Effective October 1, 2005, the railroads began applying a new, standardized definitional framework to produce the performance data reported on this Web site, eliminating the differences resulting from the calculation methodology. Where possible, data back to January 1, 2005, have been restated on the new basis.

Despite the use of a common methodology, one railroad’s performance metrics cannot meaningfully be compared to another railroad’s, due to differences including, but not limited to, those associated with network terrain and design characteristics, traffic mix, traffic volume, length of haul, extent of passenger operations, and operational practices — as well as external factors such as weather and port operations which can impact carriers differently.