Figuring Congestion’s Impact on Fuel Consumption and Emissions

Figuring Congestion’s Impact on Fuel Consumption and Emissions

March 20, 2019
Highway traffic bottlenecks are raising fuel costs and hurting the environment, ATRI Finds.

A study released by the American Transportation Research Institute quantifies how improvements to our nation’s highway infrastructure can help conserve fuel and reduce emissions.

Nationally, congestion is estimated to have increased the trucking industry’s fuel consumption by 6.87 billion gallons in 2016; adding an additional $15.74 billion to its fuel bill, according to ATRI, the nonprofit research arm of American Trucking Associations.

“Fleets today consider not only their bottom line but also their environmental performance,” explains Mack Guest, president of LAD Truck Lines. “This case study highlights how investing in our nation’s infrastructure can serve the dual purpose of lowering transportation costs and air pollution.”

In this newly released analysis, ATRI estimated the fuel consumption and emissions impacts of congestion occurring at one of the worst traffic bottlenecks in the country – the interchange of I-285 and I-85 in Atlanta, known locally as “Spaghetti Junction.”

This interchange is a five-level stack of roads and overpasses, with additional ramps to accommodate traffic on four nearby side roads. It has 14 bridges, the highest rising to 90 feet, and handles about 300,000 vehicles a day.

The institute says the research combined ATRI’s unique truck GPS database it uses to determine vehicle speeds by time of day with daily trip counts collected by the Georgia Department of Transportation and emissions factors derived from the U.S. Environmental Protection Agency’s emissions model.

The study found that by increasing average vehicle speeds to 55 mph – which currently are as low as 14 mph during the weekday evening commute – it projects savings of 4.5 million gallons of fuel annually – savings which it notes will benefit both local commuters and trucking companies.

Beyond fuel savings, by getting vehicle speeds up to 55 mph, the institute estimates reductions in emissions would be 17% for fine particulate matter, 5.5% for smog-forming NOx emissions and 8% for carbon dioxide emissions.

ATRI says the report is the second case study published as part of its “Fixing the 12%” research initiative. ATRI previously found that 89% of the trucking industry’s congestion costs are generated from just 12% of Interstate miles. “Improving that 12% could positively impact the flow of people and good as well as the environment,” the institute points out.

“These reductions in fuel consumption and emissions illustrate the potential ancillary benefits which could be achieved by making road improvements which eliminate or reduce congestion at this interchange as well as others throughout the nation,” asserts Mike Tunnell, ATRI’s director of environmental research.

Nationwide Bottleneck Survey

In February, ATRI released its 2019 report on the top 10 worst traffic bottlenecks for freight hauling in the United States, where many of the same intersections show up year after year, including Atlanta’s Spaghetti Junction, which takes its place on the list at No. 2.

The complete ATRI Top 10 bottleneck list is:

  1. Fort Lee, NJ.
  2. Atlanta: I-285 at I-85 (North)
  3. Atlanta: I-75 at I-285 (North)
  4. Los Angeles: SR 60 at SR 57
  5. Houston: I-45 at I-69/US 59
  6. Cincinnati: I-71 at I-75
  7. Chicago: I-290 at I-90/I-94
  8. Nashville, Tenn., I-24/I-40 at I-440 (East)
  9. Atlanta: I-20 at I-285 (West)
  10. Los Angeles: I-710 at I-105

ATRI’s analysis found that truck speeds across the top 10 locations are estimated to have dropped by an average of nearly 9% year-over-year as congestion worsened along the nation’s busiest freight roadways.

These studies and others like them help reinforce the need for Congress to adopt a strong infrastructure program, freight advocates argue. “ATRI’s research shows us where the worst pain points are – but they are far from the only ones,” notes American Trucking Associations President Chris Spear.

“This report should be a wakeup call for elected leaders at all levels of government that we must act quickly to address our increasingly congested highway system,” he adds. “Without meaningful investment in our nation’s infrastructure, carriers will continue to endure billions of dollars in congestion-related costs – which results in a self-inflicted drag on our economy.”

Elaine Nessle, executive director of the Coalition for America’s Gateways and Trade Corridors (CAGTC), says, “For too many years, federal freight infrastructure investment has lagged while our population and national economy grow. This financial burden cannot be shouldered by states, localities and the private sector alone.”

The freight system in the U.S. moves 55 million tons of goods daily, worth more than $49 billion, according to CAGTC. That adds up to approximately 63 tons per person per year.

The U.S. population is expected to grow by another 70 million people as of 2045. Freight movement across all modes also is seen increasing by nearly 42% by 2040. “To capitalize on the growing U.S. consumer base, our infrastructure network must be up for the task,” Nessle says.

“Existing programs are oversubscribed and international trading partners are outpacing our investments at a rapid clip – increased funding dedicated to freight infrastructure is necessary in order for the U.S. to remain competitive in the world marketplace, the infrastructure network must be up for the task.”

About the Author

David Sparkman | founding editor

David Sparkman is founding editor of ACWI Advance (, the newsletter of the American Chain of Warehouses Inc. He also heads David Sparkman Consulting, a Washington D.C. area public relations and communications firm. Prior to these he was director of industry relations for the International Warehouse Logistics Association.  Sparkman has also been a freelance writer, specializing in logistics and freight transportation. He has served as vice president of communications for the American Moving and Storage Association, director of communications for the National Private Truck Council, and for two decades with American Trucking Associations on its weekly newspaper, Transport Topics.

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