I am aware of three ways to construct nationwide tables from Census
2000. As Wendell points out, first, please be sure of which geography
you want: MSA/CMSA (Metropolitan Areas), Place (Closest to city
definitions), Urbanized areas, urban clusters etc. For any of these
areas, there are different, but easy methods to aggregate the data for
the nation.
Then, please be aware that public transportation may sometimes include
Taxicabs, and sometimes they may not. It is often best to add up the
disaggregate modes that are available in the manner you see fit for your
analysis (18 total categories in Census 2000)
1. If you have access to SAS software, you can obtain some of
these files from the Missouri State Data Center (SDC) at
http://mcdc2.missouri.edu/cgi-bin/uexplore?/pub/data/sf32000
2. American Factfinder is very useful in summarizing "geography
within geography", but the geographies are limited to 7,000 from their
website (so this should work for state, county, MSA, Urbanized area
geographies). AFF outputs are easy to understand and take the least
effort.
3. For place and tracts (which may number more than 7,000
geographies), the easiest I've found is to use the BTS Transtats
website:
http://www.transtats.bts.gov/Tables.asp?DB_ID=630&DB_Name=Census%20Trans
portation%20Planning%20Package%20%28CTPP%29%202000&DB_Short_Name=CTPP%20
2000
Place codes for Census 2000 may be found using the special product STP64
on the CTPP website. Please see attached.
http://www.fhwa.dot.gov/ctpp/stp/stp64.zip
Thank you
Nanda Srinivasan