RE: [CTPP] RE: [CPP] While you are waiting for the CPP full datarelease.......

Collapsing is when a variable is reported across fewer categories so that there are fewer cells to populate so there is an increased chance of getting (albeit less granular) data returned. For example, the uncollapsed variable Means of Transportation has 18 categories. There are 4 collapsed versions of the variable, where such categories as number in carpool become less refined (2 or more, as opposed to 2, 3, 4, 5 or more each as their own category) alternatives to driving may collapse as well, collapsing is grouping - rather than a category for biking and one for walking, they are grouped into biked, walked, to capture more cases. In a variable like income or age, the range would be larger in a collapsed category, all the cases are allocated to fewer categories so that each cell may have more cases, so data will have less chance of suppression (not meeting the minimum cell requirements imposed by the census bureau). I hope this helps, and does not further confuse. Penelope Weinberger CTPP Program Manager AASHTO 202-624-3556 http://ctpp.transportation.org/Pages/default.aspx <http://ctpp.transportation.org/Pages/default.aspx> It's just as bad to not make a plan as to blindly follow the one you already have. From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Michael Moan Sent: Monday, November 22, 2010 10:43 AM To: ctpp-news(a)chrispy.net Subject: [CTPP] RE: [CPP] While you are waiting for the CPP full datarelease....... Could some please explain "collapsing" again and the affect it will have on Cpp and modeling? Michael C. Moan, Principal Planner Office of Statewide Planning Division of Planning Department of Administration One Capitol Hill Providence, RI 02908 4012221236 To see the list of tables that constitute the CTPP 3-year special tabulation based on 2006 - 2008 ACS go to http://ctpp.transportation.org/Pages/ACSData.aspx and click on the "Link to the list of tables" under the three year data heading. That will return the spreadsheet of part one (residence based), two (workplace based) and three (flow) tables, with geography. What will be released is those tables together with a data access tool, currently under development (Beta testing now), to access the data for analysis. Penelope Weinberger CTPP Program Manager AASHTO 202-624-3556 http://ctpp.transportation.org/Pages/default.aspx It's just as bad to not make a plan as to blindly follow the one you already have. -----Original Message----- From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Garth Banninga Sent: Friday, November 19, 2010 4:13 PM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] While you are waiting for the CTPP full data release....... Liang: Exactly what data will be included in the December CTPP release? CTPP2000 and ACS 2007-2009? or some other periods? I'd appreciate any clarifications or references you can provide. Thanks, Garth Banninga, Planner MDOT-Planning Statewide Model Unit 425 W. Ottawa St. Lansing, MI 48933 517.335.2959 While you are still waiting for the CTPP full data release with the access software (scheduled on December, 2010), don't forget FHWA prepared and released the county-to-county and place-to-place flow tables prior to full data's formal release. The flow tables are for Total Workers and for 18 categories of Workers by Means of Transportation. County level data also included CTPP 2000 data but categorized only by 8 transportation modes. We have NOT included the CTPP2000 for Place-to-Place data files because of difficulties in matching FIPS codes for Places between 2000 and the current CTPP. These two files are published in CS FTP sites: ftp://ftp.camsys.com/temp/outgoing/CTPP/New%20CTPP%20ACS/ Also, transportation profiles using ACS 2005-2007 and CTPP2000, which give people a quick transportation snapshot of their areas are also published at AASHTO CTPP website. http://download.ctpp.transportation.org/profiles_2005-2007/ctpp_profiles .html Liang Long Federal Highway Administration Room 74-440 1200 New Jersey, SE Washington, DC 20590 tel 202 366 6971 fax 202 493 2198 e-mail liang.long(a)dot.gov <mailto:liang.long@dot.gov> _______________________________________________ ctpp-news mailing list ctpp-news(a)chrispy.net http://www.chrispy.net/mailman/listinfo/ctpp-news _______________________________________________ ctpp-news mailing list ctpp-news(a)chrispy.net http://www.chrispy.net/mailman/listinfo/ctpp-news