Northeastern Line is a Railway line in Thailand, split from Northern Line at Ban Phachi Junction. It is divided into three lines:
Ubon Ratchathani Main Line, located in Phra Nakhon Si Ayutthaya Province, Saraburi Province, Nakhon Ratchasima Province, Buriram Province, Surin Province, Sisaket Province, Ubon Ratchathani Province.Nong Khai Main Line, located in Khon Kaen Province, Udon Thani Province, Nong Khai Province, Vientiane Prefecture.Lam Narai Branch Line, located in Lopburi Province and Chaiyaphum Province.Northeastern Line is one of the most important railway lines in Thailand because it is the first line that opened for passenger service, from Bangkok to Nakhon Ratchasima.
9 March 1891 - started construction26 March 1896 - opened Bangkok-Ayutthaya, so 26 March is Thai Railway Establishment Day.21 December 1900 - opened Ayutthaya-Nakhon Ratchasima1 April 1925 - opened Nakhon Ratchasima-Buriram1 August 1928 - opened Buriram-Sisaket1 April 1930 - opened Sisaket-Ubon RatchathaniSRT had also built a short railway line from Bung Wai to Ban Pho Mun, but the line was closed.
Later, SRT started to build Nong Khai Main Line.
1 April 1933 - opened Nakhon Ratchasima-Khon Kaen24 June 1941 - Khon Kaen-Udon Thani13 September 1955 - Udon Thani-Na Tha31 July 1958 - Na Tha-Nong Khai5 March 2009 - Nong Khai-Thanaleng, Vientiane PrefectureLater, SRT built another one railway line Lam Narai Branch Line, opened on 19 August 1967.
Ubon Ratchathani Main Line
Saraburi Station - Main Saraburi station, named Pak Priaw station until 1934.Kaeng Khoi Junction - The Bua Yai Line and Khlong Sip Kao line diverge from the mainline here. Main Depot with refueling facility. The point for dividing freight trains into two trains to pass difficult section of Dong Phraya Yen (Kaeng Khoi - Pak Chong) or combining divided freight trains back into one trainPak Chong Station - The gateway to Nakhon Ratchasima and the point for dividing freight trains into two to pass difficult section of Dong Phraya Yen (Kaeng Khoi - Pak Chong) or combining divided freight trains back into one trainNakhon Ratchasima Station - Main depot of the Northeastern Line with refueling facility and a branch line to 2nd Army Support Command. Main Nakhon Ratchasima station.Thanon Chira Junction - Junction for Nong Khai line close to Fort Suranaree (2nd Army Region HQ)Buriram Station - Buriram provincial station with a branch line to a quarry at Khao KradongSurin Station - Main Surin stationSi Sa Ket Station - Main Si Sa Ket station.Ubon Ratchathani Station in town of Warin Chamrap - Terminus of South Isaan Line (also known as Ubon Line) with Depot and refueling facility. Named Varindr station until 1942-1943. Main Ubon Ratchathani Station.Lam Narai Station- Station on the Lam Narai/Bua Yai Branch, for Chai Badan Municipality.Chatturat Station- Station on the Lam Narai/Bua Yai Branch, alight for Chaiyaphum.Bua Yai Junction - junction with refueling facilityKhon Kaen Station - Khon Kaen main stationUdon Thani Station - Udon Thani main station with refueling facility.Nong Khai Station in town of Nong Khai - Terminus of North Isaan Line (also known as Nong Khai Line), provides a connection to Thanaleng Station in Vientiane, Laos. Main Nong Khai station. 
