The tables currently found in the ACS have been sufficient for my needs and concerns. The
idea expressed by Nathan is intriguing (if I understand it correctly); by "multiple
geographic units", do we mean various MCDs, TAZs or the 20,000 population areas?
Concerning the "Journey to Work Trends", I made use of that data primarily as
comparative analysis for the Twin Cities region to other MSAs and as a template for a more
detailed look at Minneapolis-St.Paul. However, given the workload that appears to exists,
I don't believe that updating the report to include the 2005-07 information would be
useful enough to spend additional time and resources ....at least for my specific needs
From: ctpp-news-bounces(a)chrispy.net [mailto:firstname.lastname@example.org] On Behalf Of
Sent: Wednesday, October 01, 2008 4:18 PM
Subject: [CTPP] Need your thoughts on CTPP products using ACS standard tables
Hi Everyone -
I bet you have a lot of questions about CTPP using the first 3 years of ACS and TAZs, but
unfortunately, I can't answer them yet!
Given the current uncertainty of the next CTPP ("custom tabulation") using the
ACS, we are moving forward to develop products using standard ACS products. Some of you
will recall that we created a series using the first 2005 ACS data products. They are
posted on both the FHWA web http://www.fhwa.dot.gov/planning/census/2005tpoverview.htm
and on the AASHTO web
On December 9, 2008, the Census Bureau plans to release the first 3-year ACS products
(surveys completed in 2005, 2006 and 2007). The minimum population threshold is 20,000
for the 3-year products, compared to 65,000 population for the ACS 1-year products. So,
while the data is still "swiss cheese," that is, geographic coverage has holes,
a lot more geographic units will be available. The results are still subject to the
Census Bureau rules of "collapsing and filtering" which means that sometimes the
data have been suppressed and you will see an "N".
We are now designing new profile sheets, in which we plan to include data from 2000 (using
Census Summary File 3 and CTPP2000) and from 2005-2007 ACS. Please let me know if you
have any recommendations for specific tables to include (the data must be available in
both 2000 and from the 2005-2007 ACS). One recommendation from Nathan Erlbaum (NYS DOT)
is to create a spreadsheet macro that will sum up multiple geographic units and
re-calculate the Margin of Error (using the materials on Page 96-98 in NCHRP Report 588).
Also, I am wondering if there is any interest in an updated "Journey to Work
Trends" report to include the 2005-2007 ACS results.
This report was limited to metropolitan areas
with population over 1 million, but had trend data including 1960, 1980, 1990 and 2000.
Because of redefinitions of metropolitan areas by OMB, the data need to be accumulated
from county records for historical comparability, which makes for quite a bit of work.
The last report used the 1999 definition, but the 2005-2007 ACS data will be reported
using the 2007 OMB definitions (I think). My question for you is: is this report useful
enough to spend time and resources on?
Thanks in advance for your opinions.
FHWA Office of Planning (Wash DC)
206-220-4460 (in Seattle)