This bill directs the Inspector General of the Department of Transportation to conduct a comprehensive audit of federal funds allocated to certain public transportation entities. The audit will specifically examine the five largest public transportation agencies , identified by their 2019 unlinked passenger trips, that received federal funding under various applicable laws. It will cover funds distributed during the five fiscal years prior to the bill's enactment , including allocations from Chapter 53 of Title 49 and significant COVID-19 relief legislation like the CARES Act and the American Rescue Plan Act. The Inspector General is required to detail the exact amounts of funds received by each agency and provide a thorough description of how those funds were utilized . A report summarizing these audit findings must be submitted to Congress within 180 days , aiming to enhance accountability and transparency in federal transportation spending.