D2 Subway is a proposed expansion of the DART Light Rail system in metropolitan Dallas, Texas, in the United States. The subway would run from the existing Victory station, tunneling underground through the central business district of downtown Dallas, and connect to the existing tunnel under Cityplace. Four new stations would be built along the new alignment. When service commences, the Blue Line and Orange Line would route through the D2 Subway alignment, thereby alleviating pressure along DART's Pacific Avenue and Bryan Avenue corridor, which all four lines currently share, and promoting system-wide growth in total capacity. The project is estimated to cost between $1.7 and $1.9 billion. History Proposals for a second downtown light rail alignment date back to DART's 1983 Service Plan to accommodate the interlining of multiple future corridors in the DART Service Area. This plan laid the groundwork for a goal of three potential corridors with a goal that the initial development focus on an east to west subway rather than an at-grade transit-way mall if funding allowed. However, after a failed bond vote in June 1988, DART's System Plan was modified through the 1989 DART New Directions Transit System Plan leading to the development of an, at-grade, surface transit-way along Pacific Avenue and Bryan Avenues, which is currently utilized. Planning by DART specifically for the D2 Subway alignment was officially initiated in 2007. Initial plans for the alignment called for the subway to surface near Deep Ellum station, which would have required demolishing the current station. In 2021 DART reconfigured the project's eastern approach to continue into the existing Cityplace/Uptown station tunnel, foregoing the planned surface junction near Deep Ellum. In February 2022, the Dallas City Council and DART Board of Directors each approved this new alignment. Description Route The project would begin south of Victory Station, diverting via a junction from the existing Green and Orange Line alignment, and traveling at-grade in a southeasterly direction within DART-owned right-of-way in the center of Museum Way crossing Victory Avenue, Victory Park Lane, and Houston Street. The alignment would continue through a parking lot directly south of the Northend Apartments and used by patrons and visitors of the Perot Museum of Nature and Science where the at-grade, Museum Way station, would be located. Upon leaving the station, the alignment would cross under Spur 366/Woodall Rodgers Freeway and after crossing McKinney Avenue, located on the other side of