This is the CTA (Chicago Transit Authority) system. We have 8 lines I believe, that is train systems.
1.The Brown Line (which goes from Albany Park to the Loop)
2. The Blue Line (goes from O’hare Airport to Forest Park)
3. The Orange Line (goes from Midway Airport towards the loop)
4. The Purple Line (goes from Evanston into the loop)
5. The Green Line (goes from Oak Park into the loop, and then towards Engel Wood)
6. The Pink Line (goes the loop to Little Village and passed 54th)
7. The Yellow Line (goes from Skokie into the Howard stop)
8. The Red Line (goes from Howard station, all the way to 97th/Dan Ryan)
So these trains go pretty far south, north, a bit west, and a bit east. I scanned this from my Moleskine Chicago. I live close to the Brown Line, and shy from the Blue line. Normally if I take the train to work, I take the brown line. It drops me right off.