“Too tantalizing to public officials”? Please explain. The city is run by nine elected members of the council. For what possible purpose would they wish to have audio recordings of street traffic?
That means they are planning to use audio recordings.
This is clearly not about recording audio of vehicle traffic, but about recording conversations between the same citizens they're visually monitoring.
Plus, they were very quick to pull the trigger and install these without asking. Clearly asking people who would do such a thing to "exercise self control" in regard to enabling yet another degree of surveillance seems like an exercise in futility.