The TTC operates one of the most extensive urban mass transit systems in North America, but specifically we're talking about the subway here. 560,000 people use the Toronto Subway on the average weekday, 880,000 if you count transfers from streetcars, buses, etc. Overall if you count the whole system including buses, subways, etc, the TTC carries 420 million a year which is 3rd in North America to only New York and Mexico City. There is 70 km of subway track, and 74 stations. The Subway operates every 2-3 minutes during rush hours and every 5 minutes the rest of the day and on weekends, the Scarborough RT runs every 3-5 minutes during rush hours and every 5-6 minutes daytime and weekends. The Sheppard Subway runs every 5-6 minutes all times. The subway system itself is a pretty basic get the job done system. The stations arent flashy, the trains arent flashy but it is highly efficient and very well run, arguably the best run in North America.
Subway, RT map.
Aswell as im sure many of you know Toronto has streetcars to serve lighter routes, and feed the subway
Map of subway and streetcars.