A system of express bus services operated by Pace was proposed as far back as 2014.

[2][5][6] Another express bus service was planned to run from O'Hare Airport to Evanston mostly via Dempster Street.

The Dempster Line opened on August 13, 2023, at a cost of $10 million; however, buses only ran on Sundays.

[12][13][14][15] The Milwaukee Line (internally designated as route 100) entirely runs along Pace bus route 270 from the Jefferson Park Transit Center to the Golf Mill Shopping Center.

The Dempster Line (internally designated as 101) entirely runs along Pace bus route 250 from O'Hare Multi-Modal Facility, which directly connects to O'Hare International Airport via the Airport Transit System, to a station hub on Davis Street in Evanston.