Opinion: Intermodal Isn’t ‘Greener’ Than Trucks

By John Burton
Vice President, Transportation Sector
ACT Research

This Opinion piece appears in the Oct. 19 print edition of Transport Topics. Click here to subscribe today.

You can’t watch television these days without hearing some railroad company advertising the “green” benefits of moving freight from the road to rail. The most often heard is the claim by one major railroad that “one ton of freight can be moved 436 miles on one gallon of fuel.” Another large railroad boasts a 470-mile claim in its 2008 Annual Report.

At first glance, these numbers seem to indicate there is no way trucking can compete and intermodal has to be the future for our efforts to go green. However, it is important that we dig deeper and look at “environmentally friendly” from a broader perspective.

Besides, intermodal still requires trucks.

Railroads may claim that one gallon of fuel moves a ton 436 miles, but they don’t claim that a train delivers the load to its ultimate destination. The combined miles for an intermodal move are almost always more than a trucking move. Trucking usually takes the most direct route, while an intermodal move is constrained by defined intermodal ramps.

What’s more, drayage is usually required at both ends of the journey, adding truck miles to get the freight to market. For example, a truckload from Columbus, Ind., to Reno, Nev., will travel about 2,100 miles over the road. However, an intermodal move likely will travel 240 miles on the road to Chicago, 2,415 miles on rails to Stockton, Calif., and 155 miles on the road back to Reno — a 34% increase to 2,810 total miles.

Using the railroad’s own carbon calculation methodology, trucks produce 270% more carbon output. But using our real-world example, the carbon differential for the total move is only about 65% higher.

However, this still isn’t the whole story.

• Not every ton of freight is equal: Railroads handle numerous commodities that weigh substantially more than traditional items moving in longhaul truck lanes, e.g., coal, grain and aggregates. A carload of these commodities can weigh 90 to 100 tons, whereas a double-stacked intermodal load maxes out at about 40 tons. In calculating “greenness,” the railroads use “the average revenue ton-miles for [their] system” to calculate the carbon savings. While fuel consumption is correlated to weight, it isn’t a linear relationship. Lighter weight intermodal cars won’t generate the same efficiency benefits heavy coal cars generate. In fact, a 1991 Department of Transportation/ Federal Railroad Administration study often referenced as a source by rail carriers shows that double-stacked intermodal generally had efficiency in a range of 250 to 350 ton-miles per gallon. If we use a midpoint of 300 ton-miles per gallon, our previous example of Columbus, Ind., to Reno, Nev., now shows a difference of only 27%.

• Not all locomotives are equal: New trucks and new locomotives have made improvements in fuel efficiency and emissions from generation to generation. However, trucking can move the needle more quickly on overall improvement than railroads because longhaul trucks are replaced much more rapidly than rail locomotives. While the average tractor age of major publicly traded trucking companies is in the three- to five-year range, major railroads’ locomotives average 15 to 20 years old.

CSX states in its annual report that almost 50% of its locomotive fleet was manufactured before 1990. BNSF doesn’t provide a similar breakdown, but the average age of its locomotives is 15 years.

While truckers will be able to realize improved miles per gallon from the new selective catalytic reduction — or SCR — units relatively quickly, it will take almost a decade for improvements from new-generation locomotives to have a similar effect on rail fuel efficiency.

Last, it isn’t just about carbon. Trucking has dramatically less nitrogen oxides and particulate matter. When the new 2010 engines hit the road, trucking will have reduced NOx and PM emissions by 99% over the past 20 years. Most trucks on the road today are producing 80% to 85% less pollutants than trucks from 1990.

Trucking currently is using ultra-low-sulfur-diesel fuel, which has a maximum sulfur content of 15 parts per million of particulate matter, compared with the low-sulfur diesel used by the rail industry, which contains up to 500 ppm sulfur.

Even if you concede the fuel-to-tons relationship of 2.7-to-1, railroads put out 1,200% more PM than their trucking peers.

Railroad claims may be true as they apply to overall railroad performance, but they don’t tell the true story on rail intermodal versus trucking. Trucking has made substantially more progress reducing pollutants than have rails, and the true carbon footprint comparisons are much closer when all factors are included.

Truckers acknowledge that intermodal plays a significant role in our national transportation network, as evidenced by major motor carriers using it in the right lanes to bring down costs and improve efficiency. We also know that rail intermodal doesn’t have and won’t likely ever have the infrastructure to support a fraction of the freight trucks haul. If environmental stewardship is really a railroad objective, wouldn’t they want to support heavier gross vehicle weights for trucking? Think of all the carbon, NOx and PM reductions that would produce.

ACT Research, Columbus, Ind., is a provider of data analytics, forecasting and market intelligence for the commercial vehicle industry.