I believe the "double signage" is thanks to the very sloppy construction crew that has been working on the corners on Clark street.
i saw confusing street cleaning signage yesterday. Permanent sign says no parking 9AM - 3PM 4th Wednesday of the month. Temporary Courtesy sign #1 says No parking 9AM - 1PM WEDNESDAY. courtesy sign #2 says No parking 9AM - 3PM WEDNESDAY. Which is it?
My partner and I noticed it the other day. It was before 6pm and we made a right turn and figured we'd blame sign #1 if we got pulled over. I prefer all-inclusive as opposed to restrictive.