To provide additional funding for the Washington Metropolitan Area Transit Authority and improve upon the Washington Metropolitan Area Transit Authority Compact, and for other purposes.

WMATA Improvement Act of 2017 This bill authorizes the Department of Transportation to provide additional grants for each of FY2018-FY2028 to the Washington Metropolitan Area Transit Authority (WMATA) for financing approved capital and preventive maintenance projects. No grants may be provided until: the WMATA Board of Directors certifies that amendments have been made to the existing collective bargaining agreement between WMATA and a collective bargaining unit allowing WMATA to implement necessary operational changes required to provide a high level of service, reliability, and safety as well as lower costs through competitive bidding for certain capital improvements; and the WMATA Compact includes amendments requiring WMATA Board members to have a primary fiduciary obligation to WMATA, newly appointed Board members to have at least one of specified expert qualifications, and the Board to be composed of nine voting members, including the CEO of the Transit Authority and two appointed by each of the District of Columbia, Virginia, Maryland, and the Secretary of Transportation. Congressional consent for the Compact shall be withdrawn if Compact signatories (the District of Columbia, Virginia, and Maryland) fail to enact such amendments.