2017 data of BIDs with a KML file (that downloads as a KMZ file), shapefile, CSV (contains start dates), and Esri File Geodatabase: https://www.denvergov.org/opendata/dataset/city-and-county-of-denver-business-improvement-districts
===Columbus, OH===
2017 data of Neighborhood Commercial Revitalization Areas (=BIDs?) with a KML file: http://data-columbus.opendata.arcgis.com/datasets/a48bc3fc9a9b489089dfa41b5b994797_7
==Cities Not in Our Sample that have BID Data==