After an extensive debate and an engineering review on their suitability for use in the ARL project—and demands for compensation from Hopewell—the SRT eventually decided to demolish the pillars and build new ones.

[5] Originally scheduled to be completed by 2007, the Hopewell debacle, an extended bidding process, and a series of legal challenges from squatters and property owners who had encroached on SRT's land, repeatedly delayed the project.

In October 2021 operation of the line was transferred to a new special-purpose vehicle led by the consortium of Charoen Pokphand (CP) Holding and partners including Ch.

[8] As of May 2018, the daily average is around 72,000 passengers and overcrowding is still a major problem during peak periods due to insufficient rolling stock with only 7 of the 9 trains operational.

[10] On 1 June 2011, additional Express Line services became available between Phaya Thai station and the airport with a journey time of 18 minutes.

Subsequently, in September 2014 the SRTET decided to suspend the Makkasan Express due to low passenger numbers and insufficient rolling stock.

From 4 January 2011, a baggage check-in service began for passengers traveling on flights operated by Thai Airways, 08:00–21:00.

[13] The SRTET stated that they wanted to encourage further airlines to use the City check in service in early 2014 with a target of 1,000 people a day by late 2014.

[14] However, in July 2014 the SRTET stated that it would most likely cease check-in operations as only 10 people were using it a day with only 200 pieces of luggage checked in each month.

The line is 28.6 km (17.8 mi) long and is elevated, running above the existing eastern railway, with an underground terminal at the airport.

[16] The only significant difference from the UK units is a much larger air conditioning pod on the roof, providing extra cooling to cope with the Thai climate.

As with other Class 360 units, the trains were built in Krefeld, Germany – and were delivered from 2007, and testing in Bangkok began in March 2008.

[17] On 15 May 2012 the Thai Cabinet approved a budget of 5.2 billion baht for the SRT to order seven new, four car sets of Siemens Desiro rolling stock to be delivered by 2014.

In 2017, the SRTET commenced refurbishment of the four Express trains to install seating in the fourth car in order to increase passenger capacity.

[22] This was subsequently delayed with the SRT expecting to conduct an e-tender in April 2015 with a schedule to sign the contract by June 2015.

In early 2017, the SRT Deputy Director stated that the new rolling stock would be tendered and a contract signed by the end of 2017.

[24] Since its inception, the ARL was intended to be extended north to the new Krung Thep Aphiwat Central Terminal and ultimately Don Mueang International Airport (DMK).

However, the Thai Cabinet designated a two-airport policy in March 2012 encouraging airlines, particularly low-cost carriers, to move to Don Mueang Airport.

The ARL was intended to be the backbone of a future high speed rail line (HSR) to Chonburi and Rayong – originally scheduled to be completed by 2018.

In 2017 that the Thai Government decided that the new Eastern high speed line would originate at Don Mueang Airport, and not Krung Thep Aphiwat Central Terminal.

In early 2018, the SRT stated that the Eastern HSR line section from Phaya Thai to Krung Thep Aphiwat and Don Mueang Airport is expected to be tendered by May 2018 with a 4 months auction period before the successful bidder is awarded.