The CTA's Blue Line connects O'Hare International Airport with Chicago's loop and West Side. This line runs through both subways, elevated tracks, and at ground level.

The O'Hare and Forest Park (formerly Congress) branches run 24 hours a day, 7 days a week. The 54th-Cermack (formerly Douglas) branch, however, only runs between 4:00 am and midnight on weekdays, with no overnight or weekend/holiday service. Passengers who are travelling during times when the Douglas branch is out of service should either use trains to Forest Park, or take the bus.

There is a project underway to renovate the Douglas branch of the Blue Line (called Renew the Blue). As such, stations may be closed for renovation. Though track work is only done at times when the branch is not in service, passengers may still experience delays. Call 836-7000 (from any local area code) for travel information, or 1-888-YOUR-CTA for customer service information.

Below is a text map of the Blue Line's route. Please keep in mind that it is not to scale. Traffic is two-way in all areas of the map. Sections of the Blue line that are subway are indicated by ·, and non-subway portions use - or | to indicate the route. North is up. Stations are marked with either an o or a (T). The latter represents a free transfer station. Mouse-over the (T) to see which lines you can transfer to at that station.

      C
      U
   R  M
   O  B
   S  E  H
O  E  R  A
H  M  L  R
A  O  A  L
R  N  N  E
E  T  D  M

o·-o--o--o-
           \
            o JEFFERSON PARK
             \
              o MONTROSE
               \
                o IRVING PARK
                 \
O'Hare            o ADDISON
  Branch           ·
                    o BELMONT
                    ·
                    o LOGAN SQUARE
                     ·
                      o CALIFORNIA
                       \
                        o WESTERN
                         \
                          o DAMEN
                           ·
                            o DIVISION   C
                    K        ·           L
                    E         o CHICAGO  A
                    D          ·         R
F                   Z           o GRAND  K
O                   I            ·       
R               P   E   W   M     ······(T)-+
E  H  O  A  C   U   \   E   E * R***********·*****
S  A  A  U  I   L   H   S   D * A        * (T)WASHINGTON  L
T  R  K  S  C   A   O   T     * C        *  ·    *        o
   L     T  E   S   M   E   C * I        *  o MONROE      o
P  E  P  I  R   K   A   R   T * N        *  ·    *        p
K  M  K  N  O   I   N   N   R * E        * (T)JACKSON
                              *          ***·***** 
o--o--o--o--o---o---o---o---o-+-o--o-·o··o··+
Forest Park/Congress Branch  /
                        POLK o     U  C  L
                             |     I  L  A
54th/Cermak             18th o     C  I  S
Douglas   o-o-o-o-o-o-o-o-o-/      /  N  A
Branch                             H  T  L
          5 C K P C K C W H        A  O  L
          4 I I U E E A E O        L  N  E
          / C L L N D L S Y        S      
          C E D A T Z I T N        T      
          E R A S R I F E E        E      
          R O R K A E O R          D
          M   E I L   R N          
          A           N            
          K       P   I            
                  K   A            

Things to note:

  • During the second half of 2006, the CTA will be running a trial routing plan on the Blue Line. The Cermak/Douglas branch, instead of merging with the Forest Park/Congress branch, will continue north to Lake Street (Green Line tracks), where it will then turn east and terminate in the Loop. This route is shown as *s, but stations along it are not marked. For more information, please see the Circle Line writeup.
  • All stations have some form of warming-shelter on their platforms. Usually, there is a bus-shelter with heat lamps. Though these are not the best in the world, they do provide some warmth and protection from the wind during the winter.
  • Most stations have Pepsi vending machines (20 oz $1.00), and some also have convenience stores.
  • The CTA uses electric trains, which run off of power from a third rail. Therefore, it is imperative that you stay off the tracks!
  • All train cars have an intercom system to the motorman, located on a panel next to the wheelchair-accessible seat by the cab of each car. This can be used in an emergency, or by customers with disabilities to alert the motorman to wait until they have exited the train.
  • Though all runs are accessible, all stations are not. In addition, most runs have some accessible and some non-accessible cars. For those who need full-width doors, either for wheelchairs or luggage, accessible cars are often located in the front and back of a 6- or 8-car run. The middle two or four cars are older, and have blinker-style doors, which do not provide enough space for a wheelchair to fit through.

Credit to: http://www.transitchicago.com, http://www.chicago-l.org, personal knowledge.