Dear CTPP listserv members--
For those of you who also subscribe to TMIP listserv, you can delete this message! There
has been an interesting discussion on TMIP listserv comparing regional model results to
CTPP 2000 Part 2 (place of work) results, particularly on transit shares for HBW trips.
So far, comparisons from San Diego, Dallas-Ft. Worth, San Francisco Bay Area, and Atlanta
have been posted.
To view the TMIP archives, here is the link. See the topic "CTPP CBD Mode
Shares" in the June 2004 folder. http://listserv.tamu.edu/archives/tmip-l.html
You may also be interested in helping the TRB urban data committee (ABJ30) with their
"Downtown Profile" project. See "Commuting to Downtown" in the CTPP
Status Report, April 2004. http://www.fhwa.dot.gov/ctpp/sr0404.htm
As those of the us in the survey business like to say, "there is more than one data
source." Each source has its benefits and pitfalls. So, for transit shares to CBD,
other sources may include: on-board transit surveys, Automatic Passenger Count (APC)
counts, O/D estimated from fare machines (generally currently limited to subways) and
workplace surveys. One of the benefits of the Census data is the large sample size (1:6
households, nationwide in 2000) and high response rate. However, please remember that the
Census is a survey of PERSONS, not TRIPS! And the Census question is for "usual mode
used last week." Also, low income neighborhoods tend to have lower response rates
than in upper income neighborhoods, similar to other transportation surveys.
FHWA Office of Planning
206-220-4460 in Seattle