This report provides a breakout by mode of corn, wheat, soybeans, sorghum, and barley movements to either domestic markets or U.S. ports for export between 1978 and 2020. It is the thirteenth update of an initial modal share study completed in 1992. The purpose of this series of reports is to provide the latest information about changes and trends in the relative competitiveness and efficiency among the different transportation modes in moving grain. Estimates of the tonnages (and shares) of grain railed, barged, and trucked are developed from a variety of secondary sources. This data can be used to identify trends and implications on transportation from factors, such as changes in production volumes and commodity mix, as well as changes in the relative demand for U.S. grain for domestic purposes versus export.