In 1958 there were already plans for an ‘L’ line on the median of the Northwest (Kennedy) Expressway. To serve the Montrose Avenue station, CTA now proposed constructing a massive Park ‘N’ Ride garage—built on air-rights over the junction with the Edens Expressway! The view is looking south, with Wilson Avenue running horizontally across the bottom, and Cicero Avenue moving vertically on the right. The garage was never built.
—30—
Chicago History Today 
Note the heliport on top! How many people did the CTA think wanted to connect to the ‘L’ via helicopter?
When CTA inaugurated ‘L’ service on the Kennedy median in 1970, the trains went only as far as Jefferson Park—the line wasn’t extended to O’Hare until 1984. During those years, extension buses (Route #19) connected the trains at Jefferson Park with O’Hare. So maybe CTA initially planned on having extension helicopters instead of extension buses!
–JRS
I thought the O’Hare Express route was #40.
When the Northwest (Kennedy) Expressway opened, CTA inaugurated rush-hour-only Route #19–Devon-Northwest Expressway. Buses left the Logan Square ‘L’ terminal, then ran express via Logan-California-NW Expressway. Depending on whether it was A.M. or P.M. rush hour, the buses followed different routes beyond Foster-Central. The outer terminal was Northwest Highway-Ozark. Later, when CTA extended ‘L’ service to Jefferson Park, the #19 route designation was retained for awhile on the O’Hare Express route, before the change was made to #40. I probably shouldn’t have mentioned the route-number in the first place!
–JRS