The Thailand government plans to construct 2,506 km of HSR linking northern Chiang Mai, north-eastern Nong Khai, south-eastern Rayong and southern Padang Besar with Bangkok by 2036. The master plan is expected to entail an investment of THB 1.57 trillion.
The four projects to be implemented during 2017-21 are the 253 km Phase I of China-Thailand cooperation project, the 355 km Phase II from Nakhon Ratchasima to Nong Khai on the Thai-Lao border, an HSR linking Suvarnabhumi, Don Mueang and U-Tapao airports and its further extension to Rayong, and the 380 km Bangkok-Phitsanulok HSR. The projects to be implemented during 2022-26 include the 211 km Bangkok-Hua Hin HSR and the 288 km HSR from Phitsanulok to Chiang Mai. Further, during the third period from 2027 to 2036, Thailand plans to extend the Bangkok-Hua Hin HSR by 424 km to Surat Thani and then another 335 km to Padang Besar on the Thai-Malaysia border.