The Nhon-Hanoi Station route, the capital's second metro line, will run 12.5 kilometers from the western district of Nam Tu Liem via Kim Ma Street to the downtown railroad station, 8.5 km on the surface and the rest underground.
Work on it began in 2010 at an estimated cost of $1.2 billion, but several delays ballooned that to $1.55 billion.
The line is now 78% complete, while the elevated section is almost finished, and is awaiting assessment for the start of commercial operation late this year.
The underground section was 33% complete as of April. Work on it was suspended by the South Korean-Italian joint venture contractor Hyundai E&C-Ghella since July 2021 due to lack of land and only resumed in September last year.
Hanoi's first metro line, also the country's first, between Cat Linh and Ha Dong, became operational in November 2021.