Line 2 (Shanghai Metro)

Line 2 is an east–west line in the Shanghai Metro network. With a length of nearly 64 km, it is the second longest line in the metro system after line 11. Line 2 runs from in the west to  in the east, passing Hongqiao Airport, the Huangpu river, and the Lujiazui Financial District in Pudong. With a daily ridership of over 1.9 million, it is the busiest line on the Shanghai Metro. The eastern portion of the line, from to Pudong International Airport, was operated almost independently from the main segment until April 19, 2019, when through service began. The line is colored light green on system maps.

History
The first section of line 2 was opened on October 28, 1999, from to. This section, which included 12 stations, totaled 16.3 km. A year later coinciding with the tenth anniversary of the development and opening up of Pudong, marking the official opening of the line, was added to the eastern part of the line, adding 2.8 km. Four new stations, located west of the Zhongshan Park station, opened in December 2006, extending the line to. This section added 6.15 km to the line. Four years later, in preparation for the 2010 Shanghai World Expo, the line was significantly expanded. In February, the Zhangjiang Hi-Tech Park station was rebuilt. In addition, another eastern segment took line 2 to. A month later, the line was extended westward to, adding 8.0 km to the line including a stop at. On April 8, an eastward extension added 8 stations to the line, totaling 26.6 km and taking line 2 to. On July 1, opens to the public with the opening of the railway station of the same name.

In October 2006, it was decided to rename three stations on line 2 by the end of the year, adopting a new naming scheme: metro stations, unlike bus stops, are no longer supposed to be named after neighbouring vertical streets, but famous streets and sights in the vicinity, making it easier for visitors to find these places. The renamed stations are Century Avenue (formerly Dongfang Road), East Nanjing Road (formerly Middle Henan Road) and West Nanjing Road (formerly Shimen No. 1 Road).

Up to April 19, 2019, when an eight-car train started serving the whole line 2 in a regular schedule, the east section of line 2 was served by a four-car fleet. Line 2 had a piecewise service pattern during morning peak hours whereby the suburban segment between Guanglan Road station and Pudong International Airport station is partially served by a four-car fleet in addition to the regular eight-car fleet serving the whole line. Already since 28 December 2018, during off-peak times, an eight-car fleet from East Xujing or Songhong Road station may terminate at Pudong International Airport station, but most trains still terminate at Guanglan Road station or Tangzhen (only during peak hours).

East Xujing to West Nanjing Road
The line begins at at the intersection of Xumin East Road and Zhuguang Road. The line heads northeastward under Xumin East Road for about 0.8 km before veering off the road and heading east, passing under Huaxiang Road. The line then enters the interchange station serving the. This station is an interchange with line 10. Shortly thereafter, the line enters the. line 2 then turns northward until it meets Tianshan Road and turns east again, roughly running parallel under Tianshan Road. Along this road, the line enters the, , and stations. At the, line 2 veers away from Tianshan Road, heading northeastward. The line then enters the along Changning Road, an interchange with lines 3 and 4. The subway line then runs parallel under Changning Road for a short distance before heading east under Yuyuan Road. Along Yuyuan Road, there is a station at, an interchange to line 11. East of this station, the line swerves away from Yuyuan Road and runs under Yongyuan Road, which merges into West Nanjing Road, where line 2 enters the, an interchange to line 7. Just before entering the, the metro line veers away from West Nanjing Road to Wujiang Road. Line 2 comes back under the road shortly thereafter.

West Nanjing Road to Longyang Road
East of the, line 2 heads eastward along West Nanjing Road, passing under the South-North Elevated Road. It then turns northeast into the, and interchange with lines 1 and 8. East of the People's Square station, the subway line moves under East Nanjing Road to the. Leaving the Huangpu District of Shanghai, the line heads under the Huangpu River and enters the Pudong New Area of Shanghai. The metro line passes the Oriental Pearl TV Tower and the World Finance Center near its station at. The line then runs under Century Avenue and heads southeastward to the. Line 2 then heads to the, the largest interchange station that serves lines 4, 6 and 9 as well. Line 2 continues southeastward along Century Avenue to the. From here, the line turns southward through Century Park to the. From here, the line turns southeast and then east as it enters the, an interchange with lines 7 and 16 as well as the Shanghai Maglev Train.

Longyang Road to Pudong International Airport
From the, the metro line heads eastward. Line 2 heads eastward, running under Zuchongzhi Road to the station. The line heads northeastward under Zuchongzhi Road to the and  stations. Line 2 then veers away from Zuchongzhi Road and heads under the Waihuan Expressway to the and  stations, turning south. Heading southward, it heads through the and turns back east, running under Chuanhuan Road. Line 2 then passes through the. Heading away from Chuanhuan Road, the metro line then enters the and  stations along Huazhou Road before turning southeast. Line 2 then begins running parallel to the Shanghai Maglev Train as it runs under the Yingbin Expressway and enters the. From here, line 2 continues south to its terminus at the, which serves Shanghai Pudong International Airport.

East expansion
As part of the phase IV extension of Shanghai Pudong International Airport terminal T3 will be built south of the current terminals T1, T2 and satellite terminal. The terminal T3 will be served by extending line 2 south by one station.

West expansion
Construction started on a one station west extension from to Panxiang Road in June 2021. The Panxiang Road station is south of the on line 17, these are separate stations and will not have an interchange. The extension of Metro line 2 to the west will improve the connection of the Hongqiao business hub to the city center and Pudong.

Station name change

 * On 28 October 2006, Dongfang Road was renamed as the after station renovation for line 2 and the opening of line 4.
 * October 2006, Middle Henan Road was renamed as the.

Power supply
Siemens Transportation Systems equipped this line with an overhead contact line (cantilever material: galvanized steel) and 7 DC traction power supply substations.

Signaling
As the first part of Line 2 was opened 20 years ago and the line has been experiencing congestion after rapid ridership growth. In 2014, Shanghai Metro investigated upgrading the existing signal system of line 2 (US&S United Signal AF900, fixed block TBTC) to increase the frequency of trains and reduce congestion. In October 2020, a new CASCO Tranavi (moving block CBTC, DTO) signaling system was overlaid on the existing signaling system on Line 2. Therefore, line 2 will be the first in the world to have two signal systems, the new primary one for day-to-day operations and the existing older one serving as a backup system during signal faults. Intervals of trains on Line 2 could be reduced to 90 seconds thanks to the new signal system with the backup system capable of maintaining two minute headways. For the new system, a total of 100 trains on Line 2 will have their onboard signal systems upgraded. As of 2020 upgrading work was finished on 31 trains (the new 02A05 trains). The new signalling system was put into operation on January 27, 2024, which made it the longest signalling system renovation project in China.

Rolling stock
When line 2 was opened to traffic, the AC02 trains were not delivered. Therefore, some of the DC01 and AC01 trains were borrowed from line 1.

All are 8-car Class A rolling stock.