From the Web site:
The general public may access several sections of ASPM.faa.gov without logging in.
ASPM: ASPM: Airport Analysis, City Pair Analysis and Taxi Time data will be available within 60 days after the end of the month; i.e., August data will be available no later than November 1.
ATADS: Data previously available in ATADS is now available in OPSNET.
OPSNET: Operations and Delay data for each month will be available on the 20th of the next month; i.e., August data will be available on September 20.
CountOps: CountOps has the same access and availability schedule as OPSNET.
TFMSC: TFMSC: Airport and Distributed OPSNET data for each month will be available within 31 days after the end of the month; i.e., September data will be available no later than November 1.
ASQP: Operations by Airport data will be available within 60 days after the end of the month; i.e., August data will be available no later than November 1.

VTrans is Virginia's statewide transportation plan. It is prepared for the Commonwealth Transportation Board (CTB) by the Office of Intermodal Planning and Investment (OIPI). VTrans produces nearly 100 data points that are used for various planning and decision-making purposes.

This story showcases data resources provided by Virginia Department of Rail and Public Transportation (DRPT).

The Bureau of Transportation Statistics (BTS), part of the Department of Transportation (DOT) is the preeminent source of statistics on commercial aviation, multimodal freight activity, and transportation economics, and provides context to decision makers and the public for understanding statistics on transportation. BTS assures the credibility of its products and services through rigorous analysis, transparent data quality, and independence from political influence. BTS promotes innovative methods of data collection, analysis, visualization, and dissemination to improve operational efficiency, to examine emerging topics, and to create relevant and timely information products that foster understanding of transportation and its transformational role in society. The Bureau’s National Transportation Library (NTL) is the permanent, publicly accessible home for research publications from throughout the transportation community; the gateway to all DOT data; and the help line for the Congress, researchers, and the public for information about transportation.

2008-2012 National Travel Mode to Work by Selected Commuting Characteristics. Contains estimates, percentages and margins of error. Data is at the country level.

Brian McKenzie, "Modes Less Traveled—Bicycling and Walking to Work in the United States: 2008–2012", U.S. Census Bureau, American Community Survey Reports, Issued May 2014, ACS-25. (Table 4)

Data accessed from: https://www2.census.gov/library/publications/2014/acs/acs-25.pdf

Washington Metropolitan Area Transit Authority provides the schedules and timetables for the metrobus.

2019 Virginia Census Counties and County Equivalents geospatial data

U.S. Census Bureau; TIGER/Line Shapefiles 2019
Data accessed from: https://www.census.gov/geographies/mapping-files/time-series/geo/tiger-line-file.2019.html

TIGER/Line Shapefiles do not include demographic data, but they do contain geographic entity codes (GEOIDs) that can be linked to the Census Bureau’s demographic data.

The Geographic Areas Reference Manual (GARM) describes in great detail the basic geographic entities the Census Bureau uses (https://www.census.gov/programs-surveys/geography/guidance/geographic-areas-reference-manual.html).

TIGER Data Products Guide (https://www.census.gov/programs-surveys/geography/guidance/tiger-data-products-guide.html)

2013-2021 Virginia Population by Means of Transportation to Work by Number of Vehicles Available by Census Tract. Contains estimates and margins of error.

U.S. Census Bureau; American Community Survey, American Community Survey 5-Year Estimates, Table B08141
Data accessed from: Census Bureau's API for American Community Survey (https://www.census.gov/data/developers/data-sets.html)

The United States Census Bureau's American Community Survey (ACS):
-What is the American Community Survey? (https://www.census.gov/programs-surveys/acs/about.html)
-Geography & ACS (https://www.census.gov/programs-surveys/acs/geography-acs.html)
-Technical Documentation (https://www.census.gov/programs-surveys/acs/technical-documentation.html)

Supporting documentation on code lists, subject definitions, data accuracy, and statistical testing can be found on the American Community Survey website in the Technical Documentation section. (https://www.census.gov/programs-surveys/acs/technical-documentation/code-lists.html)

Sample size and data quality measures (including coverage rates, allocation rates, and response rates) can be found on the American Community Survey website in the Methodology section. (https://www.census.gov/acs/www/methodology/sample_size_and_data_quality/)

Although the American Community Survey (ACS) produces population, demographic and housing unit estimates, it is the Census Bureau's Population Estimates Program that produces and disseminates the official estimates of the population for the nation, states, counties, cities, and towns and estimates of housing units for states and counties.

Data are based on a sample and are subject to sampling variability. The degree of uncertainty for an estimate arising from sampling variability is represented through the use of a margin of error. The value shown here is the 90 percent margin of error. The margin of error can be interpreted roughly as providing a 90 percent probability that the interval defined by the estimate minus the margin of error and the estimate plus the margin of error (the lower and upper confidence bounds) contains the true value. In addition to sampling variability, the ACS estimates are subject to nonsampling error (for a discussion of nonsampling variability, see ACS Technical Documentation https://www.census.gov/programs-surveys/acs/technical-documentation.html). The effect of nonsampling error is not represented in these tables.

"ATSDR’s Geospatial Research, Analysis & Services Program (GRASP) created Centers for Disease Control and Prevention Social Vulnerability Index (CDC SVI or simply SVI, hereafter) to help public health officials and emergency response planners identify and map the communities that will most likely need support before, during, and after a hazardous event.

SVI indicates the relative vulnerability of every U.S. Census tract. Census tracts are subdivisions of counties for which the Census collects statistical data. SVI ranks the tracts on 15 social factors, including unemployment, minority status, and disability, and further groups them into four related themes. Thus, each tract receives a ranking for each Census variable and for each of the four themes, as well as an overall ranking."

For more see https://www.atsdr.cdc.gov/placeandhealth/svi/documentation/SVI_documentation_2018.html