The following colors are used to indicate types of routes:
RED - streetcars
BLUE - trolleybuses
GREEN - CTA motor buses
BROWN - CMC bus routes
Red circles indicate CTA streetcar barns, green circles indicate CTA bus garages, and brown circles indicate CMC bus garages. In addition, Archer Ave. and North Ave. housed trolleybuses, and those and several other streetcar barns housed motor buses, as indicated by their multicolored circles.
At the time, both bus and streetcar routes were identified to the public by route number. Route numbers are not shown here due to space limitations.
Separate panels show transit routes on Chicago's north and south sides.