Cat Linh-Ha Dong metro line, which runs from Cat Linh to Ha Dong, starts commercial operation on November 6, 2021. (Photo: VNA)

The project also envisions 78 underground public parking lots with a total floor area of more than 104ha, mainly located in four inner districts. These parking facilities are designed to have 3- 4 floors.

The plan identifies 39 underground public space areas in the inner city with a total area of about 954ha. Underground public works serving different purposes such as services, trade, entertainment will be set up and there will be connections between these projects and urban railway lines and stations on the routes, Nghia said.

The plan also suggests 65 locations deemed to be ideal for the formation of underground space in new development areas in the north and south of the Red River spanning over 2,170ha.

According to Duong Duc Tuan, Vice Chairman of the municipal People's Committee, the underground space planning project requires high expertise and involves many ministries and agencies from the central to local levels because it is a large scale project and is carried out for the first time.

The approval of the planning project is the foundation for implementing other projects, gradually helping to turn Hanoi into a modern and civilized city, he said.