Early plans A direct MRT link to Changi Airport was first announced in March 1976 during the planning of the MRT network. In May 1982, the plans showed an MRT branch to Changi Airport. The branch was to be built after the completion of the initial MRT network. In a 1983 feasibility study, the
Mass Rapid Transit Corporation (MRTC) concluded the level of passenger traffic was insufficient to justify such a branch. Plans for the connection were reviewed again in 1984 because the MRT system was built below budget. In 1985, a survey on transport patterns to the airport was conducted by an MRTC consultant team to assess the viability of an airport MRT connection. However, the consultants concluded in January 1986 that the connection was financially unfeasible in the immediate period because travellers preferred to commute to the airport by taxi. In the following year, Communications Minister
Yeo Ning Hong announced that the planned spur would be unfeasible despite the completion of Terminal 2. In March 1989, the
Member of Parliament for Changi, Teo Chong Tee, called for the airport extension, saying it would serve the increased passenger demand for the airport. In response, Minister Yeo said an extension would be considered if there were development plans in the Changi area. Otherwise, the low demand might not meet operating costs. In 1991, he stated a connection would only be justified when annual passenger numbers using Changi Airport reached 50 million, and projections said the airport would handle only about 34 million passengers per year at the beginning of the 21st century. The minister also claimed the airport was already well-served by expressways with affordable taxi rates. In 1992, Communications Minister
Mah Bow Tan said the government had already reserved the land needed for the possible route.
Finalisation of rail connection In August 1994, the proposal for a rail link was reconsidered after airport use grew by 10% annually, surpassing the previous projections of 6–7%. With plans for a new terminal to manage passenger growth, the
Civil Aviation Authority of Singapore (CAAS) urged the MRTC to reevaluate the proposal as they were concerned the roads serving the new terminal might be insufficient. The CAAS also suggested that the new link be built in tandem with the new terminal. The MRTC opened consultation studies on the airport link, which would branch off from the
East–West Line (EWL) at
Tanah Merah station but without intermediate stops. After another feasibility study by the
Land Transport Authority (LTA), Deputy Prime Minister
Lee Hsien Loong announced on 15 November 1996 that the branch would be built. The branch, which was projected to be completed in 2001, would run from Tanah Merah station and have an intermediate stop at Somapah (now
Expo) to serve the Changi Business Park and the exhibition centre. There were no plans to extend the branch towards the cargo-and-engineering complexes due to low demand in the area. Teo, who had been advocating for the branch since 1987, was "overjoyed" and considered the announcement an "excellent piece of news".
Construction and opening In October 1998, the contract for the construction of Changi Airport station was awarded to a joint venture between
Kumagai Gumi and Sembawang Engineering and Construction for . The contract included the construction of the station and associated tunnels, a new baggage tunnel between Terminals 2 and 3, and a new vehicular underpass to serve Terminal 3.
CPG Consultants, which was designing Terminal 3, provided 20 staff to assist the LTA team on the line extension. A groundbreaking ceremony was held on 29 January 1999. Speaking at the ceremony, Communications Minister
Mah Bow Tan said the station's construction would require close collaboration between stakeholders such as the LTA, CAAS and the contractors. The roads connecting to the arrival and departure halls of Terminals 1 and 2 were rerouted west of the station site during the construction. The east side of the station was constructed first due to more complex deep excavation works near developments such as Terminal 2. Extensive foundation reconstruction was required for the overrun tunnels as they passed through an irregular pile layout beyond the east side of the station. The LTA dismissed the idea of mining the tunnels as the works were in shallow ground. Instead, open-cut excavation within diaphragm walls and ground treatment methods were adopted. As part of the
President's Challenge 2001, part of the charity walk went through the tunnel between Expo and Changi Airport stations. Changi Airport MRT station opened on 8 February 2002, and the official opening ceremony for the line extension was held at the station on 27 February 2002. When the station opened, passenger traffic has been moderate because bus transportation continued to be a popular means of cheap, direct transport for local airport and airline employees, and for travellers not living along the EWL. Many air travellers preferred to continue taking taxis or private transport because not all of the trains on the MRT had luggage racks. Taxi drivers said the station put them at a disadvantage, reporting a loss of 20% in earnings within the first month of station operations. At that time, the station had a daily ridership of 20,500 commuters. Despite developments built around the branch line to boost further ridership, it was not deemed cost-effective to run
through services to the MRT. Since 2003, the branch was instead served by a shuttle service running from Tanah Merah to Changi Airport.
Incorporation into the TEL The possibility of extending the Eastern Region Line to Changi Airport via the airport's Terminal 4 was first announced by LTA in May 2013 when Terminal 4 was under construction. The extension would have provided a more direct connection from the airport to the city. The Eastern Region Line was later merged into the
Thomson–East Coast Line (TEL) in August 2014, and Transport Minister
Khaw Boon Wan said in July 2016 the TEL extension to the airport might be completed at the same time as Terminal 5. On 25 May 2019, the LTA confirmed that the Changi Airport branch line will become part of the TEL when it is extended to Changi Airport from
Sungei Bedok station via Terminal 5. This extension is expected to be completed in 2040. The contract for the construction of twin-bored tunnels from Changi Airport station to Changi Airport Terminal 5 was awarded to Shanghai Tunnel Engineering Co (Singapore) Pte Ltd for S$321.7 million (US$ million). Construction required tunnelling under a closed runway east of Terminal 2, which was completed in November 2022. On 29 April 2024, the LTA called a tender to modify the existing station, along with Tanah Merah and Expo stations, in preparation to integrate them into the TEL. ==Details==