Another thought:
Since they appear directional, they could be gunshot locators. These try to pinpoint where shots are fired based on sound.
I don’t think so. For one thing, there’s nothing that appears to be an opening for a microphone in the cover. Also, they’re located in the relatively crime-free middle class West End, and not at all in the more ghettofied low-income South Side.
Can you tell us where the cable coming out of this thing goes to?
I’m thinking is an omni directional antenna of some sort, but not sure what it does. Is there anything nearby that would work better if it were connected to a network? Traffic signals? Train crossings? Sewer lift stations? Natural gas regulating stations? I really suspect that is has to do with utilities of some sort.
Can you make out a manufacturer’s name or model number?