Line 6 (Beijing Subway)

Line 6 was originally planned to be an east–west line passing under Chaoyang Avenue continuing straight westward. However, this alignment would make the central section of Line 6 tunnel extremely close to the Forbidden City. Issues of historic conservation and protection were raised against the proposed alignment. To avoid damaging cultural relics in the area, the entire western and middle section of line 6 was shifted 1.5 km (0.93 mi) northward to Ping'an Avenue, forming the route of Line 6 today.[20][21] As of October 2007, Line 6 was planned to feature both express and local stations, but those plans have not been incorporated into the construction of Phase I.[22] Line 6 started construction on December 8, 2007, as one of the "horizontal" east–west lines of the "three-ring, four horizontal and five vertical and seven radial" Beijing Subway masterplan.[23] Construction is planned in three phases, the first phase in central Beijing, followed by extensions into the eastern and western suburbs.

Route map of Line 6 Phase I

In Phase I, Line 6 runs 30 km (19 mi) from Haidian Wuluju in Haidian District to Caofang in Chaoyang District following Linglong Road, Sanlihe Road, Chaoyang North Road, the west bank of the Grand Canal, and Yunhe East Road. In Phase I, there were 21 stations, including Erligou station, which opened on 18 March 2023.

Construction began in December 2007 and was completed in 2012. On March 22, 2010, the tunneling work on Line 6 commenced near Shilipu in Chaoyang District.[24] Total investment for Phase I was estimated at ¥19.7 billion.[15]

Line 6 in Phase I was originally slated to have elevated tracks for 7 km (4.3 mi), east of the 5th Ring Road, from Dingfuzhuang and Changying. After residents along the route raised concerns about train noise, planners reconsidered and ultimately decided to keep all of Phase I underground.[25][26][27] This made the first phase of Line 6 completely underground.[28]

Route map of Line 6 Phase I & Phase II

As of November 2010, plans for Phase II contained plans for distinct express and local stations.[29] In Phase II, which opened in 2014, Line 6 was extended further east by about 12.8 km (8.0 mi) through six stations from Caofang to Lucheng in Tongzhou District. Beiyunhedong station opened on 30 December 2018. Like Phase I, the Phase II track is entirely underground.

The extension was designed to have express and local services using passing tracks at select stations.[30] However, due to a shortage of rolling stock, express services have yet to be implemented when the Phase II opens in 2014. In 2018, the government announced that sufficient rolling stock had arrived to begin implementing an express service.[31][32] Express services started operating on March 31, 2020.[9]

Route map of Line 6 Phase I & Phase II & Phase III

Line 6 was originally planned to terminate at Cishousi station with Line S1 continuing the line westward. In 2011, because of issues of low capacity and electromagnetic radiation concerns of Maglev technology, city planning authorities proposed to detach several stations from Line S1. This would extend Line 6 for 10.556 km (6.559 mi)[33] west with six stations from Jin'anqiao to Haidian Wuluju (the western terminus of Phase I).[34][35] All stations are underground.[36] This replaced the Line S1 section between Cishousi and Pingguoyuan station.[37] Later the plan was revised with Line 6 being further extended westward beyond Pingguoyuan to Jin'anqiao station, paralleling Line S1.[36] The revision was formalized and submitted to the National Development and Reform Commission for review in March 2012.[36] Phase III opened in 2018, along with Beiyunhedong station, a Phase II station.

Plans for an interchange with Line 1 at Pingguoyuan were delayed by a renovation of the station. When Line 6 Phase III entered operation, Pingguoyuan station was not opened. In December 2021, the station was opened as an interchange between Line 6 and Line S1. The station for Line 1 will open in 2024.

The one-station Southern extension of Phase II from Lucheng to Dongxiaoyingnan will be 2.066 km in length.[19] Construction started on 30 August 2022. It is expected to open in 2025.[18]