Grain shuttle trip data from the Surface Transportation Board's (STB) Rail Service Metrics. Each month, the railroads with dedicated grain shuttle service (BNSF, UP, and CP) provide information on the number of turns their grain shuttles make per month. Shuttle trips per month (TPM) should be reported on an average basis. For example, if a particular train set makes three origin to destination moves and another train set makes five origin to destination moves during the same calendar month, the railroad’s average TPM would be four.

The data applies only to those carriers operating grain unit trains in shuttle service. STB eliminated the requirement for carriers with (non-shuttle) dedicated grain trains to report trips per month "because the disparate data carriers could provide on that type of service would not provide the Board insight into service beyond the velocity data collected elsewhere." STB instructs, "in the first report of each month, railroads operating grain shuttles are required to report their average train trips per month for their system and key destination regions versus planned trips per month for their system and key regions for the previous month."

While STB collected related shuttle trip data as part of its initial collection in October 2014, those data included non-shuttle grain trains and, thus, are not directly comparable with the set beginning March 29, 2017.