Editing Line 1 Yonge–University (section)

===Operations and extensions from 1954 to 2017===
Trains operated at average speeds of {{Convert|20|mph|km/h|order=flip}}.<ref name="TheStar-1954-03-30">"Traffic authorities from all over world see subway opened", ''Toronto Daily Star'', March 30, 1954, p. 3.</ref> The plan to operate two-car trains during off-peak hours was abandoned in favour of four-car trains, and six-car trains were standard during most periods, with some eight-car trains used during peak periods.{{cn|date=May 2023}}

On February 28, 1963, an extension was added to curve north from Union Station, below [[University Avenue (Toronto)|University Avenue]] and [[Queen's Park (Toronto)|Queen's Park]] to near [[Bloor Street]], where it turned west to terminate at [[St. George station|St. George and Bloor Street]].<ref name="TTC-2013-Stats">{{cite web |url=http://ttc.ca/About_the_TTC/Operating_Statistics/2013.jsp |title=2013 TTC Operating Statistics |publisher=[[Toronto Transit Commission]] |access-date=January 27, 2017 |archive-date=July 25, 2021 |archive-url=https://web.archive.org/web/20210725092951/https://www.ttc.ca/About_the_TTC/Operating_Statistics/2013.jsp |url-status=dead }}</ref>

On February 26, 1966, the [[Line 2 Bloor–Danforth|Bloor–Danforth line]] opened, from [[Keele station|Keele]] to [[Woodbine station|Woodbine]]. For six months, as a trial, the Yonge–University line operated as two branches, Eglinton–Keele, and Eglinton–Woodbine. The interline was determined not worthy, and the Yonge–University line was cut back to St. George on September 4, 1966.<ref name=":1" />

[[File:TTCSubwaySign.jpg|thumb|Original-style subway entrance sign in [[Downtown Toronto]] in 2008]]
On June 23, 1969, the University subway service from St. George to Union stations was discontinued entirely after 9:45&nbsp;p.m. from Mondays to Saturdays and all day on Sundays and holidays. The 5B Avenue Road buses run in place between Eglinton and Front Street whenever the University subway did not operate, with side-jaunts to St. George station to capture passengers from the Bloor subway. This arrangement remained in place until January 28, 1978, when the Spadina subway opened north to Wilson Station.<ref name=":1">{{Cite web|url=http://transittoronto.ca/subway/5103.shtml|title=The University Subway – Transit Toronto – Content|access-date=March 15, 2020|archive-date=October 13, 2020|archive-url=https://web.archive.org/web/20201013130130/https://transittoronto.ca/subway/5103.shtml|url-status=live}}</ref>

On March 31, 1973, the line was extended north from {{stl|TTC|Eglinton}} to {{stl|TTC|York Mills}},<ref name="TTC-2013-Stats" /><ref>{{cite news |title=Yonge Subway Extension to York Mills |work=The Globe and Mail |location=Toronto |date=March 27, 1973 |volume=130 |issue=38,470 |page=13}}</ref> and on March 29, 1974, to {{stl|TTC|Finch}}.<ref name="TTC-2013-Stats" /> These two extensions were part of the North Yonge Extension project, bringing the subway to North York.{{cn|date=May 2023|reason=Needs a citation for the name "North Yonge Extension Project"}}

Stations were also planned for Glencairn (between Eglinton and Lawrence, though another [[Glencairn station]] would be built later on the Spadina section), Glen Echo (between Lawrence and York Mills) and Empress (between Sheppard and Finch, later opened as [[North York Centre station]]).{{cn|date=May 2023}}

On January 27, 1978, the Spadina segment of the line was opened, going from St. George station, the north terminus of the University line, to [[Wilson station (Toronto)|Wilson station]].<ref name="TTC-2013-Stats" /> From St. George station, the {{Convert|9.9|km|mi|1|abbr=on}} segment ran north and northwest to Eglinton Avenue and [[Allen Road|William R. Allen Road]], then north along the median of the Allen Road to Wilson Avenue. This extension had been proposed as part of the [[Spadina Expressway]], but when the expressway portion south of Eglinton Avenue was [[Highway revolt#Toronto|cancelled after massive protests]], the subway was still built following the route through [[Castle Frank Brook|Cedarvale Ravine]]. Hence, it was called the Spadina line, though it follows [[Spadina Avenue|Spadina Road]] for less than {{Convert|2|km|mi|1|abbr=on}}.{{cn|date=May 2023}}

On June 18, 1987, North York Centre station was added between Sheppard and Finch stations as an infill station to serve the rapidly growing North York City Centre.<ref name="TTC-2013-Stats" />

On August 11, 1995, at 6:02&nbsp;pm, the [[1995 Russell Hill subway accident|Russell Hill subway accident]] occurred as a southbound subway train heading toward [[Dupont station]] crashed under Russell Hill Drive, killing three passengers and sending 30 to hospital.<ref>{{cite news |last=Hall |first=Joseph |url=http://transittoronto.ca/archives/data/200508061136.shtml |newspaper=Toronto Star |title=Ten Years After |date=August 6, 2005 |access-date=February 17, 2012 |archive-date=May 31, 2020 |archive-url=https://web.archive.org/web/20200531044841/https://transittoronto.ca/archives/data/200508061136.shtml |url-status=live }}</ref> This accident prompted the Toronto Transit Commission to review its practices and put resources into safety.{{cn|date=May 2023}}

On March 31, 1996, the Spadina segment of the line was extended {{Convert|2|km|mi|1|abbr=on}} from Wilson station north to Downsview station (renamed {{stl|TTC|Sheppard West}} in 2017).<ref name="TTC-2013-Stats" />  
[[File:Finch West 2016.JPG|thumb|right|[[Finch West station]] on the [[Toronto–York Spadina subway extension|TYSSE]] under construction in 2016]] 
On November 17, 2016, with the [[Presto card|Presto]] fare gates installed at Eglinton station, all of the stations along the line became Presto-enabled.<ref>{{cite tweet |user=PRESTOcard |number=799287911317381120 |date=November 17, 2016 |title=Eglinton subway station has brand new PRESTO fare gates! All of @TTChelps Line 1 is now PRESTO enabled. #spotPRESTO}}</ref>

On December 17, 2017, the western portion of the line was extended {{Convert|8.6|km|mi|abbr=|adj=}} north to [[Vaughan Metropolitan Centre station]] in [[Regional Municipality of York|York Region]], via [[York University]].<ref>{{Cite web |date=December 15, 2017 |title=Justin Trudeau joins premier, mayor at TTC line 1 extension opening |url=https://www.cbc.ca/news/canada/toronto/trudeau-subway-extension-1.4450237 |access-date=September 16, 2023 |website=CBC News}}</ref> The [[Toronto–York Spadina subway extension]] (TYSSE) project built six new stations at a cost of $3.2 billion, with {{Convert|6.2|km|mi|abbr=out}} in Toronto and {{Convert|2.4|km|mi|abbr=out}} in York Region. The TYSSE was the first new section of a subway line to be opened since the opening of [[Line 4 Sheppard]] in 2002.<ref name="G&M-2017-12-14">{{cite news |last1=Moore |first1=Oliver |last2=Gray |first2=Jeff |date=December 14, 2017 |title=Next stop, Vaughan: Inside the Toronto subway's big move beyond the city limits |url=https://www.theglobeandmail.com/news/toronto/toronto-subway-extension/article37324030/ |url-status=live |archive-url=https://web.archive.org/web/20171215035217/https://www.theglobeandmail.com/news/toronto/toronto-subway-extension/article37324030/ |archive-date=December 15, 2017 |access-date=December 15, 2017 |newspaper=[[The Globe and Mail]]}}</ref> In the year after the extension opened, most stations on the extension saw below average ridership compared to the rest of the subway system.<ref name="ts121618">{{cite news |last1=Spurr |first1=Ben |title=Two stations on new York subway extension among the least used on the TTC network |url=https://www.thestar.com/news/gta/two-stations-on-new-york-subway-extension-among-the-least-used-on-the-ttc-network/article_ce2e593a-21dc-548a-ba64-2ea4e412c310.html |access-date=November 21, 2024 |work=Toronto Star |date=December 16, 2018}}</ref>