[CTPP] CTPP 3-year table request

[Ed Christopher]

Earlier this month the AASHTO CTPP Oversight Board submitted a request 
for a special tabulation of 3-year ACS tables.  For those who might not 
remember, just over a year ago the Oversight Board submitted a similar 
request that met with some harsh disclosure and suppression rules. 
After an appeal of the rules failed, the Oversight Board set up a 
subcommittee to develop a new request that hopefully would be more 
favorably received by the Census Bureau's Disclosure Review Board.  It 
was believed that now that the disclosure proofing rules are known it 
would be possible to design data tables that would yield the maximum 
utility possible while still adhering to the rules.

A copy of the new table request letter and tables can be found at the 
following locations respectively.
http://trbcensus.com/aashto/docs/CTPP_3-year_table_request.pdf
http://trbcensus.com/aashto/docs/CTPPtables-09apr01-1.xls

One of the major differences of the new request from last year’s is that 
modes used to go to work have been collapsed.  In 2008 we were asking 
for crosstabs using 5, 8 and 11 modes.  With the 2009 request we are 
asking for 3, 5, 6 and 10 modes.  In addition to the collapsed modes the 
number of variables crossed with “Means of Transportation to Work” has 
been reduced from about 17 to 5.  The 5 variables include travel time to 
work, household income, vehicles available, age and time leaving home to 
go to work.  Of course it will not be known which tables will pass the 
disclosure rules until we actually see the tables.  The is also none 
univariate table with all 18 modes.  When reviewing the potential tables 
do not forget that the 3-year ACS is only for areas with more than 
20,000 residents.

The Census Bureau and their Disclosure Review Board (DRB) are currently 
reviewing the proposal and the Oversight Board is hopeful that it will 
be approved.  Once the DRB is OK with the proposal it will pass over to 
the ACS Office and they will prepare a cost estimate after which a final 
decision by the Oversight Board will be made.

-- 
Ed Christopher
708-283-3534 (V)
708-574-8131 (cell)

FHWA RC-TST-PLN
19900 Governors Dr
Olympia Fields, IL 60461