|Cincinnati, Ohio, United States|
|latitude: 39.1, longitude: -84.516667|
|Browse map of Cincinnati 39°06′00″ N, 84°31′00″ W|
|Use this template for your city|
|OpenStreetMap images (and underlying map data) are freely available under the OpenStreetMap License.|
The Tri-State area has pretty good OSM coverage for an American metropolitan area, with extensive building footprints, transit routes, named landuse areas, footpaths and staircases, cul-de-sacs, and the beginnings of 3D building support (example). Virtually all roads imported from TIGER have been redrawn.
That said, there are infinite opportunities for improvement! Greater Cincinnati has seen a lot of activity over the past few years, but Northern Kentucky is quickly improving and we're starting to pay some attention to Southeast Indiana too. We may have a lot of buildings mapped, but hardly any have addresses on them. A great way to start is to zoom all the way into your neighborhood and add as much detail as you can. Even toolsheds are fair game.
The default aerial imagery layers in iD and Potlatch are of high resolution but date back a couple years, so check the vintage of an OSM feature before remapping it based on aerial imagery.
This table of corn mazes gives a good idea of the vintage of each aerial imagery layer by county. The Bing aerial imagery analyzer is another tool for determining Bing imagery vintage, although these days it only reports a very broad date range. Through the National Agriculture Imagery Program, Ohio has published aerial imagery from 2015, but it has very low resolution compared to Bing and Mapbox, and it isn't compatible with the online editors iD and Potlatch 2.
In 2017, Miami University organized a mapping party to help the Humanitarian OSM Team map Puerto Rico following Hurricane Maria.  However, there hasn't been a meetup or mapping party focused on the Tri-State area – you're welcome to start one.
Find non-wiki-using mappers using Who's around me? Be sure to subscribe to the talk-us mailing list, where the broader U.S. mapping community discusses tagging, imports, policy, evangelization, and more. If you have any questions, you can also ask on the U.S. community's Slack channels, where you might encounter a Cincinnatian happy to help.
Please introduce your friends to OpenStreetMap! Reach out to enthusiast communities in orienteering, urban planning, and open source. Show a local trivia buff the old_name=* tag; show a road fan the route networks page.
OSM in the wild
- The Cincinnati Bike Map, published in September of 2014, is entirely based on OSM data. 9,000 copies of the map were printed for free local distribution. It is available online and by mail on request.
- Go Solar Cincy, a project of OKI, uses building footprint data from OSM to supplement those from institutional data sources in their web map.
- The websites of the Enquirer and channels 5 (WLWT-TV, NBC), 12.1 (WKRC-TV, CBS), 12.2 (WKRC-TV, CW), 19 (WXIX-TV, Fox), and 64 (WSTR-TV, MyNetworkTV) all plot their Doppler radar against an OSM-based basemap by Mapbox.
- Bus Detective, a local real-time transit app, locates stops on the Humanitarian OSM Team (HOT) basemap.
- Cincy 311 plots 311 calls against the HOT basemap.
- Cincinnati St. Vincent de Paul plots its locations against the standard OSM basemap.
- The Butler County RTA plots bus routes against the standard OSM basemap (example).
- The University of Cincinnati shuttle service operates an online route map atop an OSM-based basemap powered by Mapbox.
Acknowledging that everything can always be better, this is a list of things which are, for now, really quite accurate and thoroughly identified. Please add more things to this list if you've made a point of seeing that some particular thing in Greater Cincinnati has been mapped to the fullest; it's good to know what our strengths are!
- Over 160,000 buildings , every single one of them hand-drawn
- Turning circles (There are more than 10,000 identified in the metro area!)
- Marked pedestrian crossings (around 9,000 identified)
- Coffee shops and bike shops for now, though such places are always changing
- Schools and universities 
- Street geometry and names have generally been vetted pretty thoroughly
- Cincinnati neighborhood retail areas
- Park boundaries and sports pitches in Cincinnati proper
- High-voltage power lines and towers
- Alleys are increasingly well-tagged. Almost all alleys are identified (service=alley), though many can still use names and other information.
- Cycleways (bike paths, bike lanes and trails)
- lanes=* on primary, secondary and tertiary streets
- Golf courses (although details like golf cart paths, holes, and fairways are missing on many golf courses)
- The Cincinnati Southern Railway (owned by the City of Cincinnati) is completely mapped to Chattanooga, although sidings, spurs, and level crossings are lacking in many places.
Plenty of room for improvement
- Add street details like sidewalks, lane counts, speed limits, widths, lighting, and speed bumps
- Add public transit routes and stops, which can be found in public GTFS feed data.
- Add businesses and building names pretty much everywhere.
- Map and name residential subdivisions and shopping centers (they can get prominent labels, based on zoom level and area).
- Classifying building=* tags, from a simple building=yes to something more informative. (apartments, retail, garage, house, church, etc.) 
- Add tree cover in suburban and rural areas.
- Add City of Cincinnati neighborhood boundaries as admin_level=10 relations.
- Clean up buildings that were drawn based on grainy Yahoo! aerial imagery.
- Make sense of neighborhood names within Covington.
- Add more 3D building data, particularly building heights.
- Add retreat=yes to any Safe Place you come across (mostly fire stations, community centers, churches, and chain retailers).
- Improve the map's suitability for routing and turn-by-turn navigation:
- Add access=* tags to service roads on private property.
- The urban NKY cities need ground-verification of the directionality of their streets. There are almost certainly more one-way streets than are identified yet. Tag known two-ways as oneway=no.
- Indicate signalization at intersections, whether stop signs or traffic signals.
- Replace exit_to=* with destination=* and destination:ref=* (and occasionally destination:street=* in Kentucky) on I-71 in Warren County, I-71/75 south of I-275, SR 128, and SR 32 east of I-275.
- Replace note:lanes=* with lanes:forward=* and lanes:backward=*.
- Tag turn lanes with turn:lanes=*, turn:lanes:forward=*, and turn:lanes:backward=*.
- Add maxspeed:advisory=* to tight curves and highway ramps.
- Clarify easily mispronounced street names, particularly those of German origin, with name:pronunciation=* and destination:pronunciation=*.