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Census Transportation Planning Package |
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Frequently Asked Questions
1. Census, ACS, and CTPP: Some General Information and Trouble Shooting (March 13, 2007):Census 2010Census 2010 will be only a SHORT FORM Census. This means NO LONG FORM questions. The LONG FORM questions are asked in a continuous survey called the American Community Survey (www.census.gov/acs/www). For a list of questions in Census 2010, please see an article in the Wall Street Journal Feb 23, 2007. There are 6 basic questions and an additional 3 for "householder" which have not yet been determined. American Community SurveyPlease see http://www.fhwa.dot.gov/planning/census/acs.htm This link includes links to training on ACS and a new book by Cynthia Taueber. Census Transportation Planning PackageMain website: http://www.fhwa.dot.gov/ctpp/ Training: http://www.fhwa.dot.gov/ctpp/training.htm Trouble shooting CTPP Software:A copy of the tutorial is posted at ftp://ftp.camsys.com/clientsupport/CTPPdata/software/tutorial2.exe
2. What data are available from the CTPP?For both 1990 and 2000, the following data sets are available:
In addition, the data sets may be broken down into following geographies (varies for each data set and time period):
3. How do I access CTPP data?Please refer to the Data Products page for accessing CTPP data. 4. What are some uses of CTPP data?Please refer to the following status reports for some applications of CTPP data:
5. How did the CTPP come about?Please click here for more information on the history of the CTPP. 6. There are three Parts included in CTPP data: what are they and how do they differ?The CTPP 2000 is divided into three parts:
The CTPP 1990 is divided into three parts: Statewide
Urban
To learn more and access CTPP data products, visit the Data Products page. 7. How do the 1990 and 2000 CTPP data sets differ?
8. I have installed the CTPP cd-rom on my Windows XP PC, but the session window closes and I get the error: "Beyond 2020 caused an INI error." What do I do?Make sure the session is closed, restart the software, and click on the open session folder. 9. The CTPP software seems to be stuck on the "Select Geography" screen. How do I get past this?Verify your data path points to the folder containing the IVT files. Similarly, make sure you have a sessions folder and the software points to it correctly. 10. What are the tables available in CTPP 2000?11. What should I do when I get my CTPP CD with the CTPP Access Tool a.k.a the Browser?
Also read the following for PART 3.
12. Why do my employment numbers in CTPP look lower than total employment in my area?Please see http://www.fhwa.dot.gov/ctpp/ctppatwork.htm and http://www.fhwa.dot.gov/ctpp/sr0503.htm "A discussion on some Census terms" Generally speaking, about 25 percent of workers do not provide sufficient information about workplace locations, so their workplace is imputed using travel time, travel mode, industry and occupation. Please refer to the following articles from the January, 2004 and the May, 2003 CTPP Status Reports for more in-depth information on accessing and understanding CTPP data: "CTPP Workers at Work Compared to Other Employment Estimates" and "A discussion on some Census terms" respectively. Also, click here for an article on "CTPP Workers-at-Work Compared to Other Employment Estimates" . 13. Why do my Part 3 tables look so odd?SOME of the Part 3 tables were subject to THRESHOLDS. All of the CTPP is subject to ROUNDING. Part 3 Tables 1 and 2 are NOT subject to thresholds. Please see http://www.fhwa.dot.gov/ctpp/balance.htm and also see Using Tables from Part 3 of CTPP: A note of caution However, those subject to the thresholds have a LOT of SUPPRESSION for small geography. http://www.trbcensus.com/notes/small_area_data.pdf One way to get around rounding and thresholds for Part 3 is to use Table 3-14 and Table 3-8. For instructions, please see http://www.chrispy.net/pipermail/ctpp-news/2005-May/001338.html |
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