The Electroliner is on the North Side Mainline over Franklin St. Depending on the date, those tracks were owned by the CTA based on the buildings, cars & streetlight poles. Sometime in the 1950s
It’s not used by the Red Line [except in emergencies, called “going over the top”], but by the Brown & Purple Lines.
The North Shore Line leased trackage rights into Chicago from Dempster St. in Skokie south to Roosevelt. From Dempster north to Milwaukee was owned by the CNS&M, except for the end in Milwaukee which was on the street, like a streetcar, which the original Shoreline Route also took through Wilmette from the end of the L at 4th & Linden on 4th & on Greenleaf.