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The government of Thailand has reaffirmed its plans to tender four light rail projects in the coming months. The projects are key parts of the Transport Ministry's US$3.2 billion infrastructure development plan for 2018 and will be developed through public-private partnerships.

The light rail lines will be located in Phuket, Chiang Mai, Khon Kaen and Nakhon Ratchasima.

Phuket is the most popular tourist destination in the south of the country, and also a commercial and trading centre. Its light rail line will link the airport with the inner city and Phangnga province to the north. A feasibility study for the project has been completed. It proposed a 60km line covering 23 stations, requiring an estimated investment of THB24 billion (US$743 million). 

Chiang Mai is the biggest city in northern Thailand, a commercial centre also very popular with tourists. The feasibility study for the light rail line to be located here assessed two options: a 35km route that would run both above and below ground, with estimated costs of THB107 billion (US$3.3 billion), and a 40.57km route, above-ground only, requiring a total investment of THB28.9 billion (US$895 million). 

The Khon Kaen light rail project is undergoing an environmental impact assessment. The line will have 18 stops, spanning 22.6km. The current plan aims to make island platforms for trains on Mittraphap Road, running from the Tha Phra locality to the Samran locality in Khon Kaen's Muang district. 

The project's value is estimated at THB15 billion (US$464 million). Its development has been considerably advanced by the Khon Kaen Think Tank (KKTT) Group, set up by 20 local business tycoons in January 2015. The group was set up to be a vehicle to collaborate with Khon Kaen University to develop strategies for urban development. The resultant Khon Kaen Model is a transit-oriented development strategy, with a light rail line being its main feature.

A design for Nakhon Ratchasima's light rail project has been completed by the Office of Transport and Traffic Policy and Planning. The estimated cost of the design is THB15 billion ((US$464 million).

Given the two options for the project in Chiang Mai, the total value of the projects is between THB82.9 billion (US$2.6 billion) and THB161 billion (US$5 billion).

Local press have speculated that the government aim to complete the tenders before the general election in November 2018. This aligns with the Transport Minister's statement in November 2017 that the projects would begin construction in 2018.

Plans are for the four projects to be funded through the government’s public-private partnership program (PPP), and investors will be fast-tracked through the process at the direction of Deputy Prime Minister Somkid Jatusripitak, the Transport Minister said. The Phuket line should be the first to break ground.

Aside from relieving traffic congestion, the PPPs are also intended to spread development and economic stimulus more evenly throughout the country as opposed to being concentrated solely on Bangkok or the Eastern Economic Corridor just east of the capital.

The Khon Kaen and Nakhon Ratchasima rail lines are in the north-east, where development has lagged. None of the four cities or provinces has any mass transit rail lines despite their relatively large populations, steady expansions, and increasing commercial importance.