CTPP

ctpp@listserv.transportation.org

5 participants
3069 discussions

RE: [CTPP] Re: Geographic coverage, C2SS & ACS

by Don Burrell

Why do we have tracts? Yes, ed, your memory is correct about the Bureau "creating" census tracts, but they relied on the recommendations of the local "Census Tract Committees" of data users to provide the boundaries. This is still the process for the decennial review of the tracts. (I worked on coordinating this review in the Cincinnati CMSA for 1990 and 2000.) But, we have census tracts mainly as geographically stable over time statistical analytical areas. Municipalities, enumeration districts and zip-codes, on the other hand, keep moving their boundaries. This is also the reason that we can split census tracts in growing areas, but that they need to nest to the same parent tract of the preceding census, and that the ID tract numbers are changed with suffixes so that it is obvious that the areas represented by the tract-split numbers aren't the same. My experience with TAZ's, again with the Cincinnati MPO, is that you wouldn't want to go there. We have just overhauled our tazs for 2000. Most changes are splits, but some aren't. They don't match tracts. And many are small enough to represent blocks in the CBD and major traffic generators (shopping centers, employers) with little or no resident population to disclose. Census tracts are good. Don Burrell, Senior Planner Bicycle / Pedestrian Coordinator (formerly data person) OKI Regional Council of Governments 801-B West Eighth St. Suite 400 Cincinnati, OH 45203-1607 513-621-6300 513-621-9325 - fax dburrell(a)oki.org <mailto:dburrell(a)oki.org> <A bicycle is an instrument for playing the road> -----Original Message----- From: ed christopher [mailto:edc(a)berwyned.com] Sent: Thursday, November 08, 2001 4:37 PM To: 'ctpp-news maillist' Subject: Re: [CTPP] Re: Geographic coverage, C2SS & ACS since patty raised the issue of tracts, i have often wondered why do we have tracts? why don't we have a zonal system in urban areas that is created by the public data users--something like TAZs. in many areas the TAZs are developed by a collection agencies with planning and data responsibilities. if memory serves me tracts were historically a creation of the census bureau which is a data collector. TAZs are a product of regional planning organizations (which happen to have transportation responsibilities) which are data users. Patty Becker wrote: > Again, please feel free to post this to the list serve if you wish. > > My clear understanding is that "small area" means tract. I don't think > anyone thinks the 60 month data will be good enough for block groups. > > If TAZs are tract equivalent, then the data should be as good as for > tracts. For heavy attractor TAZs which are split below tract level, the > transportation community has to negotiate with the bureau for a special tab > to deliver all TAZs. The data should support the tab > adequately, Meanwhile, of course, someone is going to have to be > responsible (MPO by MPO and state by state) for keeping the geocoding file > up to date! > > No one knows whether these 60 month data are going to "feel right." Only > time will tell. But in any event the CTPP users will have data equivalent > to that for all users who use tracts. Meanwhile, we still have all these > hurdles in Congress, etc. etc. > > Patty Becker --- Ed Christopher Metropolitan Specialist Midwest Resource Center Federal Highway Administration 19900 Governors Drive Olympia Fields, Illinois 60461 708-283-3534 (V) 708-283-3501 (F)

23 years, 9 months

RE: [CTPP] Re: Geographic coverage, C2SS & ACS

by Mehta

Its my understanding that "Tracts" are based on population criteria (minimum, optimal, and maximum number of persons). TAZs may be too small in some cases to fit the "tract" definition, or may not have any population at all. . . Jamsheed Mehta, AICP Chief Planner, Transportation Division Wichita-Sedgwick County Metropolitan Area Planning Department Tel: (316) 268-4457 Fax: (316) 268-4390 e-mail: mehta_j(a)ci.wichita.ks.us -----Original Message----- From: ed christopher [mailto:edc(a)berwyned.com] Sent: Thursday, November 08, 2001 3:37 PM To: 'ctpp-news maillist' Subject: Re: [CTPP] Re: Geographic coverage, C2SS & ACS since patty raised the issue of tracts, i have often wondered why do we have tracts? why don't we have a zonal system in urban areas that is created by the public data users--something like TAZs. in many areas the TAZs are developed by a collection agencies with planning and data responsibilities. if memory serves me tracts were historically a creation of the census bureau which is a data collector. TAZs are a product of regional planning organizations (which happen to have transportation responsibilities) which are data users. Patty Becker wrote: > Again, please feel free to post this to the list serve if you wish. > > My clear understanding is that "small area" means tract. I don't think > anyone thinks the 60 month data will be good enough for block groups. > > If TAZs are tract equivalent, then the data should be as good as for > tracts. For heavy attractor TAZs which are split below tract level, the > transportation community has to negotiate with the bureau for a special tab > to deliver all TAZs. The data should support the tab > adequately, Meanwhile, of course, someone is going to have to be > responsible (MPO by MPO and state by state) for keeping the geocoding file > up to date! > > No one knows whether these 60 month data are going to "feel right." Only > time will tell. But in any event the CTPP users will have data equivalent > to that for all users who use tracts. Meanwhile, we still have all these > hurdles in Congress, etc. etc. > > Patty Becker --- Ed Christopher Metropolitan Specialist Midwest Resource Center Federal Highway Administration 19900 Governors Drive Olympia Fields, Illinois 60461 708-283-3534 (V) 708-283-3501 (F)

23 years, 9 months

[CTPP] Re: Geographic coverage, C2SS & ACS

by ed christopher

Elizabeth Hartmann wrote: > Hello, > I work in transportation planning, and we are currently evaluating data availability regarding the C2SS and the American Community Survey. I understand that the ACS will provide yearly info on population groups of 65,000 or more, and that for smaller areas, several years' data can be pooled to maximize reliability. > > Within this frame, at how fine a geographic level will this data be available? Currently, the decennial census provides data down to the block group level; will the C2SS and the ACS provide transportation data at this fine a level? > > Thank you! > Liz Hartmann, Ph.D. > Research Analysis Specialist > MNDOT:Office of Investment Management just to confirm what we spoke about on the phone. i cannot say with any certainty what the final geography will be with ACS nor even its content. as i noted, two efforts are underway within OBM. 1) to advise congress on the content and 2) on methodology (which impacts on geographic levels). how congress will respond is anyone's' guess. the mood in congress up to now has been to cut content and in january i am told the census issues will be moved over to another subcommittee that will have a chairman that is even more concerned about the questionnaire being "too" long. as far as getting ACS at a large scale geography (like the 65K areas) that should not be an issue. over the years we have been told that multiple years of ACS data can be pooled to produce small area summaries, but how small the areas will be and if this comes to pass, is not a done deal. most of the detail surrounding the ACS is still up in the air. in terms of the content, several of us within DOT have made our case to OMB on the importance and legal needs for the transportation related questions. i believe that right now OMB is review the information submitted by all the federal agencies and will reporting out on it sometime in the future--this is an issue we are following. i cross posted this to our ctpp-listserve for others who may have similar questions or who might be able to expound on any of the points raised. -- Ed Christopher Metropolitan Specialist Midwest Resource Center Federal Highway Administration 19900 Governors Drive Olympia Fields, Illinois 60461 708-283-3534 (V) 708-283-3501 (F)

23 years, 9 months

Re: [CTPP] Re: Geographic coverage, C2SS & ACS

by Patty Becker

Again, please feel free to post this to the list serve if you wish. My clear understanding is that "small area" means tract. I don't think anyone thinks the 60 month data will be good enough for block groups. If TAZs are tract equivalent, then the data should be as good as for tracts. For heavy attractor TAZs which are split below tract level, the transportation community has to negotiate with the bureau for a special tab to deliver all TAZs. The data should support the tab adequately, Meanwhile, of course, someone is going to have to be responsible (MPO by MPO and state by state) for keeping the geocoding file up to date! No one knows whether these 60 month data are going to "feel right." Only time will tell. But in any event the CTPP users will have data equivalent to that for all users who use tracts. Meanwhile, we still have all these hurdles in Congress, etc. etc. The C2Ss is separate from the ACS. There is no way that the number of cases will allow for TAZ level reporting, even if the 2000 and 2001 surveys are combined. Perhaps we can get combined data at the 100K level out of them next year. I would suggest, however, that the CTPP community keep a good handle on how the coding is proceeding for the C2SS--are they doing a good job of it? The ACS will be like the C2SS in this regard and if there are problems, it's important to be aware of them. Patty Becker At 02:05 PM 11/08/2001 -0600, ed christopher wrote: >Elizabeth and Ed-- (note, I am not posting this to the listserv, but Ed can >choose to post it if he wishes) > >At the current time, I believe that with the current plans for sampling for >the ACS, it would take 5 years of accumulated data (60 months) for the >Census Bureau to release small area data. However, if the sampling rate >decreases to any large extent, it is not clear what would happen to small >area data. To clarify Ed's earlier remarks, we do not know if "small area" >means census tract, or block group level geography. We are very concerned >about whether and how the transportation community will be able to generate >an "equivalent" to a CTPP file from the ACS, and if reporting by TAZ will be >possible or allowed. > >Elaine Murakami >Federal Highway Administration > >Keith Miller wrote: > > > According to the Census Bureau > > (http://www.census.gov/Press-Release/www/2001/ntc102901.html): > > > > "By 2004, the American Community Survey ... will produce estimates for > > geographic areas and population groups of 65,000 or more, and by 2008, for > > even the smallest areas and population groups in the country." > > > > Just what "the smallest areas and populations groups" means is anyone's > > guess, but it was my understanding that they're targeting the block-group > > level. But as Ed pointed out, this all depends on congress and funding... > > > > Also to address one point that Elizabeth asked in her original question, > > "will the C2SS and the ACS provide transportation data at this fine a level > > [block group]?" It is my understanding that the C2SS (Census 2000 > > Supplementary Survey) data will not be available for anything smaller than > > counties or cities with more than 250,000 residents. The sample size of the > > C2SS was not sufficient to support anything smaller than this. For the ACS, > > see above. > > > > ------------------------------------------------------------------------ > > Keith Miller > > Principal Planner: GIS and Modeling > > North Jersey Transportation Planning Authority, Inc. > > One Newark Center, 17th floor > > Newark, NJ 07102 > > 973-639-8444 > > kmiller(a)njtpa.org > > > > -----Original Message----- > > From: owner-ctpp-news(a)chrispy.net [mailto:owner-ctpp-news(a)chrispy.net]On > > Behalf Of ed christopher > > Sent: Wednesday, November 07, 2001 4:43 PM > > To: Elizabeth Hartmann > > Cc: elaine (fta) murakami; ctpp-news maillist > > Subject: [CTPP] Re: Geographic coverage, C2SS & ACS ------------------------------------------------------------------------------------------------- Patricia C. (Patty) Becker 248/354-6520 APB Associates/SEMCC FAX 248/354-6645 28300 Franklin Road Home 248/355-2428 Southfield, MI 48034 pbecker(a)umich.edu

23 years, 9 months

[CTPP] c2ss transportaton data

by ed christopher

In a coupla weeks the Census Bureau will be releasing the Census 2000 Supplementary Survey (C2SS) Data for cities and counties of 250,000 people or more. The C2SS was a 700,000-household survey that used the American Community Survey questionnaire and methods. In addition to the new data coming out, the TRB Subcommittee has established a web page with the transportation data elements of the C2SS. We have a power point presentation showing tables and maps of the data, excel spread sheets with the transportation variables by state-comparing 1990 and 2000, a written review of the findings and much more. Our web page can be found directly at http://www.TRBcensus.com/c2ss.html

23 years, 9 months

[CTPP] some more census data processing tools

by ed christopher

The following was sent to me by Nanda Srinivasan via Peter Van Demark, Caliper Corporation. ===================== Caliper Corporation includes nationwide geographic files with 2000 Census data with all of its GIS software products. These geographic files include states, counties, MSAs, census places, census tracts, and ZIP Code Tabulation Areas (ZCTAs). The 2000 Census data are profiles of the general demographic characteristics, based on SF 1. There are 71 population and 25 housing variables, which are based on the 100-percent data (questions asked of all people and about every housing unit). The variables describe sex, age, race, Hispanic or Latino household relationship, household type, group quarters population, housing occupancy, and housing tenure. These data can be used directly, without needing to download or assemble files. The fields have descriptive names, and moving the cursor over a column heading in a dataview shows extensive metadata for that column. Users of Maptitude for Redistricting have gotten PL94-171 data with the geographic files for blocks, VTDs, tracts, etc. for their state or county, and will be receiving complete SF 1 data, with a table chooser to make it easier to deal with the 82 tables and 8113 fields for tracts and above. These data are also available as Data CDs for users of other Caliper GIS software products. All of the Caliper GIS software products also include nationwide streets, based on TIGER/Line 2000, distributed on a single CD. This geographic file can be used for locating by address as well as displaying streets as a layer in your map. For more information, please visit our web site at (http://www.caliper.com). ---------------------------------------------------------------- Peter Van Demark Director of GIS Products and Training Phone: 617-527-4700 Caliper Corporation Fax: 617-527-5113 1172 Beacon Street E-mail: peter(a)caliper.com Newton MA 02461-9926 Web site: http://www.caliper.com

23 years, 9 months

[CTPP] Redistricting (PL-94-171) data and SF 1 data in shape file formats.

by Nanda Srinivasan

FYI Rick Ayers from ESRI sent me the attached note (inst.doc) that explains how to download redistricting data at the geographic detail of County - census blocks from the ESRI website at: www.geographynetwork.com. For those who want to convert Census data into ESRI shapefiles, I think the method Rick describes is easier to use than the one I wrote down to this listserve a while ago. Claritas Inc. is also making Census data available for free downloads from their website at: www.census.claritas.com. Thank you Nanda Srinivasan

23 years, 9 months

[CTPP] News Alert

by ed christopher

>From Census2000 <Census2000(a)ccmc.org> October 18, 2001 Census Bureau Says No To Adjustment; Review Finds Duplicates Wipe Out Most of Net Undercount Plus: Academy Panel Issues Report on Census 2000; Upcoming Advisory Committee Meetings; and more. The Census Bureau announced yesterday that it would not adjust Census 2000 data for non-political purposes, such as allocating federal program funds, citing a larger number of previously unidentified duplicates that reduced the net national undercount to "virtually zero in statistical terms." At a press conference in Washington, DC, Acting Bureau Director William Barron said he "concurred with and approved" the recommendation of the Executive Steering Committee for Accuracy and Coverage Evaluation Policy (ESCAP), which transmitted a report to him earlier this week, that unadjusted data should be used for non-redistricting purposes. He also said it would have been "a terrible mistake" to adjust the census counts issued to the states for redistricting last winter, based on the A.C.E. results. The bureau said that evaluation of "considerable new evidence" revealed that the Accuracy and Coverage Evaluation (A.C.E.) survey did not measure "a significant number" of double-counts and other counting mistakes (collectively called "erroneous enumerations"). As a result, the ESCAP found, the A.C.E. overstated the net national undercount by about three million people. The committee reported earlier this year that 3.1 million people were counted twice and an estimated 6.4 million people were missed in Census 2000, for a net national undercount of 3.3 million. The net undercount is the difference between the number of people counted twice or in the wrong place and the number of people missed, as measured by the post-census survey. The bureau issued preliminary revised undercount estimates that take into account the newly identified duplicates, bringing the net undercount down to 0.06 percent from the 1.18 percent reported last March. Higher proportions of racial minorities and Hispanics than Whites were missed in the census, although the gaps were smaller than in 1990. The revised undercount for the Black (non-Hispanic) population is 0.78 percent, compared to the 2.17 percent originally reported; the Hispanic undercount was lowered from 2.85 percent to 1.25 percent. The revised estimate for Whites and all other groups showed a small overcount of 0.28 percent, compared to an initial net undercount estimate of 0.73 percent. The 1990 census had a net national undercount of 1.6 percent, based on a similar though smaller quality-check survey. The ESCAP noted that the "net undercount remains disproportionately distributed among renters and minority populations." The committee said that further research might result in further revised estimates of undercounting or overcounting that could be used to improve the accuracy of the annual population estimates, particularly for harder-to-count demographic groups. At the press conference, Mr. Barron said the Census Bureau must start planning now for the 2010 census. He said he did not believe the bureau could ever complete an Accuracy and Coverage Evaluation program similar to the one fielded in 2000, in time to adjust the detailed census numbers issued to the states for redistricting within a year after Census Day. Congressman Dan Miller (R-FL), chairman of the Subcommittee on the Census, applauded the Census Bureau for "[choosing] the count that accurately shows real people, living in real neighborhoods and communities in a very real nation. We now know with scientific certainty, that a virtual census would have been less accurate than a real count." Referencing the Commerce Department's decision not to adjust the 1990 census based on a similar post-census survey, the chairman said, "We should give up on this twice failed experiment and put this money into improving the real count in 2010." Congressman William "Lacy" Clay (D-MO), the subcommittee's senior Democrat, called the bureau's decision "disappointing and troubling." He said the revised undercount estimates "do not allay the concerns of cities and communities seeking their fair share of funds for critical services. Despite many successes, Census 2000 still missed a lot of people in our poorer neighborhoods." Congressman Clay called on the bureau to release the adjusted numbers to assess the count's accuracy at the local level. Congresswoman Carolyn Maloney (D-NY), a subcommittee member, said the Census Bureau's decision "gave us more questions than answers," including why the bureau "conduct[ed] a search for duplicates but not conduct a search for omissions." She called on the Bush Administration to publicly release the adjusted data. Mr. Barron's statement and the ESCAP report are available through the Census Bureau's web site at <http://www.census.gov/Press-Release/www/2001/webcast10_17event.html>. National Academy of Sciences panel evaluates Census 2000: The National Research Council (NRC), an arm of the National Academy of Sciences, has issued a new report, "The 2000 Census: Interim Assessment." The Panel to Review the 2000 Census, chaired by former Bureau of Labor Statistics Commissioner Janet Norwood, assessed Census 2000 operations, including the Accuracy and Coverage Evaluation (A.C.E.) program and statistical imputation methods, based on information available through August 2001. The expert panel said Census 2000 was "well executed in many respects," and that adequate funding helped to keep operations on schedule. It called the A.C.E. program, designed to measure the net undercount (or overcount) in the census, "well planned and documented... and [generally] well executed." The panel did not offer an opinion on whether Census 2000 data should be adjusted based on the A.C.E., but concluded that the Census Bureau followed its plan for evaluating the census and A.C.E. results, and that the recommendation last March to release unadjusted numbers for redistricting purposes "was justifiable." Imputation, a statistical procedure used to count people about whom the Census Bureau has incomplete or no direct information, was largely responsible for the lower net undercount in 2000, the panel said. According to the report, the 2000 census included 5.8 million imputed people, three times the number imputed in the 1990 census. A disproportionate number of imputed persons were minorities, renters, and children, the panel found, "thus accounting in large part for the reduction in differential net undercount for these groups, relative to non-Hispanic whites, owners, and older people." The State of Utah has challenged the use of imputation in federal court, contending that the Census Act and the U.S. Constitution prohibit the use of statistical methods to compile the state population totals for congressional apportionment purposes. The panel also questioned the accuracy of the Census Bureau's independent population benchmark, compiled from administrative data such as birth, death, Medicare, and immigration records. The Demographic Analysis estimate of 279.6 million was lower than the raw census count (281.4 million) for the first time, and about 5 million below the A.C.E.-adjusted population estimate of 284.7 million. Focusing on the bureau's methods for gauging immigration and emigration, the Academy panel concluded that "demographic analysis should not be used as a standard for evaluation [of census accuracy] at this time." The Census Bureau had cited the discrepancy between the three measurements as a primary factor in its recommendation against releasing adjusted census data last March. Federal agencies and outside experts should research improved methods for estimating legal and undocumented immigration, the panel suggested. The panel singled out four successful innovations in Census 2000: contracting for data processing, with better technology to 'capture' responses on the forms; simplified questionnaires and a direct mail strategy to encourage response; the paid advertising campaign and expanded outreach; and aggressive recruitment of census takers. The higher-than-expected mail response rate -- about the same as in 1990 - was "an important achievement," the panel said, although areas with low mail-back rates in 1990 had similarly low response in 2000. The report also noted the "marked decline" in the mail-back rate for the census long form, which the panel cautioned could affect the quality of those data. The NRC report expressed concern about the quality of the count of people in so-called "group quarters," such as college dorms, prisons, and nursing homes. The panel also recommended further evaluation of procedures to build the national address list (called the "Master Address File," or MAF), to determine if the Local Update of Census Addresses (LUCA) program improved the accuracy of the MAF. While it made sense to seek address information from local and Tribal governments and the U.S. Postal Service, the panel said, "there were problems in execution that may have increased duplicate and erroneous enumerations." The National Research Council is part of the National Academy of Sciences. The report is available through the Internet at <www.nap.edu/books/0309076498/html/. Appropriations (funding) update: Congress is expected to pass a third "Continuing Resolution" to keep federal agencies running at fiscal year 2001 funding levels until lawmakers enact spending bills for fiscal year 2002, which started on October 1st. The new Continuing Resolution will run through October 31. Census Advisory Committee meetings: The Decennial Census Advisory Committee will meet on November 5 - 6, and the five Race and Ethnic Advisory Committees will meet on November 7 - 9, to discuss Census 2000 evaluations (including the ESCAP's work), planning for the 2010 census, the status of the American Community Survey, the findings of the National Academy of Sciences' Panel to Review the 2000 Census, the expanded Census Information Center program, and other relevant issues. Both meetings will take place at the Hilton Alexandria Mark Center Hotel, 5000 Seminary Road, Alexandria, VA (703-845-1010). The sessions are open to the public. New Census 2000 evaluations: The U.S. General Accounting Office, the audit and investigative arm of Congress, has issued two evaluations of Census 2000 operations and management. The reports, "2000 Census: Review of Partnership Program Highlights Best Practices for Future Operations (GAO-01-579, Aug. 20, 2001)" and "2000 Census: Better Productivity Data Needed for Future Planning and Budgeting (GAO-02-4, Oct. 4, 2001)," are available through GAO's web site at www.gao.gov <http://www.gao.gov> or by calling 202-512-6000 (TDD/202-512-2537). Questions about the information contained in this News Alert may be directed to Terri Ann Lowenthal at 202/484-2270 or, by e-mail at <mailto:terriann2k(a)aol.com>. For copies of previous News Alerts and other information, use our web site www.census2000.org <http://www.census2000.org>. Please direct all requests to receive News Alerts, and all changes in address/phone/fax/e-mail, to the Census 2000 Initiative at <mailto:Census2000(a)ccmc.org> or 202/326-8700. Please feel free to circulate this information to colleagues and other interested individuals.

23 years, 9 months

[CTPP] TAZ

by Michael Moan

Nanda, what are the implications for my CTPP package if the Census Bureau changed, added and split RI's census tracks? Our TAZ's are based on tracks and block groups. Michael Moan, RI Statewide Planning (MPO).

23 years, 10 months

[CTPP] c2ss data

by ed christopher

Recently, Elaine Murakami, FHWA and Nanda Srinivasan, Cambridge Systematics Inc., developed a transportation focused power point presentation using the C2SS data. They have passed the presentation along and it is now posted on the TRB Subcommittee on Census Data Webpage. http://www.TRBcensus.com/c2ss.html In addition to the powerpoint presentation are some "dot" points that several of us developed when the C2SS data first came out in August. The C2SS was a survey of 700K households designed to test the operational feasibility of collecting long form-type data simultaneously, but separately, from a decennial census. The first wave of C2SS data was released at the statewide level in August 2001. Additional data for most cities and counties of 250,000 or more people are scheduled for release in the fall 2001, and winter 2002.

23 years, 10 months

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

CTPP