The lines are among some 20 infrastructure projects worth 1.4 trillion baht ($40 billion) that the military government hopes to get underway before 2018.

The State Railway of Thailand is expected to open bidding for the projects in August and construction will likely start in February, Kobsak Pootrakool, vice minister at the Prime Minister’s Office, told reporters.

The proposed 25.9 km (16 mile) overground and underground dark red and light red lines will connect northern Bangkok to the city’s eastern suburbs and to the city centre.

It follows the approval of several rail lines in the traffic-jammed Thai capital this year.

“Once this project is completed, it will change the lives of people in Bangkok,” said Kobsak.

The two routes will take about three years to build and should be ready for passengers by 2020, Kobsak said.

Thailand’s transport minister expects large infrastructure projects to boost economic growth to 3.5 percent this year, adding about 0.3 to 0.5 percentage point to this year’s economic growth.

Fitch Ratings said earlier this month that there has been a lag in infrastructure development in Thailand since the 1997/1998 Asian financial crisis compared with neighbouring countries.

It expects infrastructure investment to increase over the next several years as the government prioritises such development.

The central bank in June kept its 2016 growth forecast for Southeast Asia’s second-largest economy at 3.1 percent.

($1 = 35.0100 baht)