How do NBIS findings relate to the decision to close a bridge?

• A. NBIS Findings Never Influence Closure Decisions.
• B. NBIS Findings Have No Bearing On Temporary Safety Measures.
• C. Closure Decisions Are Based Only On Weather Conditions.
• D. NBIS Findings Inform Close Decisions; Closures May Be Required If Defects Pose Immediate Danger.

Answer: (D)

NBIS findings are the safety signal for a bridge’s status. They document the actual condition of critical structural elements and identify defects that could affect load-carrying capacity or stability. When NBIS results reveal defects that pose an immediate danger, the responsible agency must close the bridge or impose strict restrictions to protect the public. If the defects are not immediately dangerous, authorities may implement temporary safety measures, such as load limits or speed restrictions, and plan repairs without a full closure. Weather conditions can influence how risk is managed, but closures are driven by the structural conditions revealed by NBIS, not by weather alone.