Streetcar service on Bathurst Street started on July 27, 1885, when the Toronto Street Railway opened a horsecar line between Bloor Street and College Street. The line was extended to King Street in December 1889, and to Front Street on September 5, 1892. The Toronto Railway Company electrified the line on April 19, 1894, and extended it north to Dupont Street on July 10, 1894. The railway corridor south of Front Street remained a barrier until August 25, 1916, when a bridge was constructed at a southwest angle over the railway tracks. South of the rail corridor, streetcars ran along the edge of Fort York to provide seasonal service to Exhibition Place. On December 21, 1921, the Toronto Transportation Commission extended the line to St. Clair Avenue. In 1931, the bridge over the railway corridor south of Front Street was realigned in a north–south alignment. On June 22, 1931, streetcar service started on Fleet Street, which became part of the "Fort" route. Just prior to the opening of Line 2 Bloor–Danforth on February 25, 1966, Bathurst Street was served by two streetcar routes, Fort and Bathurst. The Fort route ran from Vaughan Loop to Exhibition Loop. The Bathurst route ran south from Vaughan Loop to Adelaide Street turning east on that street, then south on Church Street, west on King Street to return north on Bathurst Street. However, before the city converted Adelaide Street to a one-way, eastbound street in 1960, Bathurst streetcars would loop downtown north from Adelaide Street on Church Street, west on Richmond Street, south on York Street to return westbound on Adelaide Street. With the Line 2 Bloor–Danforth opening, service north of Bloor Street to Vaughan Loop was discontinued, with cars terminating at the then-new Bathurst station. Service north of Bloor was replaced with the 7 Bathurst bus, although the tracks there remain today for non-revenue use to connect the St. Clair streetcar line and the Hillcrest Complex to the rest of the streetcar network. Bathurst streetcar service along Adelaide Street was also terminated, with the tracks being ultimately abandoned with the exception of one track between Victoria and Church streets. The Fort and Bathurst routes were merged, and the "Fort" name was discontinued. With these changes, the Bathurst route resembled today's 511 Bathurst. In June 1995, the old Exhibition Loop at the site of today's Trade Centre was closed, and a new loop was opened next to Exhibition GO station on June 16, 1996. On July 21, 2000, the 509 Harbourfront route shared tracks with 511 Bathurst from Bathurst Street west to Exhibition Loop. Between September 2007 and March 2008, the tracks along Fleet Street were rebuilt in a private right-of-way. Also, during this time, the overhead wire was rebuilt to allow for subsequent pantograph operation along Fleet Street, the first location to be so equipped. Starting in 2015, the TTC introduced summer service using Flexity Outlook streetcars to handle events such as the 2015 Pan American Games at the "CIBC Pan Am / Parapan Am Park" and the Canadian National Exhibition. Due to a streetcar shortage caused by late delivery of the Bombardier Flexity Outlook streetcars, the route was operated using buses rather than streetcars since November 20, 2016. TTC streetcar service on 511 Bathurst returned from May 7, 2017, until September 4, 2017, when the 511 Bathurst route reverted to replacement bus service due to an ongoing streetcar shortage. On February 18, 2018, streetcars returned to the route, followed by another period of bus replacement that began on September 2, 2018. On June 23, 2019, streetcars returned to 511 Bathurst, ending the temporary replacement bus service. It operated using a mixture of both CLRVs and Flexities until December 28, 2019, the last day for CLRVs on this route. The 511 Bathurst route was the last route in Toronto to run CLRVs seven days per week. Replacement bus service was reinstated again on April 20, 2020, due to various construction projects. For a short time from June 21 to July 27, 2020, the 511 Bathurst route was rerouted to Spadina station via Harbord Street and Spadina Avenue due to road construction along Bathurst street between Harbord and Dupont streets.
