Metro systems by annual passenger rides in the context of "Beijing Subway"

The New York City Subway is a rapid transit system that serves four of the five boroughs of New York City, New York: the Bronx, Brooklyn, Manhattan, and Queens. Its operator is the New York City Transit Authority, which is itself controlled by the Metropolitan Transportation Authority of New York. In 2015, an average of 5.65 million passengers used the system daily, making it the busiest rapid transit system in the United States and the 11th busiest in the world.

The present New York City Subway system is composed of three formerly separate systems that merged in 1940: the Interborough Rapid Transit Company (IRT), the Brooklyn–Manhattan Transit Corporation (BMT), and the Independent Subway System (IND). The privately held IRT, founded in 1902, constructed and operated the first underground railway line in New York City. The opening of the first line on October 27, 1904, is commonly cited as the opening of the modern New York City Subway, although some elevated lines of the IRT and BMT that were initially incorporated into the New York City Subway system but then demolished predate this. The oldest sections of elevated lines still in operation were built in 1885. The BMT, founded in 1923 and also privately held, was formed from the bankruptcy of the Brooklyn Rapid Transit Company. The IND was created by the City of New York in 1921 to be a municipally owned competitor of the two private companies. Unification in June 1940 by the New York City Board of Transportation brought the three systems under one operator. The New York City Transit Authority, created in 1953 to be a public benefit corporation that acquired the rapid transit and surface line (buses and streetcars) infrastructure of the Board of Transportation, remains the operator of the New York City Subway today.

The Shanghai Metro (Chinese: 上海地铁; pinyin: Shànghǎi Dìtiě; Shanghainese: Zaonhe Dithiq) is a rapid transit system in Shanghai, operating urban and suburban transit services to 14 of its 16 municipal districts and to the neighboring township of Huaqiao, in Kunshan, Jiangsu Province.

Forming the vast majority of the broader, multi-operator Shanghai rail transit network, the Shanghai Metro system is the world's second longest metro system by route length, totaling 808 kilometres (502 mi) and the second largest system by number of stations, with 506 stations across 19 lines (408, if stations connected by transfers are counted as single stations). It also ranks first in the world by annual ridership, with 3.88 billion rides delivered in 2019. The last daily ridership record was set on 9 March 2024, at 13.39 million rides. Ridership routinely stands at over 10 million on an average workday, accounting for 73% of trips on public transport in the city.