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CTPP using ACS 2006-2010 (5-YEAR Summary)

README - Census Transportation Planning Products (CTPP)

This information was superseded in May 2013.

This Excel workbook contains the specifications for the Census Transportation Planning Products (CTPP) special tabulation using 5-year data.

DATA: The tabulation should be processed using the ACS 2006-2010 dataset.

A brief description of the tabs in this workbook:

"Geog" defines all geographies to be used with which tables.

"Universes" defines all universes to be used with the tables.

"Variables" defines all variables that are referenced in the tables lists.

"Tabs-Part1"defines residence geography tables, variables, universes, number of cells, and table numbering (Columns E-I). Table numbers can be prefixed with "T".

"Tabs-Part2" defines workplace geography tables, variables, universes, number of cells, and table numbering (Columns E-I). Except where noted, the universes include workers who worked at home (for whom workplace geocode is the same as the residence geocode). Table numbers can be prefixed with "T".

"Tabs-Part3" defines residence to workplace flow geography tables, variables, universes, number of cells, and table numbering (Columns E-I). Except where noted, the universes include workers who worked at home (who reside and work in the same geocode). Table numbers can be prefixed with "T".

FILE FORMAT requirements:

Standard Errors: The tabulation should include the standard errors (SEs) in addition to the 90% margins of error (MOEs). In other words, for each cell, please include the estimate, the 90% MOE, and the standard error. The standard error should be provided to 2 decimal places more than the relevant estimate. Please include this in the cost estimate.

Guidance: AASHTO requests that the Census Bureau provide guidance and special instructions, if any, on the recalculation of margins of error for aggregations of geographic units, variable categories, or different levels of statistical significance.

Output file number format: Please remove the "+/-" from the MOEs and also make all numbers (estimates, MOEs, and SE s) in numeric form in the output file.

Specific file structure, sequence of numbers, and format to be determined. File structure must accommodate numeric format and no "+/-". We understand that .CSV and SAS dataset file formats can be provided automatically. Please add a time and cost estimate for the Summary File ASCII files option (3 separate tables for each of estimates, SEs, and MOEs).

For the DRB- Changes since the 2008 CTPP table submission:

Variables Crosstabulated with Means of Transportation:

The number of variables crossed with Means of Transportation have been reduced to 8 across all three geographic levels. The eight variables are: presence of children, number of workers in households, minority status, travel time, household income, vehicle availability, age, and time leaving home (residence geography)/ time arriving at work (workplace geography). Note that Time Arriving at Work at workplace geography is a simple transformation of Time Leaving Home at residence geography and therefore is not a distinct variable.

In contrast, the 2008 submission had 18 crosstab variables for residence geography, 17 crosstab variables for workplace geography, and 6 crosstab variables for home-to-work flows.

The Set B tables contain several collapsed tables: 12201C, 12201C2 and 12201C3, for example. The collapsed versions of tables will be generated from the same perturbed microdata.

There is reference to "Large Geography Only" for some of the tables. Large geography means county, PUMA, and state.

Updated: 05/14/2013
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