Comparative Assessment of the Emissions Impacts of Surface Freight Transportation Modes (truck, rail, water, etc.)

Focus Area

Air Quality


Air Quality







Research Idea Scope

TERI Administrator Note (June 2007): Research Need Met
FHWA, Assessing the Effects of Freight Movement on Air Quality at the National and Regional Level, Final Report, April 2007

Given that rail and water transportation modes provide better fuel efficiency per ton-mile than highway vehicles, there is a need to understand the air quality impacts of the goods movement system as a whole and the emissions tradeoffs among the various surface transportation modes.

Researchers will:

1) evaluate the status of current emission regulations for each of the modes of transport and where each mode stands in its ability to meet those requirements;
2) identify improvements in emissions and activity estimation techniques for the three principal surface transportation modes, and
3) evaluate the emission rates for these modes and recommend changes to those rates if necessary.

The result of this research will include modal comparison for emissions of NOx, PM2.5, PM10, CO, CO2, SOx, VOCs, and toxic air contaminants. The next task will be to research existing systems and logistics models and recommend improvements to these models if necessary. The researchers shall identify opportunities to reduce emissions through effective modal mix.

Urgency and Payoff

There is a pressing need to develop a better understanding of the relative activity profiles and emissions from the three principal modes of transportation (highway, rail, and water), the interactions among these modes, their impacts on air quality, and methods for reducing those emissions. The rail industry accounts for 40% of the intercity freight transportation ton-miles, and rail operations consume over 4 billion gallons of diesel fuel per year. Marine vessels use the largest engines in transportation and the dirtiest fuel, with no significant emission regulations or controls. There has been very little research into rail and water emission control technologies and strategies, although emission regulations are now being implemented in the rail industry, and marine regulations are on the horizon. The on-road heavy-duty vehicle fleet has been studied for more than 20 years, but even the state of knowledge for this mode is inadequate.

Suggested By

Transportation Research Board 2002 Environmental Research Needs Conference Notes

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