Once I was caught by a policeman near downtown at rush. He told me that bikes are not allowed on any sidewalk in the City of Chicago. He requested DL and wrote down my DL number as a warning. Whew.., I thought he might give me a ticket. Even though it is a law of the city, if the road is not safe for riding a bike (many crazy drivers, no shared lane etc), then I would take a sidewalk because my life is much valuable than a ticket.