Having to go all of the way through downtown to a destination that's a few miles north or south of you is a waste.

Everybody says Chicago needs a circumfrential line. Here's one of three.

It would start at Howard tunneling under Rogers Park until it hit Clark.

There should be a stop at Lunt and Clark, near the Metra station. Other than the stops should just be 4-6 blocks apart in this dense area
As Clark meets Ashland the Yellow line meets with the Grey line and heads down Ashland. More Businesses are on Clark, but Ashland is alot wider and is only like a block away.

At Ashland and Wilson there's a Transfer with the Turqoise line to O'Hare, and the Yellow heads off alone.

It comes out of the ground and meets up with the Brown Line South of Montrose.

At around Lincoln, or that old Mazda dealership it heads underground and zooms under Ashland, making stops every four blocks.

See all of the lines it has transfers with? Tres utile!

South of Lake it can use the old tracks that still stand along Paulina, it then shares track with the Douglas trains, and and then loops off to a transfer point with the Orange and Purple Lines.