The extension comprises the 25.9km Light Red Line (Bang Sue-Phaya Thai-Makkasan-Hua Mak) and the Dark Red Line (Bang Sue-Hua Lamphong) which are scheduled to open in 2020.
Mr Kobsak Phutrakul, assistant minister to the Prime Miniter’s office, said the two Red Line routes would help to solve traffic problems for commuters travelling into Bangkok.
Construction of the suburban rail lines will include elevated, at-grade and underground stations, with the bids expected to be called next month. Construction is scheduled to begin in February 2017 and be completed in 2019.
The projects are expected to generate an economic internal rate (EIRR) of 34% and a financial internal rate of return (FIRR) of 13.5%.
State Railways of Thailand (SRT) is responsible for the Red Line project, while the Budget Bureau and the Finance Ministry were assigned by the cabinet to provide loans for construction.
The extensions will connect to the 15km Bang Sue-Taling Chan Light Red Line which is already completed but not in operation, and the Bang Sue-Rangsit segment of the Dark Red Line which is under construction.