The Toronto Transit Commission (TTC) operates North America's third-largest public transit system, providing subway, streetcar, and bus service across Toronto. The TTC carries over 500 million riders annually across four subway lines, extensive surface routes, and the world's largest streetcar network. As a municipal agency, the TTC is funded through fares, City of Toronto property taxes, and provincial/federal grants. Subway expansion projects have required substantial provincial and federal investment. The TTC demonstrates scale and complexity of transit in Canada's largest city, facing challenges including aging infrastructure, capacity constraints, fare integration with regional services, and balancing accessibility with operational efficiency.