The government is expected to formally ask Japan to jointly invest in a 500-billion-baht high-speed rail project when a high-ranking Japanese delegation visits Bangkok later this month.
A source in the Transport Ministry said the high-speed rail development scheme linking Bangkok and Chiang Mai requires Japan's partnership to materialise.
Prime Minister Prayut Chan-o-cha is likely to propose that both countries invest in the 673km high-speed rail scheme when he meets a special adviser to the Japanese prime minister in the middle of the month, said the source.
The move follows the signing of the memorandum on cooperation for the high-speed rail project between Transport Minister Arkhom Termpittayapaisith and his Japanese counterpart Keiichi Ishii in August.
Under the cooperation agreement, the high-speed rail project, the first of its kind in Thailand, will adopt Japan's shinkansen system with both countries expected to work on a basic plan next year after the Japan International Cooperation Agency (Jica) releases a final report on the results of the feasibility study tentatively in February.
A similar joint-investment proposal was raised with China for the dual-track Bangkok-Nong Khai route but it hit a snag and the government decided to scale down the project to the Bangkok-Nakhon Ratchasima route and changing it from a double to single track.
However, the Bangkok-Nong Khai rail development scheme has been recently revived pending talks between Thailand and China.
Pirapol Thawornsupacharoen, deputy transport permanent secretary, said Japanese authorities handed over preliminary findings of the Japanese-Thai rail development project to Mr Arkhom during their Nov 29 meeting.
According to the findings, five potential routes for the scheme have been suggested along with development plans along the routes and rail stations to stir economic activity.
He said the Thai side has asked the Japanese delegation to recommend the best route that could link with the Bang Sue central station, investment models, and sources of financing.
Japan is expected to present the full report to the Thai government in February next year with outlines of the pros and cons of each route and of the investment models, said Mr Pirapol.
"We're asking them to also consider sources of funding, interest rates, and investment models. But Japan hasn't committed itself to investing in the project. They are working on the full report," he said.
According to Mr Pirapol, the framework for the Thai-Japanese rail project remains unchanged.
The Japanese working committee will submit a final report in February which will be forwarded to concerned agencies for review before it goes to the cabinet tentatively in March or April next year.
The Bangkok-Chiang Mai rail is 673km long with estimated investment costs of 546.7 billion baht. The 380km stretch between Bangkok and Phitsanulok is likely to be built first at an estimated cost of 277.4 billion baht. The remaining stretch covers 293km from Phitsanulok to Chiang Mai.
Mr Pirapol said the Japanese working panel has also proposed a cargo transport development plan covering construction of inland container depots (ICD) and the setting up of a cargo transport firm with the State Railway of Thailand (SRT).
He said the SRT has asked the Japanese working panel to conduct a detailed study covering expected returns, cargo transport volumes and investment models of the cargo transport firm.
The details are set to be released in February next year.