No elevated trains will run in the Loop from 4 a.m. Saturday through 2 a.m. Monday due to track maintenance.

Geoffrey Baer tackles three questions about Chicago's beloved rapid transit system, including the various spellings of the system, in this encore edition of Ask Geoffrey.

Geoffrey Baer tackles three questions about Chicago's beloved rapid transit system, including the various spellings of the system, old downtown entrances between elevated stations and Loop stores and a mysterious tunnel a viewer spotted while riding the Blue Line.