The cabinet will be asked this month to approve two new train route extensions in the North and Northeast worth a combined 153 billion baht.
The routes are Den Chai-Chiang Rai-Chiang Khong in the upper North and the Ban Phai-Mukdahan-Nakhon Phanom in the upper Northeast.
The former will branch out from the main northern line in Phrae while the latter breaks from the upper northern line in Khon Kaen.
Transport Minister Saksayam Chidchob said the Den Chai route covering 326km will cost 85 billion baht to build and the Ban Phai route spanning 355km comes with a price tag of 68 billion baht.
He said the ministry will forward the two projects to the cabinet for approval some time this month. If and when the cabinet gives the go-ahead, a royal decree will be issued to expropriate the land where the routes will cut through, effectively marking the start of the projects.
Mr Saksayam also gave an update on the Bang Sue-Rangsit Red Line electric train construction. The minister said he was briefed by the State Railway of Thailand (SRT) that the project is estimated to be 10.3 billion baht over budget.
It was reported the budget had bloated mainly because the project design did not correspond to the actual cost of construction and that the bidding prices in the three contracts that make up the extended line were approved above the median price.
The Red Line extension was already exceeding its original budget set at 55 billion baht. The amount has been revised up to 93 billion baht, which will now be pushed up by a further 10.3 billion baht.
The project is supported by a loan from the Japan International Cooperation Agency (Jica).
The minister said the Bang Sue-Rangsit elevated extension is the fifth and last section of the entire Red Line which runs from Taling Chan to Rangsit.
For the Bang Sue-Rangsit extension, Mr Saksayam said the government has limited budget to invest in the project. The ministry thought it may be best to adopt a public-private partnership by granting contractors the right to operate the train under a 30-year concession.