CTPP PROFILES (November 12, 2002)
The first data product of the Census Transportation Planning Package 2000
(CTPP2000) is now available. The Census Bureau has prepared profile sheets
for states and counties, which are posted on the American Association of
State Highway and Transportation Officials (AASHTO) web page at
in both html format and pdf format. The
html format can be read easily into a spreadsheet while the pdf format can
be printed easily. One convenience of these profile sheets is that they
include data from both 1990 and 2000 for some basic characteristics such as
household size, vehicle availability, means of transportation to work, and
travel time to work.
Notes about the data in the CTPP profiles:
1. GEOGRAPHIC LEVEL REPORTED: Data are limited in most cases to state
and county totals. In six states, (Connecticut, Maine, Massachusetts, New
Hampshire, Rhode Island, and Vermont) data for minor civil divisions (MCD)
are also included.
2. DATA ROUNDING: In CTPP 2000 and other special tabulations from
Census 2000, figures that do not duplicate data released in standard census
products are being rounded. Therefore, certain tables in the CTPP profile
sheets contain rounded numbers. In these tables values from 1 through 7
have been rounded to 4, and values greater than or equal to 8 have been
rounded to the nearest multiple of 5.
3. DATA SOURCE IS DECENNIAL CENSUS LONG FORM: All of the data in the
CTPP Profile are from the "long form." The data will not match the short
form (100% count) data exactly.
4. MICROSOFT EXCEL 97 PROBLEM: There is a display problem when the
CTPP2000 profiles in html format are opened in Microsoft Excel 97. The
problem is that the second column (column B) of the spreadsheet is hidden
from view. To display column B, right-click the mouse over either the
column A or column C header, and choose Unhide from the pop-up menu. This
problem appears to be corrected in later versions of Microsoft Excel.
5. MEANS OF TRANSPORTATION TO WORK: Public transportation includes bus
or trolley bus, streetcar or trolley car, subway or elevated, railroad,
ferryboat, and taxicab. In subsequent CTPP2000 tabulations, taxicab will
generally be included in the "other means" category. However, in the CTPP
profiles taxicab has been included in public transportation, similar to
aggregations used in the Census 2000 demographic profiles.
6. TRAVEL TIME TO WORK: In the 1990 Census (including the CTPP data),
the maximum travel time assigned to any worker was 99 minutes. Workers who
reported travel times of 100 minutes or more were top-coded to 99 minutes
in 1990. The maximum travel time was increased to 200 minutes for Census
2000, thus the 2000 data are more accurate because they include the actual
value for these long trips. The impact of this coding change is that
increases in travel time between 1990 and 2000 are somewhat over-stated.
At the national level, the Census Bureau estimates that about 29% (0.9
minutes) of the 3.1-minute increase in average travel time between 1990 and
2000 is attributable to the coding change.
7. HOUSEHOLD INCOME IN 1999: In a small number of cases, the mean
household income and median household income figures shown in the CTPP2000
profiles differ from those published in other Census 2000 products. These
differences of one dollar are the result of software rounding differences
and hardware numeric precision differences between the two platforms used
to create the products.
8. VEHICLES AVAILABLE: The data in CTPP2000 on vehicles available are
tabulated for households. This is different than in standard census
products, where data on vehicles available are tabulated for housing units.
Although the estimates are usually quite close, the number of housing units
is not always equal to the number of households, because the Census Bureau
calculates weights differently for housing units and households.
Therefore, the distribution of vehicles available shown in CTPP2000 will
not exactly match the distribution (or mean number of vehicles per
household) presented in standard census products from either 1990 or 2000.
For additional information about CTPP2000 products, please see