It was intended to demonstrate the latest technologies to operating agencies and the riding public, and serve to promote existing and proposed transit lines.

The new cars were to represent the state of the art in transit vehicle technology; priority was placed on making them comfortable, safe, reliable, and quiet to attract passengers.

[2] The SOAC was built to meet the loading gauge of existing rapid transit systems in Boston, Chicago, Cleveland, New York City, and Philadelphia.

[7] It was restricted to certain lines, including the B Division in New York City and the Skokie Swift in Chicago because other parts of those systems had smaller loading gauges.

The cars were slightly wider and substantially longer than other CTA rolling stock; the platforms at the two Skokie Swift stations were modified with retractable edges.

[7] The next stop was Philadelphia, where the SOAC operated on revenue service on the SEPTA Broad Street Line from March 6 to April 2, 1975.

[7][14] The SOAC cars were stored at Boeing Vertol until May 1979, when one was shipped to the Budd Company and one to Pueblo, where they were used for additional subsystem testing.

[7][3] The two-car demonstrator was acquired by the Seashore Trolley Museum in Kennebunkport, Maine as a static display in 1989 and has remained there since.