Public transportation in Milwaukee in 1938, the year the company was reorganized and The Milwaukee Electric Railway & Transport Co. was formed. Streetcar routes are orange, trolleybus routes are blue, and motor bus routes are brown. Light green indicates the "Green Bus" routes, operated independently from the other bus routes which started as extensions of the streetcar system.

In addition, various interurban lines radiated out of Milwaukee in various directions. Thicker lines indicate interurban trackage on private right of way, including the "Rapid Transit" line, opened west of downtown Milwaukee in 1930.

Trackage of the Chicago North Shore & Milwaukee Railroad is shown in green. Local streetcar service was provided on 6th Street until 1951. Thicker line indicates private interurban right of way, mostly on an embankment.

Route numbers are shown in parentheses, with most route numbers still in use by today's bus routes.