New Study Shows Freight Rail Fuel Efficiency Up More Than 20 Percent Since 1999
The
Federal Railroad Administration (FRA) released a study showing
vast improvements in freight rail fuel efficiency over the last two
decades, approximately 22 percent between 1990 and 2006.
Trends in rail and truck fuel efficiency include:
Locomotive: Improvements include locomotive technology improvements, fleet composition, non-locomotive technology improvements, operational and train control improvements, as well as impediments to the implementation of fuel-saving actions.
Trucks: Improvements include truck engine improvements and the effects of emission regulations, non-engine technology improvements and changes in fleet composition, operational improvements, and impediments to the implementation of fuel-saving actions.
"While all types of transportation are vital to the distribution of goods across the country, this study shows that utilizing America's freight rail system can lead to significant fuel savings," said FRA Administrator Joseph Szabo. "The environmental benefits of these positive changes over the last two decades are enormous. We look forward to working with the freight rail industry to make sure these gains continue."
Several factors point to the reasons
for rail's fuel efficiency, including the improvement in
diesel-electric locomotives, the increased use of double stack trains,
track and signal improvements, and longer trains.
Finding 1: Rail is more fuel efficient than truck on all 23 movements.
For all movements, rail fuel efficiency is higher than truck fuel efficiency in terms of ton-miles per gallon. The ratio between rail and truck fuel efficiency indicates how much more fuel efficient rail is in comparison to trucks. As illustrated in Exhibit 1-1, rail fuel efficiency varies from 156 to 512 ton-miles per gallon, truck fuel efficiency ranges from 68 to 133 ton-miles per gallon, and rail-truck fuel efficiency ratios range from 1.9 to 5.5.
Finding 2: Double-stack trains and dry van trailers are the predominant equipment types in this study.
Double-stack trains account for 11 out of 23 rail movements, while dry van trailers are the equipment of choice for 12 truck movements. Double-stack service has become more predominant in the past two decades due to their fast and reliable transit times, while 53-foot dry vans provide large capacity while utilizing tractor aerodynamic aids that reduce fuel consumption.
Finding 3: There is a strong correlation between rail-truck fuel efficiency ratio and equipment type.
The tank car movement resulted in the highest ratio, followed by double-stack, covered hopper, and gondola movements. Auto rack movements resulted in the lowest ratios. The wide variation in rail-truck fuel efficiency ratios in double-stack movements is a result of the higher number of double-stack movements considered in this study.
Finding 4: The range of rail fuel efficiency is wider than the range of truck fuel efficiency.
Rail fuel efficiency has a much wider range, varying from 156 to 512 ton-miles/gallon, while truck fuel efficiency ranges from 68 to 133 ton-miles/gallon.
Finding 5: The variation in rail fuel efficiency is narrower if analyzed in terms of trailing ton-miles per gallon.
Rail fuel efficiency can be measured at the train level in trailing ton-miles per gallon. Double-stack trains tend to be more fuel efficient than other types of trains, despite their higher average speeds and poorer aerodynamic performance. The fact that intermodal operations do not require subsequent switching operations to classify rail cars contributes to the better performance of double-stack trains. The wide variation in fuel efficiency of double-stack and mixed trains as opposed to auto and TOFC trains is justified by the smaller number of movements analyzed in the latter trains.
Finding 6: Route circuity plays a role in the total fuel consumption and fuel efficiency associated with rail and truck movements.
Typically, distances by rail are greater than those over the road, but truck distance was longer in some movements due to the fact that truck routing minimized travel time rather than travel distance. In this study, truck routes are shorter in 17 out of 23 movements. Because the comparisons of rail and truck fuel efficiency reflect ton-miles per gallon, circuity is not taken into account, and consequently the fuel savings from using rail versus truck are not proportional to the ratio between rail and truck fuel efficiency. Rail resulted in fuel savings for all remaining movements, ranging from 18 to 1,108 gallons per carload.
Finding 7: Short branchline movements, switching operations, truck drayage, terminal operations and truck idling have very different impacts depending on the movement analyzed.
While truck idling accounts for less than 7% of total truck fuel consumption, short branchline movements, switching operations, truck drayage, and terminal operations represent a more sizeable share of total rail fuel consumption. Truck drayage and intermodal terminal operations account for 7-27% of total fuel consumed by intermodal trains, with the wide range justified by the fact that the analysis assumed a fixed distance for all drayage movements independently of the route distance. Therefore, the fuel share allocated to truck drayage was higher for shorter routes and lower for longer routes. Similar conclusions can be drawn for short branchline movements and yard switching operations, which combined make up 6-45% of fuel consumed by mixed trains.
Finding 8: Fuel savings from using rail can be significant.
Rail results in fuel savings when compared to their counterpart truck movement, ranging from 18 to 1,108 gallons per carload. Fuel savings can also be analyzed at the train level. For example, if trucks were to carry the equivalent payload included in the double-stack rail movements, fuel savings would evidently be much greater, varying from 1,549 to over 80,000 gallons per double-stack train.
Finding 9: The effects of empty mileage associated with rail and truck movements can be significant.
This study concludes that all intermodal movements (double-stack and TOFC) and gondola movements are even more fuel efficient than comparable truck movements when accounting for empty miles. In the case of box cars and covered hopper movements, the opposite is true. In those cases, rail is still more fuel efficient than trucks, but the gap between rail and truck narrows with the inclusion of empty miles. This analysis is inconclusive for auto movements.
The complete study can be found at: http://www.fra.dot.gov/Downloads/Comparative_Evaluation_Rail_Truck_Fuel_Efficiency.pdf.