The Mississippi River (north of St. Louis, MO) and its tributaries (e.g., the Arkansas River, Illinois River, Ohio River, etc.) make use of a series of locks and dams to bring traffic up and down the waterways. Grain generally flows south from the relatively production-rich areas of the Midwest to export ports in Louisiana and feed markets in the southeast.

This dataset provides weekly information on the amount (in tons), location, and commodity of barged grain transiting the following three major points: (1) the last lock on the Mississippi, Mississippi Locks 27 (called "Miss Locks 27" in the dataset), which captures downbound traffic from the Upper Mississippi and Missouri Rivers; (2) the last lock on the Ohio River, Olmsted Locks and Dam (called "Ohio Olmstead" in the dataset), which captures any downbound traffic on the Ohio and Tennessee Rivers; and (3) the last lock on the Arkansas River, Arkansas River Lock and Dam 1 (called "Ark Lock 1" in the dataset).

Ohio Olmsted locks replaced Ohio Locks 52 beginning in November 2018.

Commodities include "corn," "soybeans," "wheat," and "other" (oats, barley, sorghum, and rye).

Combined, these three locks give a sense of barge grain traffic (by commodity) on the Mississippi--since grain shipments heading south from the Upper Mississippi River, Illinois River, Ohio River, and Arkansas River are captured. Note, however, that this data does not include all grain barge movements on the Mississippi Rover System, as some grain originates on the Mississippi below the locking portion (south of St. Louis, MO). Grain traffic originating below Lock 27 on the Mississippi is about 10 to 30 percent of total downbound grain shipments, which varies year to year.

A similar dataset, "Upbound and Downbound Loaded and Empty Barge Movements (Count)," contains information on the count of grain barges moving down the locking system (https://agtransport.usda.gov/d/w6ip-grsn) versus this dataset that shows tonnages.

Data is collected weekly from the U.S. Army Corps of Engineers' Lock Performance Monitoring System.

Weekly train speeds data from the Surface Transportation Board's (STB) Rail Service Metrics. The STB began collecting service metrics from railroads in October 2014. As part of their submission to the STB, railroads provide data on the average speed of their trains (in miles per hour), broken out by commodity/type such as automotive, coal, crude oil, ethanol, grain, intermodal, manifest, etc. Railroads also report a “system average” train speed. According to the STB rulemaking, train speed should be measured for line-haul movements between terminals. The average speed for each train type should be calculated by dividing total train miles by total hours operated.