction placed on the bridge to limit the weight of vehicles that may cross it. It translates the structural capacity into enforceable limits for traffic and can be influenced by the current condition, safety considerations, and vehicle configurations. It may be lower than the rated capacity to provide a safety margin and to address specific conditions or restrictions.

So the difference is that the load rating is the technical, safe-carrying capacity of the structure, while the posted weight limit is the enforceable maximum vehicle weight permitted to cross the bridge. The other ideas blur or misstate this distinction: they aren’t the same thing, they don’t describe a no-restriction maximum, and load ratings aren’t limited to pedestrian bridges.