I talked with my friend Jim Church who is a documents librarian at UC-Berkeley. He is outgoing chair of the State and Local Documents Task Force (SLDTF) - part of the American Library Association. He had a few suggestions:
1> "there are gazillions of cities in "North America" :) so it is difficult to make a generalization about all of them without a large survey."
2> "SLDTF has a committee of 8 that is charged with getting questions out like this to their respective states. I wish there was some kind of listserv that addresses local documents issues, but I know of none." There is a general list for Government Documents Librarians - GOVDOC-L. If you're interested in what other people with municpal documents responsibilities have to say we could point you there or I could facilitate a request for information.
3> Jim said that he had Municipal Documents librarian named Lyle Benedict, from Chicago Public, speak to SLDTF about HIS municipal documents collection, which is exemplary. He noted it was one of the few left. Jim suspect's he may have some nation-wide perspective. benedict@chipublib.org
4> You may want to track down "Local and Regional Government Information: How to find it, how to use it." Edited by Mary Martin, Greenwood Press, 2005. It provides an overview of sources as well as identifies numerous issues related to government information.