One of the problems we run into in portions of the midwest (like here in the St Louis area) is that the local county and municipal governments only lease the parcel data and don't own the data. They are not allowed to share that data without paying a large fee to the company who leases it to them. Here the company that leases the parcel data to the governments is Sidwell.
It might make getting parcel data released for geocoding purposes difficult in certain parts of the country. Rick Marshall On Thu, Nov 29, 2012 at 9:32 PM, Paul Johnson <ba...@ursamundi.org> wrote: > On Thursday, November 29, 2012, Brian May wrote: >> >> On 11/29/2012 9:12 PM, Steven Johnson wrote: >>> >>> >>> Secondly, about Census data... The Census Bureau publishes ZIP Code >>> Tabulation Areas (ZCTAs, as polygons) but they are an approximation of US >>> Postal Service data and used for downstream analytical purposes. But as far >>> as USPS is concerned, the ZIP code is a point data feature that only exists >>> to deliver the mail. The USPS does not maintain ZIP codes as polygons. >> >> For points coming from parcel centroids, Property Appraisers store mailing >> addresses, and they need to get that right in order to deliver the tax >> bills. When the owner mailing address and site address match, I would bet >> there is a high degree of accuracy for the city and zipcode values in the >> site address fields (where they are populated). > > > Is there a compelling reason not to get parcels instead? As parcels change > shape, the centroid can be easily interpolated. It's not really possible to > extrapolate geometry from centroid, however. > > _______________________________________________ > Talk-us mailing list > Talk-us@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-us > -- Rick Marshall, PhD, GISP President Vertical GeoSolutions, Inc (VerticalGeo) 130 Sawgrass Ln O'Fallon, IL 62269 (618) 670-4259 rick.marsh...@verticalgeo.com http://www.verticalgeo.com http://www.culturescapes.net Vertically Thinking Blog: http://verticalgeo.wordpress.com _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us