Rail Audit Transparency Act This bill requires the Federal Railroad Administration (FRA) to provide Congress with notice of when a comprehensive safety assessment is being conducted on an intercity or commuter rail transit agency. Specifically, the FRA must (1) provide notice within 10 days after it initiates an assessment to specified congressional committees and each Member of Congress who represents a state in which the service that is subject of the assessment is located, and (2) report the findings of the assessment within 90 days after completion to such committees and Members.