TTC Transit Flow: Visualizing Toronto’s Subway and Streetcar Network

Toronto’s public transit system, which is operated by the Toronto Transit Commission (TTC) is one of the most extensive in North America, carrying over 1.6 million passengers daily. The video, and map below highlights the flow of Toronto’s subway and streetcar lines, demonstrating the lifelines that keep the city moving every day.

About the Map

This interactive visualization displays the TTC’s subway and streetcar network using OpenStreetMap data. Each line is color-coded to represent the mode of transit:

• Cyan (Blue) → Subway Lines

• Orange → Streetcar Routes

  
  

The basemap uses a dark theme to enhance contrast, allowing the vibrant transit lines to stand out against Toronto’s urban layout. Major hubs such as Union Station, Bloor-Yonge, St. George, and Kennedy emerge as dense intersections of mobility where commuters transfer between subway lines or to surface routes.

Data and Method

The map was built using:

• OpenStreetMap (OSM) for transit geometries and routes

• Leaflet and CARTO basemap for interactive visualization

• Python tools such as osmnx, geopandas, and folium for data processing and rendering

  
  

Each route was extracted, styled, and exported as an HTML map that can be explored directly in a browser. The visualization intends to show the spatial coverage and connectivity of TTC’s core network, from Vaughan in the north to The Beaches and Scarborough in the east, and Kipling and Long Branch in the west.

Reading the Flow

Toronto’s transit structure forms a north-south and east-west spine:

• Subway lines serve as the high-capacity backbone, connecting distant suburbs to the downtown core.

• Streetcars, unique to Toronto among North American cities, provide dense local coverage, especially in older urban neighbor hoods such as Queen Street, King Street, and St. Clair Avenue.

  
  

The interplay between these two systems defines Toronto’s urban rhythm with subways moving people quickly across long distances, while streetcars fill in the gaps with fine-grained local accessibility.

Why This Matters

Understanding transit flow helps urban planners, geographers, and data scientists visualize:

• Mobility corridors and potential bottlenecks

• Transit accessibility in underserved neighborhoods

• Urban growth patterns shaped by transit availability

This type of mapping also bridges design and data blending aesthetics with public information to reveal how cities breathe and move.

Future Work

Future versions of this project could incorporate:

• GTFS (General Transit Feed Specification) data for real-time vehicle locations

• Ridership density visualization to highlight peak-hour congestion

• Accessibility and coverage analysis using network algorithms in Python

  
  

These extensions would transform this static network map into a dynamic transit analytics tool, supporting smarter mobility decisions and more equitable city planning.

Author: Zarrin Tasneem

Tools: Python (osmnx, geopandas, folium), Leaflet, CARTO

Project: TTC Transit Flow Map — Toronto’s Moving Network