ctpp-news May 2004

ctpp-news@mailman.chrispy.net

11 participants
16 discussions

State DOT and MPO Review of CTPP 2000 Part 3 Data

by phillip.a.salopek＠census.gov

State Departments of Transportation and Metropolitan Planning Organizations: As announced earlier this week, all the CTPP 2000 Part 3 files (journey-to-work flow data) are now available in ASCII format for downloading from the BTS TranStats website at http://www.transtats.bts.dot.gov. Unlike Parts 1 and 2, only these ASCII files will be available for Part 3 in a preliminary version for review by the State DOTs and MPOs. The reason for this is that we will not have a revised version of the CTPP Access Tool (CAT) software that can handle the Part 3 flow data soon enough to be used in the review. We encourage you to download the ASCII files for your area and evaluate the data as soon as you can. To assist you in your review we have provided a data dictionary, Microsoft Access template, and dbase specs file for Part 3. The files in Part 3 are more manageable than the previous CTPP 2000 data because there are fewer tables and the records are therefore shorter. However, there are large numbers of records in some of the files so the databases can still be quite big. Errors that come to our attention based on review of the ASCII files will be fixed before the CAT software version of the data become available. We expect to distribute the CAT software version of the final Part 3 data late this summer. Stay tuned to the CTPP listserve for details. --Phil Salopek Chief, Journey to Work and Migration Statistics Branch U.S. Census Bureau (301) 763-2454

21 years, 12 months

American Community Survey Alert, Number 21.wpd

by Margaret Shaw

American Community Survey Alert, Number 21.wpd

21 years, 12 months

A letter from the Chief of the ACS office

by Pheny Smith

** High Priority ** Dear CTPP data Users, Attached please find a copy of a letter from Mr. Larry McGinn, Chief, American Community Survey Office/Census Bureau. As you were aware of from a previous ctpp-list server announcement, the Census Bureau published a Federal Register notice soliciting comments from current and potential users of ACS data products to help guide the redesign of these products on May 14, 2004. Mr. McGinn's letter provides more detailed explanation on why certain products are included. I hope that you will find it helpful while you are critiquing current ACS products. Thanks for taking time to making comments. Pheny Smith, Ph. D. DOT ACS Federal Agency Information Program (FAIP) Liaison Office of Advanced Studies Bureau of Transportation Statistics

22 years

Release of CTPP 2000 Part III detailed Geograpgy files

by Pheny Smith

** High Priority ** Dear CTPP Users, You can now download CTPP 2000 Part III detailed Geography files from the BTS' Transtats site beginning May 21, 2004. Together, with previously released Part III flat files, the complete set of CTPP 2000 Part III preliminary tables have been released. Please note that the Part III data are PRELIMINARY, and are undergoing evaluation by State DOTs and MPOs. Once these agencies examine the data and ensure that there were no processing errors, Census Bureau will finalize the data, and we will post the final files to the BTS TranStats Website. Data documentation, SAS programs, and MS Access Template are provided in the zipped folder for each state. For questions on these files, please contact Nanda Srinivasan at FHWA (Phone: 202-366-5021, e:mail: nanda.srinivasan(a)fhwa.dot.gov). A big thanks goes to the BTS Transtats team members for making these files available to us in such a short time frame. Hope all of you having great fun playing with the data. With regards, Pheny Smith, Ph. D. Office of Advanced Studies Bureau of Transportation Statistics

22 years

RE: [CTPP] Release of CTPP Part 3 Flat ASCII files

by Ken Cervenka

hmmm...thanks for the reminder, Chuck: The person living in Alaska but working in Dallas during the "reference week" might be noting: -- 20 minutes as his/her trip from the "regular" home in Alaska to the "regular" workplace in Alaska. -- 20 minutes as his/her trip from the "reference week" home in Dallas to the "reference week" workplace in Dallas. Either way, it seems that such a trip (as well as others that fit some category of strangeness) should simply be dropped from most journey-to-work regional analysis. Which brings up a subsequent question: Should a Planner simply drop those kinds of trips from a travel pattern analysis, or perhaps "expand" the remaining zone-to-zone trips in such a way that the original Census-estimated number of workers in the "place of work" zone is still preserved? The good news is that the percentage of zone-to-zone trips that fit this strange category of a temporary "reference week" workplace that requires a different temporary "reference week" home place is not very large. Ken C. -----Original Message----- From: Chuck Purvis [mailto:CPurvis@mtc.ca.gov] Sent: Friday, May 21, 2004 10:42 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Release of CTPP Part 3 Flat ASCII files Hey Ken: The ultra-long distance commuters I just throw away. I put them in the same bucket as the weekly absentees. Or, it may help to try to sort the commute data into: commutes from home-to-work; and, commutes from "not home"-to-work. (Note that the census doesn't ask where you started your commute, it asks: "at what location did this person work last week?" Though the question on commute time departure *does* ask: "What time did this person usually leave home to go to work last week?") For interregional commuters, I use my common sense and select the counties neighboring my region that have legitimate opportunities for daily commute trips. Perhaps this is a three-hour maximum from the edge of the region? Counties in California are fairly large, so I use just 12 neighbor counties surrounding the SF Bay Area. Texas has MANY smaller-sized counties, so I imagine you would have an inner ring and outer ring(s) of surrounding / neighboring counties. Then, if you have time, you can build some tract-to-tract desire lines (with distance) to calculate the tract-to-tract distances, reported average commute duration, and derived commute speed, to determine if the interregional commutes are sensible or silly. I don't know what I would do with a seemingly reasonable interregional commute value that has a unreasonable travel time - - perhaps the travel time is mis-coded, or perhaps this is another case where the worker is NOT starting their commute from THEIR home!? I would probably accept the numbers of commuters value, but blank out the commute time as a missing value. Another idea is to use the statewide travel model system to build a statewide zone-to-zone commuter matrix, then develop commute length (distance) frequency distributions to isolate the ultra-long, intra-state commutes, their reported commute durations, and the derived commute speeds. That would be preferable to a crow-flow distance desire line analysis. (By the way, I haven't tested any of these methods. They're just some ideas to share.) Chuck Purvis, MTC >>> Ken Cervenka <kcervenka(a)nctcog.org> 05/18/04 03:56PM >>> This question has probably been asked before, but I don't recall the answer... What sort of adjustments do people make with CTPP data, to deal with the extreme "long-distance" commuters that are actually just "temporarily re-assigned" workers? This is not an error in the CTPP collection or summary process, but rather a result of the way the long form questions were answered. For example, here is a record that got "expanded" to four people: -- The Place of Residence is a County in Alaska -- The Place of Work is a County in Texas (Dallas) -- The commute time is 20 minutes What this is saying is that the person isn't really commuting each day from their home in Alaska, but is instead commuting to a place in Dallas County from some temporary residence (a hotel, perhaps) within the Dallas-Fort Worth area. Such an extreme example is easy to recognize, but what about other examples which fall into the "not sure" category when it comes to whether a person's normal place of residence is really the point where they are truly starting their commute trip? Perhaps a very high "average speed" based on "travel time" and "straight-line distance" could be used to flag such records? Ken Cervenka North Central Texas COG

22 years

American Community Survey Alert, Number 21.wpd

by Margaret Shaw

This e-mail is from: Thabet Zakaria American Community Survey Alert, Number 21.wpd

22 years

unsubscribe

by Hanna Cockburn

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Hanna Cockburn, AICP Senior Planner Piedmont Triad Council of Governments Wilmington Building, Suite 201 2216 W. Meadowview Road Greensboro, NC 27407-3480 voice 336.294.4950 fax 336.632.0457 www.ptcog.org

22 years

RE: [CTPP] Mapping legend?

by Srinivasan, Nanda

Sam, The CTPP Access Tool allows you to save the legend to a "GeoTrack Legend" format (.gtl). But, I've found no way to get this into MS Word. However, I clicked on EDIT LEGEND, printed the Screen (used the "Print Screen" button on the key board), brought it into MS Word (CNTRL + V), and then CROPPED the picture (Right clicked on the picture, then clicked on "Format Picture", "Picture", "Crop from"). See attached MS Word for a sample. Nanda Srinivasan -----Original Message----- From: Shea, Sam J. [mailto:S.Shea@cedar-rapids.org] Sent: Friday, May 21, 2004 4:40 PM To: ctpp-news(a)chrispy.net Subject: [CTPP] Mapping legend? I am trying to cut and paste a thematic map from the CTPP mapping function into another document. I can not seem to locate a legend to paste with it in the document. Does anyone know how to display the legend, and paste it into another document? Thanks, Sam J. Shea Long Range Planning Coordinator Cedar Rapids Development Dept. 50 Second Ave Bridge Cedar Rapids IA. 52401 Ph. (319)286-5042 Fx.(319)286-5141 "Everything in Life is Somewhere Else, and You Get There in a Car." -E.B. White

22 years

Mapping legend?

by Shea, Sam J.

I am trying to cut and paste a thematic map from the CTPP mapping function into another document. I can not seem to locate a legend to paste with it in the document. Does anyone know how to display the legend, and paste it into another document? Thanks, Sam J. Shea Long Range Planning Coordinator Cedar Rapids Development Dept. 50 Second Ave Bridge Cedar Rapids IA. 52401 Ph. (319)286-5042 Fx.(319)286-5141 "Everything in Life is Somewhere Else, and You Get There in a Car." -E.B. White

22 years

Re: [CTPP] Release of CTPP Part 3 Flat ASCII files

by Chuck Purvis

Hey Ken: The ultra-long distance commuters I just throw away. I put them in the same bucket as the weekly absentees. Or, it may help to try to sort the commute data into: commutes from home-to-work; and, commutes from "not home"-to-work. (Note that the census doesn't ask where you started your commute, it asks: "at what location did this person work last week?" Though the question on commute time departure *does* ask: "What time did this person usually leave home to go to work last week?") For interregional commuters, I use my common sense and select the counties neighboring my region that have legitimate opportunities for daily commute trips. Perhaps this is a three-hour maximum from the edge of the region? Counties in California are fairly large, so I use just 12 neighbor counties surrounding the SF Bay Area. Texas has MANY smaller-sized counties, so I imagine you would have an inner ring and outer ring(s) of surrounding / neighboring counties. Then, if you have time, you can build some tract-to-tract desire lines (with distance) to calculate the tract-to-tract distances, reported average commute duration, and derived commute speed, to determine if the interregional commutes are sensible or silly. I don't know what I would do with a seemingly reasonable interregional commute value that has a unreasonable travel time - - perhaps the travel time is mis-coded, or perhaps this is another case where the worker is NOT starting their commute from THEIR home!? I would probably accept the numbers of commuters value, but blank out the commute time as a missing value. Another idea is to use the statewide travel model system to build a statewide zone-to-zone commuter matrix, then develop commute length (distance) frequency distributions to isolate the ultra-long, intra-state commutes, their reported commute durations, and the derived commute speeds. That would be preferable to a crow-flow distance desire line analysis. (By the way, I haven't tested any of these methods. They're just some ideas to share.) Chuck Purvis, MTC >>> Ken Cervenka <kcervenka(a)nctcog.org> 05/18/04 03:56PM >>> This question has probably been asked before, but I don't recall the answer... What sort of adjustments do people make with CTPP data, to deal with the extreme "long-distance" commuters that are actually just "temporarily re-assigned" workers? This is not an error in the CTPP collection or summary process, but rather a result of the way the long form questions were answered. For example, here is a record that got "expanded" to four people: -- The Place of Residence is a County in Alaska -- The Place of Work is a County in Texas (Dallas) -- The commute time is 20 minutes What this is saying is that the person isn't really commuting each day from their home in Alaska, but is instead commuting to a place in Dallas County from some temporary residence (a hotel, perhaps) within the Dallas-Fort Worth area. Such an extreme example is easy to recognize, but what about other examples which fall into the "not sure" category when it comes to whether a person's normal place of residence is really the point where they are truly starting their commute trip? Perhaps a very high "average speed" based on "travel time" and "straight-line distance" could be used to flag such records? Ken Cervenka North Central Texas COG

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ctpp-news May 2004