Taxis could certainly fill in some of the holes in the Red Line's service this weekend.

Flier posted by the CTA:

"Red Line Subway Trains Rerouted to Loop Elevated Tracks
11PM, Friday, September 28th until 1AM, Monday, October 1st

Due to construction work affecting the Red Line subway, Red Line trains will operate on Loop elevated tracks in both directions between the Fullerton and Cermak-Chinatown stations. Trains will make stops at Sedgwick/North, Chicago/Franklin, Merchandise Mart, Clark/Lake, State/Lake, Randolph/Wabash, Adams/Wabash, and Roosevelt/State.

Alternate shuttle bus service will operate until 1 A.M. on Monday as follows:

-Between Grand/State and Chicago/Wells Shuttle Stops: Grand (Red Line), Chicago (Red Line), and Chicago/Wells.
-Between Clark/Division and North/Clybourn Shuttle Stops: Clark/Division (Red Line), North/Sedgwick (Brown Line--entrance on Hudson), and North/Clybourn (Red Line).
-Between Roosevelt/State and Jackson/State Shuttle Stops: Adams/Wabash, Jackson/State, Harrison/State, and Roosevelt/State.

Southbound to/from Downtown: Board/exit Red Line trains at any elevated station along Lake or Wabash on Inner Loop track.
Northbound to/from Downtown: Board/exit Red Line trains at any elevated station along Wabash or Lake on Outer Loop track."