Which agency oversees the training and certification of bridge inspectors?

The National Highway Institute (NHI) is the correct choice because it is specifically designated as a part of the Federal Highway Administration (FHWA), which is responsible for providing training and certification programs related to the inspection of bridges. NHI offers various courses designed to enhance the skills and knowledge of bridge inspectors, ensuring that they are well-prepared to assess bridge safety and condition effectively.

While other agencies mentioned, such as the Federal Aviation Administration, the American Society of Civil Engineers, and the Department of Transportation, play important roles in their respective fields, they do not specifically focus on the training and certification of bridge inspectors like NHI does. The DOT does oversee transportation infrastructure, but it is NHI that directly facilitates the necessary training programs for bridge inspection, which is why it is the agency that rightly answers this question.