The Baht 60bn ($US 1.7bn) project was implemented by the Mass Rapid Transit Authority of Thailand (MRTA) under a public-private partnership (PPP) scheme, which was financed with a Japanese ODA loan.

MRTA awarded a contract in 2013 to Bangkok Metro Public Company (BMCL) for both the provision of the railway systems and operation of the 16-station line.

Ch Karnchang, Thailand, which is a shareholder in BMCL with MRTA, was responsible for the civil works while a joint venture of Marubeni and Toshiba was selected for the railway systems package which included rolling stock, power supply systems, signalling and control systems and communication systems.

Japan Transport Engineering Company (J-Trec), a subsidiary of East Japan Railway Company (JR East) has supplied a fleet of 21 three-car Sustina trains, which will be maintained by a local JR East subsidiary for the first 10 years of operation.

The Purple Line is forecast to carry around 200,000 passengers per day in the initial year of operation, rising to 400,000 passengers per day by 2019.

A free shuttle bus will operate between Tao Poon and Bang Sue station on the MRT Blue Line until a 1.2km western extension of the Blue Line between the two stations opens later this year.