Chicago 'L' Transit Network

Day 26 (Transport): I created a stylized map of Chicago’s iconic ‘L’ transit network, showcasing the city’s comprehensive public rail system against a dark urban backdrop. This visualization highlights seven CTA (Chicago Transit Authority) rail lines—Red, Blue, Brown, Green, Orange, Purple, and Pink—each rendered in their official brand colors. The map layers transit routes over major highways (Interstates, US, and State routes) and water features, providing geographic context while emphasizing the transit network’s extensive coverage throughout the city. The dark theme creates a striking visual effect that makes the colored transit lines pop, reminiscent of subway maps and urban transit diagrams.

Technical Implementation:

• sf (Simple Features) - R package for handling spatial vector data and geometric operations, including coordinate transformations and spatial intersections
• tigris - R package for downloading TIGER/Line shapefiles from the US Census Bureau, providing access to city boundaries, roads, and water features
• tidyverse - Collection of R packages for data manipulation and visualization, including ggplot2 for map creation and dplyr/stringr for data wrangling
• ggplot2 - R’s powerful data visualization package, used with geom_sf() for creating the layered map visualization with custom color scales

Data Sources:

• CTA Rail Lines: Chicago Transit Authority Rail Lines Shapefile - Official shapefile containing the geometry and attributes of Chicago’s ‘L’ transit system rail lines
• City Boundary: U.S. Census Bureau TIGER/Line Shapefiles 2023 - Chicago city boundary from Illinois places via tigris package
• Roads: U.S. Census Bureau TIGER/Line Shapefiles - Cook County road network filtered to major routes (Interstates, US Routes, State Routes)
• Water Features: U.S. Census Bureau TIGER/Line Shapefiles - Cook County area water features (lakes, rivers)