The States dataset was updated on October 31, 2023 from the United States Census Bureau (USCB) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). This resource is a member of a series. The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. States and equivalent entities are the primary governmental divisions of the United States. In addition to the fifty States, the Census Bureau treats the District of Columbia, Puerto Rico, and each of the Island Areas (American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, and the U.S. Virgin Islands) as the statistical equivalents of States for the purpose of data presentation.

The 2020 Adjusted Urban Areas dataset was compiled on December 31, 2020 from the Federal Highway Administration (FHWA) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). The 2020 Federal Highway Administration (FHWA) Adjusted Urban Areas layer delineates the boundaries of adjusted urban areas as defined by the FHWA, based on the 2020 U.S. Census urban area boundaries. This nationwide geospatial dataset represents urbanized areas that have been modified through coordination between FHWA Division Offices, State Departments of Transportation (DOTs), and Metropolitan Planning Organizations (MPOs), in accordance with FHWA's Urban Area Boundary Adjustment guidelines. These boundaries are used for transportation planning and programming, eligibility determinations, and analysis purposes related to Federal-aid highway programs. A data dictionary, or other source of attribute information, is accessible at https://doi.org/10.21949/1528364

The Federal Railroad Administration (FRA) Districts dataset was created on October 13, 2022 from the Federal Railroad Administration (FRA) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). District boundaries represent geographic divisions of safety disciplines. These are no longer used to represent administrative boundaries.

The National Highway System (NHS) dataset and its geometries was updated on May 01, 2024 from the Federal Highway Administration (FHWA) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). The National Highway System consists of roadways important to the nation’s economy, defense, and mobility. The National Highway System (NHS) includes the following subsystems of roadways: Interstate - The Eisenhower Interstate System of highways, Other Principal Arterials - highways in rural and urban areas which provide access between an arterial and a major port, airport, public transportation facility, or other intermodal transportation facility, Strategic Highway Network (STRAHNET) - a network of highways which are important to the United States’ strategic defense policy and which provide defense access, continuity and emergency capabilities for defense purposes, Major Strategic Highway Network Connectors - highways which provide access between major military installations and highways which are part of the Strategic Highway Network, Intermodal Connectors - highways providing access between major intermodal facilities and the other four subsystems making up the National Highway System. A specific highway route may be on more than one subsystem.

The National Network dataset is as of December 22, 2020 and is from the Bureau of Transportation Statistics (BTS) along with the Federal Highway Administration (FHWA), and part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). The National Network was authorized by the Surface Transportation Assistance Act of 1982 (P.L. 97-424) and specified in the U.S. Code of Federal Regulations (23 CFR 658) to require states to allow conventional combinations on "the Interstate System and those portions of the Federal-aid Primary System serving to link principal cities and densely developed portions of the states on high volume routes utilized extensively by large vehicles for interstate commerce which do not have any unusual characteristics causing current or anticipated safety problems. “The National Network (NN) includes almost all of the Interstate Highway System and other, specified non-Interstate highways. On March 31, 2025, four (4) records were updated to correct their "SIGNT1" and "SIGNN1" values. “The National Network (NN) includes almost all of the Interstate Highway System and other, specified non-Interstate highways. The network comprises more than 200,000 miles of highways. The National Network supports interstate commerce by regulating the size of trucks. This file is a geospatial representation of the National Network as described in 23 CFR 658 Appendix A and should not be interpreted as the official National Network and should not be used for truck size and weight enforcement purposes or for navigation. A data dictionary, or other source of attribute information, is accessible at https://doi.org/10.21949/1529045

The Time Zones dataset was compiled on October 04, 2019 and was updated January 05, 2023 from the Bureau of Transportation Statistics (BTS) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). This layer is a digital representation of the geographic boundaries of the nine time zones that cover the United States and its territories (the Atlantic, Eastern, Central, Mountain, Pacific, Alaska, Hawaii–Aleutian, Samoa, and Chamorro time zones). The U.S. Department of Transportation (DOT) oversees the Nation's time zones and the uniform observance of Daylight-Saving Time. The oversight of time zones was assigned to DOT due to the importance of time coordination for transportation related activities. The time zones were established by the Standard Time Act of 1918 and amended by the Uniform Time Act of 1966. Time zones in the U.S. are defined in the U.S. Code, Title 15, Chapter 6, Subchapter IX - Standard Time. The time zone boundaries are defined in the Code of Federal Regulations (CFR), Title 49, Subtitle A, Part 71 - Standard Time Zone Boundaries. Segments used to compile the geospatial layer were derived from the CFR’s time zone descriptions (https://www.ecfr.gov/current/title-49/subtitle-A/part-71). Descriptions consist of segments referencing administrative boundaries, infrastructure, natural features, and geodesic lines. These segments are contained in various data layers in the National Geospatial Data Asset (NGDA) portfolio, the federal government’s authoritative geospatial data repository. Referenced segments were extracted from their NGDA and then merged to form continuous boundaries. In instances where there were multiple scales for a given dataset, the largest scale or most detailed layer was used. The standard time of the Atlantic zone is the Coordinated Universal Time (UTC) minus 4 hours; Eastern zone is UTC minus 5 hours; Central zone is UTC minus 6 hours; Mountain zone is UTC minus 7 hours; Pacific zone is UTC minus 8 hours; Alaska zone is UTC minus 9 hours; Hawaii–Aleutian zone is UTC minus 10 hours; Samoa zone is UTC minus 11 hours; and Chamorro zone is UTC plus 10 hours. For more information, please visit: https://doi.org/10.21949/1519143.

The Federal Motor Carrier Safety Administration (FMCSA) Regions dataset is as of October 06, 2022 from the Federal Motor Carrier Safety Administration (FMCSA) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). This dataset is displayed as polygons depicting the regions covered by the four FMCSA Service Centers. More information on the FMCSA Service Centers, and territories each covers, can be found at: https://www.fmcsa.dot.gov/mission/field-offices

The Places dataset was published on August 31, 2022 from the United States Census Bureau (USCB) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). This resource is a member of a series. The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The TIGER/Line shapefiles include both incorporated places (legal entities) and census designated places or CDPs (statistical entities). An incorporated place is established to provide governmental functions for a concentration of people as opposed to a minor civil division (MCD), which generally is created to provide services or administer an area without regard, necessarily, to population. Places always nest within a state, but may extend across county and county subdivision boundaries. An incorporated place usually is a city, town, village, or borough, but can have other legal descriptions. CDPs are delineated for the decennial census as the statistical counterparts of incorporated places. CDPs are delineated to provide data for settled concentrations of population that are identifiable by name, but are not legally incorporated under the laws of the state in which they are located. The boundaries for CDPs often are defined in partnership with state, local, and/or tribal officials and usually coincide with visible features or the boundary of an adjacent incorporated place or another legal entity. CDP boundaries often change from one decennial census to the next with changes in the settlement pattern and development; a CDP with the same name as in an earlier census does not necessarily have the same boundary. The only population/housing size requirement for CDPs is that they must contain some housing and population. The boundaries of most incorporated places in this shapefile are as of January 1, 2022, as reported through the Census Bureau's Boundary and Annexation Survey (BAS). The boundaries of all CDPs were delineated as part of the Census Bureau's Participant Statistical Areas Program (PSAP) for the 2020 Census, but some CDPs were added or updated through the 2022 BAS as well.

The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line shapefile is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The All Roads Shapefile includes all features within the MTDB Super Class "Road/Path Features" distinguished where the MAF/TIGER Feature Classification Code (MTFCC) for the feature in MTDB that begins with "S". This includes all primary, secondary, local neighborhood, and rural roads, city streets, vehicular trails (4wd), ramps, service drives, alleys, parking lot roads, private roads for service vehicles (logging, oil fields, ranches, etc.), bike paths or trails, bridle/horse paths, walkways/pedestrian trails, and stairways.

The North American Rail Network (NARN) Rail Yards dataset was created in 2024 and was updated on October 16, 2024 from the Federal Railroad Administration (FRA) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). This Rail Yards layer represents and is derived from where the North American Rail Network (NARN) Lines layer as aggregated by type of track designated as yards. A rail yard is an area consisting of a network of tracks where trains are stored and/or maintained.The NARN Rail Lines dataset is a database that provides ownership, trackage rights, type, passenger, STRACNET, and geographic reference for North America's railway system at 1:24,000 or better within the United States. The data set covers all 50 States, the District of Columbia, Mexico, and Canada.