Hi Mark, Thanks for the explanation! I’m looking at Montgomery county as an example, but had trouble duplicate the results. I’m assuming that the trip distance filter was the cause. I wonder how you apply the trip distance filter? Is it defined by distance between centroids of residence and workplace tracts? Thanks, JJ *From:* ctpp-news-bounces(a)chrispy.net [mailto: ctpp-news-bounces(a)chrispy.net] *On Behalf Of *Mark Evans *Sent:* Thursday, May 26, 2016 3:34 PM *To:* ctpp-news(a)chrispy.net *Subject:* [CTPP] ACS Commute Visualization Hey - hope this goes through. I'm Mark Evans and I developed the commuter map. Ed Christopher told me about this listserv. I'm happy to answer any questions that you may have. I think Penelope mentioned it elsewhere, but the data is from the 2006-2010 ACS tract-tract commuter data <https://www.fhwa.dot.gov/planning/census_issues/ctpp/data_products/2006-2010_tract_flows/> . I calculated a CV using the estimate and the MOE. I've seen some warnings about the high level of error in some of the ACS data with recommendations to include only data with CV < 30-40%. Unfortunately, this removes almost all the data, so the default setting I used is 80%. Even at this high level, it excludes a portion of the estimated commuters at the tract level. In addition, anyone who works and lives in the same tract would not be included. Thanks for taking a look! _______________________________________________ ctpp-news mailing list ctpp-news(a)chrispy.net https://www.chrispy.net/mailman/listinfo/ctpp-news