D2 Subway

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 the highway, the alignment would begin its transition underground through the "west tunnel portal", passing under Hord Street near the Dallas World Aquarium and remaining underground until reaching Interstate 345. The alignment continues south under Griffin Street and between San Jacinto Avenue and Elm Street, an underground station, Metro Center station, would be located providing access for transfers to buses at DART's West Transfer Center or access to the Red and Blue Lines at West End and Akard stations.

After crossing under Main Street, the alignment would turn east under the Belo Garden and continue under Commerce Street. While under Commerce Street, a second underground station, Commerce Street station, would be located between Akard Street and Ervay Street.

Before passing under South Pearl Street, the alignment would begin to turn northeast, crossing diagonally underneath existing buildings and structures. A third underground station, CBD East station, located between Main Street and Elm Street would provide access for transfers to additional buses at DART's East Transfer Center.

The alignment would continue traveling in a northeasterly direction and after passing under Cesar Chavez Boulevard, the alignment would begin the transition back to the surface at the "east tunnel portal" and emerge at-grade, crossing Hawkins Street just a block east of Interstate 345 and encounter a wye junction allowing trains to continue either in a northern or southern direction. The wye junction would be located at the current location of Deep Ellum station, requiring it to be relocated a block north. The new station would be renamed Live Oak station and be served by the Orange Line, solely, as it travels north past the wye junction and eventually converge on to the Red and Blue Line alignment. The Green Line would serve the Deep Ellum area with service at Baylor University Medical Center station and continue along its existing alignment.

The project will include five new DART stations, two at-grade, and three underground, which will all contain center platforms and introduce fare barriers. From east to west, the stations are:[2]

• Museum Way, located southwest of the Perot Museum and north of Woodall Rodgers Freeway. The station will consist of side platforms.
• Metro Center, located under North Griffin Street between San Jacinto and Elm Streets and would contain a mezzanine level, a public concourse level, and a center platform level accessible from up to four street-level entrances. A headhouse located at DART's West Transfer Center would be the primary entrance for passengers.
• Commerce, located under Commerce Street near AT&T’s headquarters, and the Magnolia and Adolphus hotels. The primary entrance for the station would consist of a headhouse at Pegasus Plaza located at the southeast corner of Main Street and Akard Street as well as access from two additional street-level entrances.
• CBD East, located between Main and Elm streets just east of South Pearl Street. The primary entrance for the station would be a headhouse at Elm Street and South Pearl Street as well as access from an additional street-level entrance.
• Live Oak, located in the median of Good Latimer Expressway, south of Live Oak Street.

The project would shift Green and Orange Lines service from the existing Pacific Avenue and Bryan Avenue transit mall to the D2 Subway corridor, maintaining their current terminals. The Red and Blue Lines would continue to operate on the existing transit mall. The system would continue to operate at 15-minute peak headways and 20-minute off-peak headways and with the same span of service from approximately 3:30 AM to 1:30 AM. Based on core capacity needs, an additional Red Line service would be added during peak hours from Cedars station to Parker Road station to address crowding. Services would continue to operate with two- or three-car length trains and not require an additional increases in fleet size beyond the current 163 Kinki Sharyo SLRV cars.

Trains on the corridor would average 16 mph, with a maximum speed of 22 mph between Museum Way station and Metro Center station with 30 second average dwell times.