Initial developments Line 3 dated back to 1998, when the Vietnamese government approved the 2020 vision Master Plan, which prioritise the building of a rail transit system, with a target to build 5 metro lines. Line 3 was one of the original lines considered in the master plan. Two separate preliminary feasibility studies was conducted in 2004 and 2005 with the help of the
Asian Development Bank to determine the viability of Line 3. Four options were originally considered: • An elevated metro line running from Nhổn depot to Swedish Embassy on Kim Mã Avenue, then running underground to Hanoi Station; • An at-grade tramway section between Nhổn and Ringway 3, then an elevated line to Swedish Embassy on Kim Mã Avenue, then running underground to Hanoi Station; • Similar to option 2, but the at-grade tramway would be converted to a dedicated metro line; • An at-grade tramway section between Nhổn and to Swedish Embassy on Kim Mã Avenue, then running underground to Hanoi Station. Out of all options, options 2 and 3 were eliminated from further consideration due to congestion and performance issues associated with a mixed circulation tramway system. Option 4 was discounted from further consideration because even though it involved a system operating on a partially dedicated route, significant adverse changes to traffic management were required, particularly at intersections and pedestrian crossings and it would have resulted in reduced operating efficiencies and travel times. As a result, option 1, which was forecasted to carry up to 458,000 people daily, was selected as the preferred option. The name and location of stations were finalized in the 2009 Final Feasibility Study. Based on this study, fifteen stations were reduced to 12 stations, 8 elevated and 4 underground. A twin bored tunnel concept using tunnel boring machines (TBM) was selected to tunnel 15 to 8 m underground and to utilize the centerline of existing surface roads. Two underground stations, Cát Linh and Văn Miếu, were relocated one block eastward to avoid cultural significant sites. == Budget ==