Craig Berman has an interesting feature over at Gapers Block about Chicago's El. He starts out by detailing the plans for a circle line and the progress that has been made so far; then he turns to his own proposals, which range from insightful but unlikely to pie in the sky. Maybe I'm a public transportation geek, but I had a lot of fun poring over the maps he put together.
For me the most important point he made was about the bottom of the proposed circle line, which fails to extend all the way around to the Red and Green Lines, effectively isolating the south side:
Let's complete the "Circle Line" by connecting the Orange, Red, and Green Lines on the South Side. This final spur would truly complete the Circle Line by running a subway from the Ashland Orange Line stop, down 35th street through Bridgeport, and terminating at a "Superstation" that would link the Circle Line to the 35th/Sox Red Line stop and the 35th/Bronzeville-IIT Green Line stop. The Circle Line would live up to its name and break the rapid transit boundary between the South and the Southwest Sides.It's hard to believe the plan appeared at all with this glaring omission. The boundary he's talking about is more than just a rapid transit boundary; it's a hard border in the form of the Dan Ryan Expressway, engineered by Richard J. Daley to keep the south side (and its residents!) separate from the rest of the city. Shouldn't efforts be made to include them now? It's amazing how little things change.
I suppose you could look at this in terms of usage and who wants to get where; maybe they've done some research to see who wants to go where, and based their plans on the need. But this gets to Berman's point about the El as an enabler. Any time you're talking about transportation there has to be a kind of build it and they will come mentality, since naturally it's hard to project future need of a resource without some provision of it in the present.