The Sky Train system was officially opened on 5 December 1999 by HRH Princess Maha Chakri Sirindhorn. It initially had lower than -predicted rider ship, with 200,000 passenger trips per day. Ticket revenue was only enough to meet the trains' operating cost, and not sufficient to service construction loans. However, the Sky Train's daily passenger numbers have steadily increased since then. On 9 December 2005, more than 500,000 single trips were made on the Sky Train in a single day for the first time. BTSC is planning to purchase more trains and is studying the possibility of putting 6-car trains into service. The company implemented a contactless ticketing system in 2007 named BTS SmartPass, and plans to allow both BTS and Suvarnabhumi Airport Link passengers to use their RFID smart cards as single ticketing system not before.The Bangkok Mass Transit System, commonly known as the BTS Sky Train is an elevated rapid transit system in Bangkok, Thailand. It is operated by Bangkok Mass Transit System Public Company Limited
( BTSC ) under a concession granted by the Bangkok Metropolitan Administration ( BMA ). The system consists of 32 stations along two lines: the Sukhumvit line running northwards and eastwards, ending at Mo Chit and Bearing respectively, and the Silom line which plies Silom and Sathon Roads, the Central Business District of Bangkok, ending at the National Stadium and Wongwian Yai. The lines interchange at Siam Station and have a combined route distance of 55 km. The system is formally known as the Elevated Train in Commemoration of HM the King's 6th Cycle Birthday .
Bangkok's first attempt at building an elevated rail network was the Bangkok Elevated Road and Train System, which was ended in 1998 after only 10% had been completed.
The BTS system ( the elevated metro system owned by BMA ) was initially referred to as the Lavalin Sky train because it was to be designed using the Vancouver Sky Train as a model adopting the technology developed by SNC-Lavalin. Due to political interference, the concession with Lavalin was cancelled in 1992, despite Bangkok's chronic traffic congestion. The Thai Government focused on increasing road and expressway infrastructure in an attempt to combat congestion. However, this had less than the desired impact as the number of cars on the road increased dramatically. The lines considered under the sky train project became later the basis for the Bangkok Metro system and interesting enough are mainly underground