Other than the Through Routes, the first vehicles with signs displaying route numbers were trolleybuses, introduced in 1930. Motor buses began displaying route numbers in 1935. PCC streetcars displayed route numbers upon their introduction in 1936, while signs with route numbers were installed on older streetcars after the CTA takeover in 1947.
Most routes listed survive today as CTA bus routes. Also listed are most of the discontinued bus and streetcar routes. Most route histories are included under the present routes. Although for simplicity, route histories of portions of certain routes are instead listed under the discontinued routes.
The Through Routes are listed first. Through Routes still in existence are also listed with the various local routes.
Through Routes 1-23
Former Chicago Motor Coach Routes
Listed for each route are dates of first horse car, first cable car, first electric streetcar, and first bus service. Although the introduction of cable cars or electric streetcars on a route, did not necessarily mean the immediate total elimination of older horse cars or cable cars on all segments of that route.
Also indicated are the private companies introducing those routes created before the formation of CTA. Chicago Surface Lines actually consisted of several companies all working together, forming a unified streetcar and bus system. In addition, many routes were originally introduced by the Chicago Motor Coach Co.
Omitted are certain temporary, experimental or seasonal routes. Also omitted are certain minor route changes and extensions, especially changes in downtown routings. Many routes were gradually extended in stages, before reaching the maximum length.
Not included are specific hours of operation for the routes. Most routes created as streetcar routes had "owl" service, or operated 24 hours a day. Most routes created as bus routes never had owl service. Owl service is mentioned, although dates of introduction are not available. Much of the owl service was eventually scaled back or discontinued. Not mentioned are situations where only a portion of a route has owl service, or where hours of service are different for different portions of a route. All routes have generally operated at least throughout the daytime, 7 days a week, unless noted.
Included are the primary car houses or bus garages for the routes. Although for many routes, primarily during rush hours, certain runs operated out of other car houses or bus garages.
In 1973, CTA began operating four bus routes in Evanston, after the Evanston Bus Company ceased operations, and CTA was the only agency suited to operate such a service. Routes are numbered in the low 200's.
CTA Route Numbering System
Route numbers became widely used by CTA during the 1950's.