Is shipping freight by rail and water better for the environment?

October 11, 2018 by Cody Januszko, Carnegie Mellon University Department of Engineering and Public Policy

Transporting freight by road accounts for around seven percent of the world's total energy-related carbon dioxide emissions. Recognizing that heavy road freight is particularly hard to decarbonize, Carnegie Mellon University researchers have published a paper to review the ways that goods can be transported via alternate means, such as by rail or water, to reduce both emissions and energy use.

In a recent paper, Decarbonizing Intraregional Freight Systems with a Focus on Modal Shift, published in Environmental Research Letters, a team of Carnegie Mellon Engineering and Public Policy (EPP) researchers, led by EPP Ph.D. student Lynn Kaack, explore strategies for decarbonizing freight transportation and policies to encourage the shift. The team also included Wilton E. Scott Institute for Energy Innovation faculty affiliates Parth Vaishnav, M. Granger Morgan, and Inês Azevedo.

The paper assesses the opportunities and barriers to decarbonizing freight by using several different strategies: reducing the demand for freight, optimizing vehicle use and loading, increasing the efficiency of these vehicles, decreasing the carbon content of fuel used to transport freight and shifting freight to low carbon-intensity modes of transportation. The authors refer to this last strategy as a modal shift—the primary focus of their paper.

In it, they write, "We emphasize that the deep decarbonization of the freight sector can only be achieved by combining modal shift with multiple other strategies, such as energy efficiency, switching to fuels with low or net zero carbon emissions, and improving operational efficiency."

Not only is lowering the demand for freight transportation exceedingly difficult, the team states it is not even clear that doing so is desirable, since the transport of goods is linked to economic vitality. The transportation sector could reduce its emissions by routing and packing trucks more efficiently and training drivers in efficient driving techniques.

"In the U.S., railroads own their own tracks, so they have to build their own infrastructure," says Vaishnav, an assistant research professor in EPP. "Trucking uses public infrastructure, but does not bear the full cost of the damage heavy trucks do to roads and other infrastructure and indeed to the environment."

According to the article, rail and inland water are less carbon intensive than roads, but inland water may in some places produce more than rail and ocean shipping. Although many rail systems in the world are electrified, U.S. freight trains run on diesel. The team suggests lowering emissions further by electrifying our rail systems, although this is very costly. In a similar fashion, electric vehicles and electrified roadways could also decarbonize freight, although this is also expensive and the technologically is difficult to achieve.

To encourage transitions to these lower-carbon options, the team recommends that policymakers put in place incentives to discourage road freight through tolls and taxes, and should support the construction of intermodal terminals that allow for shipments to be kept on as long as possible, before being efficiently and reliably transferred to road for last-mile delivery.

"Freight transportation is responsible for a large share of ," says Kaack. "We urgently need a stronger political focus on decarbonizing freight."

Explore further: Driving down freight emissions

Related Stories

Driving down freight emissions

June 21, 2018

Researchers, working with leading supermarket chain Waitrose have developed a more aerodynamic trailer design for articulated vehicles – cutting fuel consumption and pollution by around 7 percent.

Path to zero emissions starts out easy, but gets steep

June 28, 2018

Carbon dioxide emissions from human activities must approach zero within several decades to avoid risking grave damage from the effects of climate change. This will require creativity and innovation, because some types of ...

Recommended for you

A damming trend

December 14, 2018

Hundreds of dams are being proposed for Mekong River basin in Southeast Asia. The negative social and environmental consequences—affecting everything from food security to the environment—greatly outweigh the positive ...

Data from Kilauea suggests the eruption was unprecedented

December 14, 2018

A very large team of researchers from multiple institutions in the U.S. has concluded that the Kilauea volcanic eruption that occurred over this past summer represented an unprecedented volcanic event. In their paper published ...

The long dry: global water supplies are shrinking

December 13, 2018

A global study has found a paradox: our water supplies are shrinking at the same time as climate change is generating more intense rain. And the culprit is the drying of soils, say researchers, pointing to a world where drought-like ...

Death near the shoreline, not life on land

December 13, 2018

Our understanding of when the very first animals started living on land is helped by identifying trace fossils—the tracks and trails left by ancient animals—in sedimentary rocks that were deposited on the continents.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.