Editing Rail transport (section)

===Metros===
{{Main|Rapid transit}}
[[File:R160 E enters 42nd Street.jpg|thumb|The [[New York City Subway]] is the world's largest single-operator rapid transit system by number of [[metro station|stations]].]]
[[File:M4 San Babila appena inaugurata.jpg|thumb|[[Milan Metro]] is the largest rapid transit system in Italy in terms of length, number of stations and ridership; and the eighth longest in [[Europe]].<ref>{{cite web|url=https://www.milanocittastato.it/trasporti/effetto-m4-la-metro-di-milano-entra-nella-top-europea/?fbclid=IwY2xjawF3U1dleHRuA2FlbQIxMQABHXSpIbaPnyiu6v7H7zI_mDyWgUrPadrCjN6GDzfUhPP2dI-Mfj4jLYBecw_aem__7hUFLg35ygwuZipXbL1Vg#goog_rewarded|title=Effetto M4: la metro di Milano entra nella top europea|date=11 October 2024 |access-date=12 October 2024|language=it}}</ref>]]

[[Rapid transit]] or mass rapid transit (MRT) or heavy rail,<ref name="EnBr">{{cite web |title=Mass transit - Urban Mobility, Efficiency, Environment |url=https://www.britannica.com/topic/mass-transit/The-benefits-of-urban-mass-transit |website=Britannica |access-date=29 September 2024 |language=en |date=4 September 2024}}</ref><ref name="APTA">{{cite web |title=Fact Book Glossary |url=https://www.apta.com/research-technical-resources/transit-statistics/public-transportation-fact-book/fact-book-glossary/ |website=American Public Transportation Association |access-date=29 September 2024}}</ref> commonly referred to as metro, is a type of high-capacity [[public transport]] that is generally built in [[urban area]]s. A [[grade separation|grade separated]] rapid transit line below ground surface through a [[tunnel]] can be regionally called a subway, tube, metro or underground.<ref name="miriamwebster">{{cite web|url=http://www.merriam-webster.com/dictionary/rapid%20transit|title=Rapid transit|publisher=[[Merriam-Webster]]|access-date=2013-07-31|archive-url=https://web.archive.org/web/20130720025558/http://www.merriam-webster.com/dictionary/rapid%20transit|archive-date=2013-07-20|url-status=live}}</ref><ref name="IUTPMetro">{{cite web|url=http://ftp.uitfp.org/ftproot/euroteam/YVA/URP_Fundamental_Requirements_EN.pdf|title=Recommended basic reference for developing a minimum set of standards for voluntary use in the field of urban rail, according to mandate M/486|author=UITP|year=2011|access-date=2014-02-16|archive-url= https://web.archive.org/web/20140222133945/http://ftp.uitp.org/ftproot/euroteam/YVA/URP_Fundamental_Requirements_EN.pdf|archive-date=2014-02-22|url-status=usurped}}</ref><ref name=aptaglossary>{{cite web|url=http://www.apta.com/resources/reportsandpublications/Documents/Transit_Glossary_1994.pdf|title=Glossary of Transit Terminology|publisher=[[American Public Transportation Association]]|access-date=2013-07-31|archive-url=https://web.archive.org/web/20130512230056/http://www.apta.com/resources/reportsandpublications/Documents/Transit_Glossary_1994.pdf|archive-date=2013-05-12|url-status=live}}</ref><ref name="mrt">{{cite journal |title=Mass rapid transit systems for cities in the developing world |year=2003 |url=https://www.tandfonline.com/doi/pdf/10.1080/0144164032000083095 |publisher=Taylor & Francis Online |doi=10.1080/0144164032000083095 |access-date=2 April 2023 |last1=Fouracre |first1=Phil |last2=Dunkerley |first2=Christian |last3=Gardner |first3=Geoff |journal=Transport Reviews |volume=23 |issue=3 |pages=299–310 |s2cid=154931412 |url-access=subscription }}</ref> They are sometimes grade-separated on [[elevated railway]]s, in which case some are referred to as el trains – short for "elevated" – or skytrains. Rapid transit systems are usually [[electric railway|electric]] [[railway]]s, that unlike [[bus]]es or [[tram]]s operate on an exclusive [[right-of-way (transportation)|right-of-way]], which cannot be accessed by pedestrians or other vehicles.<ref name="Britannica">{{cite web|url=http://www.britannica.com/EBchecked/topic/491506/rapid-transit|title=Rapid Transit|publisher=[[Encyclopædia Britannica]]|access-date=2014-11-28|archive-url=https://web.archive.org/web/20141017033402/http://www.britannica.com/EBchecked/topic/491506/rapid-transit|archive-date=2014-10-17|url-status=live}}</ref>

Modern services on rapid transit systems are provided on designated lines between [[metro station|stations]] typically using [[electric multiple unit]]s on [[railway track]]s. Some systems use [[rubber-tyred metro|guided rubber tires]], magnetic levitation (''[[maglev]]''), or [[monorail]]. The stations typically have high platforms, without steps inside the trains, requiring custom-made trains in order to minimize gaps between train and platform. They are typically integrated with other public transport and often operated by the same [[transit authority|public transport authorities]]. Some rapid transit systems have at-grade intersections between a rapid transit line and a road or between two rapid transit lines.<ref name="UrbanRail.net">{{cite web|url=http://www.urbanrail.net/am/chic/chicago.htm|title=Chicago|access-date=2015-04-24|archive-url=https://web.archive.org/web/20150416074705/http://www.urbanrail.net/am/chic/chicago.htm|archive-date=2015-04-16|url-status=live}}</ref>

The world's first rapid transit system was the partially underground [[Metropolitan Railway]] which opened in 1863 using [[steam locomotive]]s, and now forms part of the [[London Underground]].<ref name=150Anniv>{{Cite book |url=http://www.tfl.gov.uk/corporate/modesoftransport/londonunderground/1604.aspx |title=London Underground: History|author=Transport for London |isbn=978-0-904711-30-1 |access-date=2013-01-02 |archive-url=https://web.archive.org/web/20130116190701/http://www.tfl.gov.uk/corporate/modesoftransport/londonunderground/1604.aspx |archive-date=2013-01-16 |url-status=dead|year=1981|publisher=Capital Transport }}</ref> In 1868, New York opened the elevated [[IRT Ninth Avenue Line|West Side and Yonkers Patent Railway]], initially a cable-hauled line using [[stationary steam engine]]s.

{{As of|2021}}, [[China]] has the largest number of [[List of metro systems|rapid transit systems in the world]]{{snd}}40 in number,<ref>{{Cite web|date=2021-03-29|title=Luoyang and Ji'nan open metro lines|url=https://www.railjournal.com/regions/asia/luoyang-and-jinan-open-metro-lines/|access-date=2021-06-07|website=International Railway Journal|language=en}}</ref> running on over {{convert|4,500|km|abbr=on}} of track{{snd}}and was responsible for most of the world's rapid-transit expansion in the 2010s.<ref>{{Cite news|url=https://www.itdp.org/2018/07/30/china-drives-rapid-transit-growth/|title=China's Metro Boom Continues to Drive Rapid Transit Growth – Institute for Transportation and Development Policy|date=2018-07-30|work=Institute for Transportation and Development Policy|access-date=2018-11-20|language=en-US|archive-url=https://web.archive.org/web/20181120095357/https://www.itdp.org/2018/07/30/china-drives-rapid-transit-growth/|archive-date=2018-11-20|url-status=live}}</ref><ref>{{Cite web|title = Metro Data|url = http://metro-data.info/|website = metro-data.info|access-date = 2018-09-28|archive-url = https://web.archive.org/web/20180929000328/http://metro-data.info/|archive-date = 2018-09-29|url-status = usurped}}</ref><ref>{{Cite news|url=https://www.itdp.org/2017/02/17/rapid-transit-trends/|title=Rapid Transit Trends Show Record Growth in 2016, with Huge Increases in China, Brazil – Institute for Transportation and Development Policy|date=2017-02-17|work=Institute for Transportation and Development Policy|access-date=2018-11-20|language=en-US|archive-url=https://web.archive.org/web/20181023020236/https://www.itdp.org/2017/02/17/rapid-transit-trends/|archive-date=2018-10-23|url-status=live}}</ref> The world's longest single-operator rapid transit system by [[Network length (transport)|route length]] is the [[Shanghai Metro]].<ref>{{cite magazine|url=http://www.railwaygazette.com/news/single-view/view/10/shanghai-now-the-worlds-longest-metro.html|title=Shanghai now the world's longest metro|magazine=[[Railway Gazette International]]|date=4 May 2010|access-date=2010-05-04|archive-url=https://web.archive.org/web/20100515130655/http://www.railwaygazette.com/news/single-view/view/10/shanghai-now-the-worlds-longest-metro.html|archive-date=15 May 2010|url-status=live}}</ref><ref>{{cite news |last=Smith |first=Stephen J. |url=http://nextcity.org/daily/entry/new-starts-shanghai-metro-worlds-longest-panama-canal-drama-japans-maglev |title=New Starts: Shanghai Metro World's Longest, Panama Canal Drama, Japan's Maglev |newspaper=Next City |date=6 January 2014 |access-date=2014-09-21 |archive-url=https://web.archive.org/web/20140925160200/http://nextcity.org/daily/entry/new-starts-shanghai-metro-worlds-longest-panama-canal-drama-japans-maglev |archive-date=25 September 2014 |url-status=live }}</ref> The world's largest single rapid transit service provider by number of stations (472 stations in total)<ref>{{cite web |url=http://web.mta.info/nyct/facts/ridership/ |title=Facts – Subway and Bus Ridership |publisher=[[Metropolitan Transportation Authority|Metropolitan Transportation Authority (MTA)]] |access-date=2014-09-21 |archive-url=https://web.archive.org/web/20140912073839/http://web.mta.info/nyct/facts/ridership/ |archive-date=2014-09-12 |url-status=live }}</ref> is the [[New York City Subway]]. The [[List of metro systems|busiest rapid transit systems in the world]] by annual ridership are the Shanghai Metro, [[Tokyo subway|Tokyo subway system]], [[Seoul Metro]] and the [[Moscow Metro]].