To improve understanding of rail freight travel times, the Bureau of Transportation Statistics (BTS) calculated the average overall line-haul speeds for the rail freight industry using published rail industry operational performance data.
Each Class I railroad in the United States reports its average line-haul speed on a weekly basis. The average speed is the over-the-road train speed and does not include terminal dwell time, time for local pickup and delivery, and the time shipments spend in storage yards. BTS calculated the average overall line-haul speed by taking a weighted average (using freight car-miles) of the individual railroad average speeds.
Average terminal dwell time is also reported weekly by each Class I railroad. For the overall average terminal dwell time, BTS uses freight cars on line as weights to combine these individual railroad averages. Average terminal dwell time applies principally to merchandise trains. These trains, which represent about 60 percent of total freight train traffic, generally transport individual carload shipments that may be switched, assembled, or disassembled at a number of terminals the trains travel through on their way from origin to destination. Unit trains, which comprise about 40 percent of rail freight traffic, carry a single commodity from origin to destination without switching at intermediate terminals. Unit trains are not significantly affected by terminal dwell time. Data are only available to calculate an industry average beginning in the second quarter of 2004 because railroads reported average terminal times as of the fifth week of 2004.