Inside the Collection is a video series that invites you into the Chicago History Museum’s storage spaces to explore unusual, interesting artifacts from our vast collection.

In this installment, senior collection manager Britta Keller Arendt and summer intern Amy Sparks discuss an original traffic controller switch, c. 1926, from Chicago’s Loop. The city used this switch and others like it to automate traffic lights in the central business district from a control center in the basement of city hall. On the switch, you may notice that the Municipal Device symbol—an encircled Y to symbolize the three branches of the Chicago River—is upside down. Some city officials employed this variation after the Metropolitan Sanitary District of Greater Chicago reversed the flow of the Main Stem and South Branch in 1900.

Explore our collection.