As far as I know, the
Dan Ryan Red Line rehab work is done. There might be a few random checklist items remaining, but all major construction and delays are over. Same goes for the reconstruction of the Dan Ryan itself.
Currently, the
Red Line has a track rehab going on in the subway, and between Diversey and Wellington on the North Side, that should also be done by the end of 2008. After that, track rehab will work on portions further north.
The
Blue Line has two projects going on - a signal system replacement and a track rehab. The track rehab is expected to be completed by the end of 2008. The signal project might extend into 2009, since the track work is getting priority, but I don't think it will cause significant delays.
If major construction on the city's two busiest lines wasn't enough, there is also a rehab project that's set to start work on the
Lake/Wabash half of the Loop, so all trains will be shifted to the other half (Van Buren/Wells). Service patterns will change while construction is ongoing. The interesting thing about this is that, when the Lake/Wabash side is closed, Brown and Orange Lines will essentially be combined, with trains operating from Kimball to Midway. The Pink Line will not go to the Loop, and will terminate at Ashland/Lake. This project is also planned to complete by the end of 2008.
In short, 2008 will be
absolute transit hell, between North Side 3-tracking, city-wide slow zone work, and a few other projects, with every line affected except Yellow. But come January, the system should improve by a tremendous amount. In the meantime, improvements will come in the form of increased Bus Tracker, new Brown Line stations opening, and maybe the installation of station improvements like the ad/info screens. The Loop closures will also make it a bit easier for the Wabash repainting/streetscaping to continue.
Complete information can be found here, along with links to the latest closure/delay updates.
http://www.transitchicago.com/news/motion/szep.html