Many industries in the U.S. have cut their carbon footprints in recent years, but transportation remains one sector where emissions are still rising. And in an effort to put the brakes on this trend, the Obama administration announced a set of new fuel-efficiency standardsĀ for heavy-duty trucks, vans and buses.
āThe main reason emissions are up in the transportation sector is due to increased emissions from medium and heavy-duty trucking,ā says Brandon Schoettle, the project manager for Sustainable Worldwide Transportation at theĀ University of Michigan Transportation Research Institute. āThat, of course, we think is mostly due to increases in the actual use of medium and heavy trucksāthings like construction, transporting goods and cargo around the United States.ā
LISTEN:Ā Making Our Truck Fleet More Fuel-Efficient
Schoettle says there has been a 30 percent increase in the number of light-duty vehicles on the road since 1990. And emissions fromĀ most other parts of the transportation sectorālike carsāhave stayed relatively flat during that time.
āVehicles have just been getting more efficient during that time,ā he says. āRecently,Ā weāve hit some records in terms of new vehicle fuel economyāespecially over the past 10 or 15 years. So those gainsāeven though weāve been also gaining quite a few vehiclesāhave led to a sort of stable performance in terms of emissions.ā

But Schoettle says reducing the collective carbon footprint of the countryās truck fleet could be tricky.
āFor cargo, itās a little different. They get what we would generally think of as pretty poor fuel economyāfive, six, seven miles per gallon. But, of course, theyāre hauling tens of thousands of pounds of cargo around. So theyāve been increasing their cargo efficiency significantly during the same period we looked at. But the increase in just cargo operations moving around the country has led to the increase.ā
Schoettle says his team is looking at ways to improve the fuel efficiency of heavy trucks. Their new study is due out later this summer.
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This story comes from our partners at Michigan Radio's Environment Report, a program exploring the relationship between the natural world and the everyday lives of people in Michigan.
