Which organization is responsible for investigating transportation accidents in the United States?

• A. National Traffic Safety Board
• B. National Technical Safety Bureau
• C. National Training Safety Bureau
• D. National Transportation Safety Board

Answer: (D)

The National Transportation Safety Board is the organization that investigates transportation accidents in the United States. It operates as an independent federal agency and focuses on uncovering the probable cause of accidents and issuing safety recommendations to prevent recurrence. This investigation role spans multiple modes, including aviation, highway, rail, marine, and pipeline transportation. Note that its purpose is to investigate and improve safety, not to regulate or enforce rules—enforcement and rulemaking are handled by other agencies such as the FAA. The other names listed do not represent agencies responsible for this kind of investigation.