When the Yonge subway opened in 1954, a significant length of it was exposed to the light of day. Indeed, between the Ellis Portal (just north of Bloor station) and Berwick Avenue (just south of Eglinton station), only short stretches of tracks (a 2000-foot section between Lawton Avenue and Pleasant Boulevard around St. Clair station, and an even shorter stretch beneath the CP railway tracks near the
North Toronto railway station) were tunnelled. The portion of the line between Lawton and Berwick Avenues ran alongside Davisville Yards, a large complex which would have been expensive to put underground. The rest of the line operated along an open cut, possibly to save money on tunnelling. In fact, as construction began on the Yonge subway, plans called for the open-cut section to continue south of Bloor Street, to a point just north of Wellesley station, after which the line would dive underground in order to run beneath Yonge Street. However, in order to avoid the expropriation of several properties south of Bloor Street, the portion between Wellesley station and the Ellis Portal was put underground.
The open-cut section between Bloor and St. Clair stations gave passengers a pleasant, open-air travel experience after the featureless tunnels underground. However, as the line aged, the TTC covered over sections of the open cut between St. Clair and Summerhill stations. There were a variety of reasons this was done: to allow development to occur over the line, to reduce noise complaints from neighbouring property owners, to reduce the threat of people ending up on the subway tracks, or items being dropped in front of moving trains, and so on.