[5] An extension to Zhongli railway station via Laojie River from the current terminus at Huanbei is under construction.

The Laojie River metro station opened in July 2023 and the full extension is scheduled for completion in 2028.

[10] While nearly all Express Train services only run between Taipei Main Station and TPE, a few services[note 2] 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.

[18] Since October 2018, a NT$10 promotional discount on all published one-way fares has been applied due to the operational profitability of the line since service began.

[19] 30, 60, 90, and 120-day periodic tickets allowing unlimited rides on the Taoyuan Airport MRT within specified station pairs are available, priced at a 30, 35, 40, or 50% discount, respectively,[20][21] on the price of 21 published round-trip fares between the specified station pairs per 30-day period (21 being the approximate average number of weekdays per month).

Taoyuan Metro uses a specialized fleet of engineering trains supplied by Hokuriku Heavy Industries for maintenance of way.

[31] A rail system to connect Taoyuan International Airport with existing transportation hubs was proposed as early as the 1980s[32] and reemphasized over the years in government proclamations such as the New Ten Major Construction Projects.

[7] After the BOT project failed to go through, the Ministry of Transportation and Communications (MOTC) decided to build the line directly from the government budget.

MOTC originally planned for the line to be transferred to the Taiwan Railway Administration (TRA) to operate; President Ma Ying-jeou had also proposed the Bureau of High Speed Rail (BOHSR)[note 3] to operate the line with the Taipei Rapid Transit Corporation (TRTC) and the TRA.

The two sides eventually compromised, agreeing to the underground platform proposal but with the Taipei City Government covering the additional cost.

[36] The BOHSR of the MOTC oversaw construction,[38] which began in 2006 and was scheduled for completion in 2013 but was plagued by multiple delays.

[43] The design of core E&M systems (including rolling stock, power supply, signaling, communications, depot equipment, platform screen doors, etc.)

and the design and construction of two depots (Qingpu and Luzhu) were awarded as part of a contract worth NT$25.5 billion.

[16] Hitachi, in cooperation with Marubeni Corporation[44] and Kawasaki Heavy Industries, won the bid for the E&M systems and signed the contract on 12 January 2006.

[45] The groundbreaking ceremony for the power supply system was held on 1 October 2010 on behalf of five contractor companies including Hitachi.

The main RC structure was completed in March 2011, while civil engineering was finished at the end of October.

[27] A large portion (78.6%) of the route length is constructed on 9.3 m (30 ft 6 in)-wide viaducts, which is used in both dense urban districts as well as rural areas with steep slopes.

A 4 m (13 ft 1 in) noise barrier wall is used on all viaducts, and floating track beds are used for environmentally-sensitive zones.

During construction, some residents in Xinzhuang expressed concern over the 7 to 9-story high elevated track and its stability during potential earthquakes.

[7] Since shield tunnels were constructed underneath existing taxiways and the control tower area, an automatic system was integrated to monitor any soil and structure impact in real-time so that immediate response could be taken to any disruption.

The section passing below Tamsui River (about 1 km (0.62 mi) in length) employed the shield-tunneling method.

In order not to delay opening of the rest of the Taoyuan Airport MRT, space along the line was reserved for future construction of the proposed station.

[63] As of 2020, the planned station is named Erchong and is in the final approval stages with the Taoyuan City Government.