When NBIS findings are used to determine maintenance actions, how is redundancy considered?

• A. Redundancy is considered along with severity and expected life.
• B. Redundancy is ignored.
• C. Only oldest elements are chosen.
• D. Redundancy is irrelevant.

Answer: (A)

The important idea here is that NBIS-based maintenance decisions use a risk-aware approach that weighs multiple factors, not just how bad a condition looks. Redundancy means the bridge’s ability to keep functioning even if a component or path fails—essentially, are there alternative load paths or backup capacity?

When engineers determine maintenance actions, they assess how severe the deterioration is, how long the element can continue to perform before needing major work (expected life), and how much redundancy the structure has. If redundancy is high, the bridge can tolerate some deterioration without immediate risk, so maintenance can be prioritized with a bit more leeway. If redundancy is low, even moderate deterioration can compromise safety or service, leading to earlier or more substantial maintenance actions.

So redundancy is considered alongside severity and expected life to guide priorities and actions.