Taiwan Taoyuan International Airport MRT (Mass Rapid Transit), commonly known as the Airport MRT, is a rapid transit line of Taoyuan Metro that connects the municipalities of Taipei, New Taipei, and Taoyuan with Taoyuan International Airport. The line, from Taipei Main Station to , has 21 stations and began commercial service on 2 March 2017. The line features Commuter and Express services as well as in-town check-in and baggage check at Taipei Main Station and at . An extension to Zhongli railway station via from the current terminus at is under construction, with the Laojie River metro station scheduled to open in July 2023 and the full extension scheduled for completion in 2028. Route The Taoyuan Airport MRT route starts from Taipei Main Station and heads west, passing through Sanchong, Taishan, Xinzhuang, Guishan, Linkou, and Luzhu before reaching Taoyuan International Airport, after which the route turns south to Taoyuan HSR station before terminating at in Zhongli. The route is currently long with 21 total stations, of which 6 are underground and 15 are elevated; approximately of the line is underground while the remaining is elevated. There are two maintenance depots along the line; Qingpu Depot (near ) and Luzhu Depot (near .) Operations Two types of services are offered: Commuter and Express. Commuter Trains have a blue livery and stop at all stations while Express Trains have a purple livery and focus on serving passengers using Taoyuan International Airport (TPE), stopping at just two stations between Taipei Main Station and the airport. Express Trains reach TPE from Taipei Main Station in 35 to 37 minutes depending on the terminal, with a 15-minute headway during peak times and a 30-minute headway off-peak. While nearly all Express Train services only run between Taipei Main Station and TPE, a few services during weekday rush hours and weekend afternoons run the full route to Huanbei with only one additional stop at Taoyuan HSR station, serving the entire route in 64 minutes. Commuter Trains have a 15-minute headway at all times and serve the full route in 82 minutes. Express Trains have transverse row seating with underseat storage for luggage as well as three luggage racks per car; Commuter Trains have longitudinal seating without underseat storage and only have two luggage racks per car. Both services feature free wi-fi as well as flight information display systems showing status of departing flights at TPE, although there