How often are routine NBIS bridge inspections required?

• A. Every six months for all bridges.
• B. At least every 24 months (two years) for routine inspections; annual for fracture-critical members.
• C. Every two years for all inspections.
• D. Only when a problem is reported.

Answer: (B)

Routine NBIS inspections are a scheduled safety check with a defined cadence. The minimum interval for routine inspections is every 24 months for bridges in the NBIS program, while fracture-critical members require an annual inspection due to their higher risk if they fail. So, routine inspections occur at least every two years, with fracture-critical components checked once a year. The other options don’t fit because inspections aren’t required every six months for all bridges, aren’t universally every two years without the extra annual fracture-critical check, and aren’t only done when a problem is reported.