Chicago already has a subway train from O'Hare to the loop. It takes ~40 minutes to get downtown and is often crowded (and at night may have homeless people sle

Chicago already has a subway train from O'Hare to the loop. It takes ~40 minutes to get downtown and is often crowded (and at night may have homeless people sleeping in it), but a normal express train would usually not beat it in time (an express train might be twice as fast, but won't come as often), so something like this becomes attractive. Also, the previous Mayor built a massive hole in the ground downtown for an express train, and it makes it look less bad if it's used.