My Personal Experience: I went to the State Railway of Thailand this year August 27, 2017, together with my sister. We went there to ride their train for the first time it's next to their airport. Bangkok is a easy city to travel as long as you read signs and codes thanks to their railways. They have unique token that use to enter or exit as you can hop in and hop out around the city.
State Railway Of Thailand
The State Railway of Thailand (SRT) is the state-owned rail operator in Thailand. The network serves around 44 million passengers per year. The SRT was founded as Royal State Railways of Siam (RSR) in 1890. Construction of the Bangkok-Ayutthaya railway the first part of the Northern Line, started in 1890 and opened on 26 March 1896. The Thonburi-Phetchaburi line later the Southern Line, opened on 19 June 1903. The SRT operates all of Thailand's national rail lines. Bangkok Railway Station-(Hua Lamphong Station)- is the main terminus of all routes.