i have just recently found out about this new CTA policy:
On Nov. 22, Mike Doyle of Chicago Carless fame wrote a well-researched piece about the CTA's newest efforts to crack down on what it calls "continous riders" -- passengers who ride to the end of a rail terminal and board another train going in the opposite direction. Often folks who do this are homeless.
Doyle is angry that the CTA should now start aggressively enforcing this rule, saying it's aimed squarely at the homeless: "It’s pretty clear who these new “continuous riding” signs are aimed at. I can’t imagine a reasonable Chicagoan believing that homeless people are not the obvious and only target here."
"to remind CTA customers of the policy which prohibits customers from continuously riding the same line without payment of another fare, and as an aid to law enforcement in dealing with violators of this rule.”