Source: U.S. Army Corp of Engineers, Waterborne Commerce of the United States (government).
The Transportation Services Index (TSI) relies on ton and ton-mile data on inland waterborne trade from the U.S. Army Corps of Engineers (USACE). USACEs Waterborne Commerce of the United States (WCUS) Part 5 provides statistics on the foreign and domestic waterborne commerce on U.S. waters. WCUS, Parts 14 present detailed data on the movements of vessels and commodities at ports and harbors and on the waterways and canals of the United States and its territories.
Waterborne traffic movements are reported to the USACE by all vessel operators of record on ENG Forms 3925 and 3925b (or equivalent) approved by the Office of Management and Budget under the Paperwork Reduction Act (44 U.S.C. 3510(a)). The reports are generally submitted on the basis of individual vessel movements completed. For movements with cargo, points of loading and unloading of each individual commodity must be delineated. Cargo moved for military agencies in commercial vessels is reported as ordinary commercial cargo; military cargo movements in Department of Defense (DOD) vessels are not collected. In summarizing domestic commerce, certain movements are excluded: cargo carried on general ferries; fuel products, such as coal and petroleum, loaded from shore facilities directly into vessel bunkers; and insignificant amounts for government materials (less than 100 tons moved on government-owned equipment in support of USACE projects).
USACEs legal authority for the collection, compilation, and publication of waterborne commerce statistics is Section 11 of the Rivers and Harbors Appropriations Act of 1922 (42 Stat. 1043), as amended, and codified in 33 U.S.C. 555. Section 11 states that:
Individuals and corporations engaged in transporting their own goods on the navigable waters of the United States must report data related to vessels, passengers, freight, and tonnage as may be required by the Secretary of the Army.
Data Quality Questions
Insofar as all vessel operators must report waterborne traffic movements to the USACE, these data are a census. Only military cargo transported on DOD vessels are not reported.
- Is this data source a frame or sample?
Data source is a frame.
- Does the sample cover the entire frame? Or is some group missing or underrepresented in the sample? For the excluded group, what percentage of the total do they make up?
Cargo moved for the military agencies in commercial vessels is reported as ordinary commercial cargo; data on military cargo moved in DOD vessels are not collected. Beginning in 1996, fish landing data were excluded from internal and intraport domestic traffic data.
- Are the data available monthly?
- How soon are the data available after the month is over?
Usually within one week (e.g., in the first week of July, data for June are available).
- Are the data easy to access and use?
Web site: http://www.iwr.usace.army.mil/ndc/wcsc.htm
- Are the microdata available for use?
The monthly tons/ton-miles for different commodities can be requested from the USACE.
- Are there duplicate records?
- Are there outliers in the data?
- Are data missing for individual records? If so, how are they identified?
- How accurate are the key data fields?
Tonnage figures are rounded to the nearest 1,000 tons, a zero represents less than 500 tons but more than zero. Dashes mean zero tons.
- Are variances available for this data source? If so, what method was used to calculate variances?
Variances are available from the USACE.
Are the data comparable over time within the data source? If not, can data be made to be comparable (e.g., combining two data series)?
The tonnage for years 1990 and later is comparable to tonnages in years prior to 1990.
- Is sufficient documentation available for the data source?
The document can be found in the Annual Waterborne Commerce of the United States (WCUS) Waterways and Harbors, Part 5, National Summaries.
- Data dictionary:
InlandVessel movements that take place solely on inland waterways geographically located within the boundaries of the continental United States, including Alaska.
- Detailed description of the methodology:
All vessel operators report the traffic movement to the USACE. The tonnage figures provided through the Waterborne Commerce of the United States represent short tons (2,000 pounds)
- Operational details:
Tonnage is rounded to the nearest million. A zero represents less than 500 tons but more than zero. Dashes mean zero tons.
- Estimation methods:
All vessel operators engaged in carrying cargoes on the U.S. waterways report waterborne traffic movements.
- Are other sources available for the same data?
- Who is the contact for the data source?
U.S. Army Corps of Engineers Waterborne Commerce Statistics Center, http://www.iwr.usace.army.mil/ndc/wcsc.htm.