Metro Safety, Accountability, and Investment Act of 2019 This bill reauthorizes funding to the Washington Metropolitan Area Transit Authority (WMATA) contingent on certain changes to its governance and operations. The bill reauthorizes capital and preventive maintence grants to WMATA for FY2020-2029 as well as additional funding for capital and preventive maintence projects and the WMATA Inspector General (IG). The Department of Transportation (DOT) may not provide any amounts to WMATA until certain conditions are met, including that DOT (1) certifies that the WMATA Board of Directors has passed a resolution that reaffirms the IG as an independent and objective unit, (2) establishes and maintains the Jeanice McMillan Washington Metropolitan Area Transit Authority Track Safety Task Force, (3) establishes and maintains a Keith Dodson Washington Metropolitan Area Transit Authority Bus Safety Task Force, and (4) certifies that the WMATA General Manager has implemented procedures that establish documented policies and procedures for the capital planning process and require WMATA to improve the transit asset management planning process.