504 King

The 504 King is a streetcar route operated by the Toronto Transit Commission in Toronto, Ontario, Canada. It is grouped together with the 508 Lake Shore for accounting purposes. In 2005-2006, these routes carried 47,900 passengers on an average weekday (of which the vast majority were carried by 504 King), making 504 King the busiest TTC streetcar route in terms of number of passengers. The route operates seven days a week, 24 hours a day. During weekday rush hours, day time and early evenings, average service frequency is 4 minutes or less. Saturday daytime services have an average frequency of 4–5 minutes with Sunday daytime service frequency averaging 6–7 minutes.

The route provide primary service along King Street in Toronto's downtown core. 504 cars provide additional service to the 508 route along Roncesvalles Avenue and Broadview Avenue. Both lines interchange mid-route with the Yonge-University-Spadina line at St. Andrew and King stations. The 504 King interchanges with the Bloor-Danforth line at its termini, Dundas West and Broadview stations, which the route shares with 505 Dundas streetcars.

The lines are usually operated with Toronto's single-length CLRV streetcars. In 2006 the TTC briefly considered adding couplers to its streetcars in order to run the King route with trains of two or three units, as was common on busy routes until the opening of the Bloor-Danforth subway; the hope was that this would keep them from bunching and becoming stuck in traffic. The plan was rejected.

During rush hour periods, 504 King is operated by ALRVs in addition to the regular CLRVs.