The project aims to encourage young people to consider living outside the city and starting families, as Seoul has the world's lowest fertility rate.

Long commutes and expensive housing in greater Seoul, home to half the population, are major reasons for the low birth rate.

The government has attempted to boost births through subsidies, but with little success.

The GTX, a 134 trillion won ($99.5 billion) project, will provide six underground lines linking Seoul to outlying areas by 2035.

President Yoon Suk Yeol inaugurated a new section of the GTX line in South Korea, reducing commute time from Suseo to Dongtan from 80 minutes to 19 minutes.

The line, set to go into service on Saturday, will be one of the fastest underground systems in the world with trains traveling up to 180 km per hour.

The shorter commute will enable people to spend more time with their families.

The high cost of owning a home in South Korea, with median prices reaching a peak in June 2021, has made Seoul particularly expensive.

The GTX is expected to allow young people to consider homes further from the capital without long commutes.

A government official announced plans for a high-speed rail line, GTX, which could help reduce commuting time for workers in South Korea.

The official believes this will give people more leisure time with their families.

However, some analysts warn that the rail line could contribute to the decline of rural areas by attracting more people to the overcrowded capital.

Professor Kim Jin-yoo suggests that to revitalize struggling rural towns, similar infrastructure should be developed in those areas as well.