The government will switch its railway investment from high-speed to medium-speed trains following strong criticism about the cost-effectiveness of the scheme, says Pansak Vinyaratn, chief policy adviser to Prime Minister Yingluck Shinawatra.
Medium-speed trains capable of 250 kilometres per hour carry a lower investment cost than high-speed ones and are suitable for product shipments, he said without elaborating.
A source said medium-speed trains will be used for the project's four routes.
They are Bangkok-Nong Khai, Bangkok-Chiang Mai, Bangkok-Hua Hin and Bangkok-Rayong.
The routes are the major part of the government's 2-trillion-baht megaproject investment over seven years.
Mr Pansak said the government should use a 1.435-metre track for the railways, as this standard gauge can conveniently connect with China's and Europe's rail systems.
The government has already spoken in depth with the Chinese government about high-speed railways that will be expanded to connect Thailand with Europe via China.
The Chinese government is in talks with the Turkish government to build railways there, and this will allow China's rail links to expand to Hamburg, Germany.
Thailand cannot shrug off railway development, as it will boost economic growth, Mr Pansak said.
"The Chinese government has been enthusiastic in developing its western and southeastern regions into new economic centres, and investment and trading opportunities for Thai investors will be widened if Thailand can link transport routes to the regions," he said.
"The Chinese government's plan to expand its high-speed rail network nationwide will also help Thai investors to penetrate widely into China."
With China's planned railways, Thailand could ship products to China and Europe in only 15 days rather than 45 days by sea.
Lightweight and high-technology products such as semiconductors can benefit the most.
Thai farmers and small entrepreneurs, especially online traders, can also enjoy benefits.
Under the project, Thailand will link with China through the Bangkok-Nong Khai route.