Not sure if I'll get the time to do this but I was giving some thought to it. Does anyone know for certain if this is the NLCD impervious dataset that is being used in the criteria? http://www.mrlc.gov/nlcd06_data.php The Federal Register doesn't go into much detail on how the percent impervious area data is used in the criteria. Is the impervious area translated to census block geography (raster to vector)? The footnotes in the register suggest some subjectivity which would could make it difficult to incorporate into code. Dan Seidensticker GIS Specialist Madison Area Transportation Planning Board: A Metropolitan Planning Organization (MPO) City of Madison Planning Division 121 S. Pinckney Street, Suite 400 Madison, WI 53703 Voice: 608-266-9119 Fax: 608-261-9967 Email: dseidensticker(a)cityofmadison.com<mailto:dseidensticker(a)cityofmadison.com> www.MadisonAreaMPO.org<http://www.madisonareampo.org/> From: ctpp-news-bounces(a)chrispy.net<mailto:ctpp-news-bounces(a)chrispy.net> [mailto:ctpp-news-bounces(a)chrispy.net]<mailto:[mailto:ctpp-news-bounces(a)chrispy.net]> On Behalf Of Elaine.Murakami(a)dot.gov<mailto:Elaine.Murakami(a)dot.gov> Sent: Monday, September 26, 2011 1:57 PM To: ctpp-news(a)chrispy.net<mailto:ctpp-news(a)chrispy.net> Subject: [CTPP] Are you writing GIS code to estimate Urbanized Area Boundaries using 2010 Census I can't remember who told me they were writing some ArcGIS code to estimate what the Census Bureau's new urbanized (50,000+) areas might be, based on the CB's Federal Register notice of the final criteria. If you are willing to share your code, I think that there are others who would be interested in applying it in their own area. I checked with the Census Bureau Geography and they said they were NOT going to share their code. FHWA decided NOT to attempt this task, as we will just WAIT for the list and boundaries to be released from the Census Bureau. Elaine Murakami FHWA Office of Planning 206-220-4460 (in Seattle)