README for “Principal Ports 2013-Present” dataset. U.S. Department of Defense (DOD), United States Army Corp of Engineers (USACE); U.S. Department of Transportation (USDOT), Bureau of Transportation Statistics (BTS) [distributor] 2025-05-29 ---------------------------------------------------------------- LINKS TO DATASET ---------------------------------------------------------------- A. Dataset archive link: https://doi.org/10.21949/1520847 B. NTAD catalog dataset link (Current Year): https://doi.org/10.21949/1522248 ---------------------------------------------------------------- SUMMARY OF DATASET ---------------------------------------------------------------- The Principal Ports 2013-Present dataset, formerly known as Major Ports, is from the United States Army Corp of Engineers (USACE), and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics’s (BTS's) National Transportation Atlas Database (NTAD). The ports are defined by port limits or Corps projects. The determination for the published Principal Ports is based upon the total tonnage for the port for the particular year, therefore the top 150 list can vary from year to year. The Principal Port file contains USACE port codes, geographic locations, names, and commodity tonnage summaries (total tons, domestic, foreign, imports and exports) for Principal USACE Ports. ---------------------------------------------------------------- TABLE OF CONTENTS ---------------------------------------------------------------- A. General Information B. Sharing/Access & Policies Information C. Data and Related File Overview D. Methodological Information E. Data-Specific Information for: Principal Ports 2013-Present [datasets] F. Update Log ---------------------------------------------------------------- A. GENERAL INFORMATION ---------------------------------------------------------------- 0. Title of Dataset: Principal Ports 2013-Present [dataset] 1. Description of Dataset: The Principal Ports 2013-Present dataset, formerly known as Major Ports, is from the United States Army Corp of Engineers (USACE), and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics’ (BTS's) National Transportation Atlas Database (NTAD). The ports are defined by port limits or Corps projects. The determination for the published Principal Ports is based upon the total tonnage for the port for the particular year, therefore the top 150 list can vary from year to year. The Principal Port file contains USACE port codes, geographic locations, names, and commodity tonnage summaries (total tons, domestic, foreign, imports and exports) for Principal USACE Ports. 2. Dataset archive link: https://doi.org/10.21949/1520847 3. Authorship Information: Principal Data Creator or Data Manager Contact Information Institution: U.S. Department of Defense (DOD), United States Army Corp of Engineers (USACE) Address: 7701 Telegraph Rd, Alexandria VA 22315 Contact: WSD-REACHBACK@usace.army.mil Data Distributor Contact Information Name: National Transportation Atlas Database (NTAD) Institution: U.S. Department of Transportation (USDOT), Bureau of Transportation Statistics (BTS), Office of Spatial Analysis and Visualization (OSAV) Address: 1200 New Jersey Ave. SE, Washington D.C. 20590 Email: ntad@dot.gov 4. Date of data collection and update interval: It is unknown if this dataset will be updated. 5. Geographic location of data collection: United States of America 6. Information about funding sources that supported the collection of the data: United States Army Corp of Engineers (USACE), U.S. Department of Defense (DOD) ---------------------------------------------------------------- B. SHARING/ACCESS & POLICIES INFORMATION ---------------------------------------------------------------- 0. Recommended citation for the data: U.S. Department of Defense (DOD), United States Army Corp of Engineers (USACE), U.S. Department of Transportation, Bureau of Transportation Statistics (BTS) [distributor]. Principal Ports 2013-Present [datasets]. https://doi.org/10.21949/1520847 1. Licenses/restrictions placed on the data: These data are in the Public Domain. 2. Was data derived from another source?: No. 3.This document was created to meet the requirements enumerated in the U.S. Department of Transportation's 'Plan to Increase Public Access to the Results of Federally-Funded Scientific Research' Version 1.1 << https://doi.org/10.21949/1520559 >> and guidelines suggested by the DOT Public Access website << https://doi.org/10.21949/1503647 >>, in effect and current as of December 03, 2020. ---------------------------------------------------------------- C. DATA & RELATED FILE OVERVIEW ---------------------------------------------------------------- 1. File List for the Principal Ports 2013-Present dataset A. Filename: Principal_Ports_NTAD2013_Present.zip Short description: Compressed file folders containing the geospatial data for Principal Ports 2013-Present dataset. File folders are classified by NTAD publication year and data vintage year or date respectively. B. Filename: bts_NTAD_Principal_Ports_DMP_20250529.pdf Short description: A PDF file containing the Data Management Plan that was created for current and future management of the data and associated files. C. Filename: bts_NTAD_Principal_Ports_README_20250529.txt Short description: The README.txt file that includes human-readable information about the data, variable definitions, contact information, and other contextual information. The file you are reading now. 2. File List for the Principal_Ports_NTAD2013_Present.zip collection. A. Filename: NTADXXXX_SHP_Final_Major_Ports_XXXX*.zip, NTADXXXX_GDB_Final_Major_Ports_XXXX_XX_XX, or NTADXXXX_GDB_Final_Principal_Ports_XXXX*.zip Short description: Compressed file folders containing the geospatial data for Principal Ports 2013-Present dataset. File folders are classified by NTAD publication year and data vintage year respectively. 3a. File List for the NTADXXXX_SHP_Final_Principal_Ports_XXXX*.zip collection. A. Filename: ports_major.shp or MajorPorts*.shp Short description: A shapefile containing the geospatial data for Principal Ports 2013-Present dataset. This includes associated files with extensions .prj, .dbf, .sbn, .sbx, .shx. B. Filename: ports_major.txt and ports_major.shp.xml, or MajorPorts*.shp.xml Short description: Text files containing key metadata and documentation information such as methodology, procedures, data dictionary, etc. 3b. File List for the NTADXXXX_GDB_Final_Major_Ports_XXXX_XX_XX, or NTADXXXX_GDB_Final_Principal_Ports_XXXX*.zip collections A. Filename: NTADXXXX_GDB_Final_Major_Ports_XXXX*.gdb.zip or NTADXXXX_GDB_Final_Principal_Ports_XXXX*.gdb.zip Short description: A file geodatabase containing the geospatial data for Principal Ports 2013-Present dataset. Geodatabase (GDB) folders contain all the necessary components to view and otherwise interact with their data. B. Filename: Principal_Ports.xml Short description: Text files containing key metadata and documentation information such as methodology, procedures, etc. C. Filename: Major Ports.xlsx or Principal_Ports.xlsx Short description: Excel spreadsheet containing the dataset's data dictionary. ---------------------------------------------------------------- D. METHODOLOGICAL INFORMATION ---------------------------------------------------------------- 1. Description of methods used for collection/generation of data: Merging of inland and offshore ports_major networks. A specialized program was written to merge the two networks. In general, Vanderbilt node locations were accepted as authoritative when both data sets had the same elements. This meant moving an Oak Ridge link incident to that node. If the link was classified geographically ocean or Great Lakes, and a Vanderbilt link or chain existed with the same ID and endpoints, the Oak Ridge link was discarded, after transfer of Oak Ridge attributes. If the Oak Ridge link was within 2 km of the new end nodes' location: and 1) if a duplicate Vanderbilt link existed with a higher source code, it replaced the Oak Ridge link, or 2) the Oak Ridge link was moved by a logistic adjustment to the new location. (This causes modest disruption to the preponderance of the shape, yet assured that the angle of approach to the displaced end node location was preserved.) If the link was functionally classed "deep draft" and a duplicate Vanderbilt link had an authoritative source code, the Oak Ridge link was replaced. Otherwise an additional shape point was added at the end to snap to the new node location without disrupting the original link shape. If the link had a Vanderbilt duplicate with the same ID, the Oak Ridge link was so flagged to be manually resolved. The composite network was then cleaned manually, resolving all cases of still remaining duplicate links and deciding case-by-case how to smooth or otherwise accommodate a highly displaced Oak Ridge shape into the Vanderbilt digitized node location, using TIGER shorelines as a background. 2. Instrument- or software-specific information needed to interpret the data: The data and documentation files can be opened with Esri ArcMap and any GIS software package. ---------------------------------------------------------------- E. DATA-SPECIFIC INFORMATION ---------------------------------------------------------------- 1. Principal Ports data table It is unknown if this dataset will be updated. Dataset Manager is contacted to verify changes to data resulting in NTAD update. The metadata is updated in the same manner. For the most recent data, please visit the NTAD catalog at https://doi.org/10.21949/1522248 A. Number of variables (columns): The data dictionary found in (PDF documentation) provides definitions for the variables B. Data Dictionary/Variable List: Because of the large number of variables, please refer to the Data Dictionary found within the file Principal_Ports.txt for names, definitions, and formats of variables. C. Missing data codes: None ---------------------------------------------------------------- F. UPDATE LOG ---------------------------------------------------------------- This bts_Principal_Ports_20250529_README.txt file was originally created on 2021-04-12 by Dominic Menegus, Geographer, dominic.menegus@dot.gov [Note changes or update to the readme.txt file, e.g.:] 2021-04-12: Original file created 2025-05-29: Revised document, including data descriptions and file organization.