University of Minnesota study finds speeding barely saves commute time

Motorists attempting to shave minutes off their daily travel by exceeding posted speed limits are likely wasting fuel and increasing harmful emissions while achieving negligible time savings, according to new research. Published Thursday, 16 July 2026, in the journal Communications Sustainability, the study from the University of Minnesota offers a stark assessment of driving habits at a moment when U.S. Consumers face heightened fuel costs and global energy market volatility.

The research, which analyzed 120 million vehicle trips across the United States, found that for an average daily commute of 28.6 miles, adhering to posted speed limits adds only 54 seconds to a driver’s time behind the wheel. The analysis focused on roads with speed limits of 45 mph and higher. Across the sample, more than 43% of trips involved at least one instance of speeding, with drivers spending nearly 12% of their total travel time above the legal limit.

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According to William Northrop, a mechanical engineering professor at the University of Minnesota and a co-author of the study, the trade-off is clear:

"If your goal is to shave one minute off your time, then you’ve got to drive fast. If your objective is to get to your destination safely and to save fuel, then you might drive slower than the speed limit."

William Northrop, mechanical engineering professor at the University of Minnesota, via Canon City Daily Record

Environmental and Economic Implications

The implications of moderating driving speeds extend to national resource consumption. Based on calculations accounting for current fuel prices and vehicle miles traveled, researchers estimate that American drivers could collectively save approximately $26 million and 7.2 million gallons of fuel each day by consistently observing speed limits. This reduction in fuel burn would eliminate 57,000 metric tonnes of carbon dioxide emissions daily, a figure researchers compared to removing 5.5 million passenger vehicles from the road.

While the study primarily addressed internal combustion engine vehicles, researchers also modeled data for battery-electric vehicles in California. We find that driving slower is beneficial for EVs as well, Northrop stated. Despite the potential for personal and environmental savings, Rob Middleton, an associate research scientist at the University of Michigan who was not involved in the study, noted that while the figures are large, they represent a small fraction of the 375 million gallons of gasoline consumed daily in the U.S. He described the practice of slowing down as a freebie that costs nothing to implement.

Context of Global Energy Volatility

This finding arrives as drivers face persistent pressure from the global energy market. The International Monetary Fund has recently cautioned that global oil buffers are depleting following conflict in the Middle East. With the war in Iran driving fuel costs higher, experts suggest that improved efficiency through behavioral changes—such as reducing speed—could influence market demand. Meanwhile, nations are scrambling to stabilize supply; for instance, South Korea has reported securing 74% of its anticipated crude oil needs for September despite ongoing tensions near the Strait of Hormuz.

Regional Variations in Driving Habits

The University of Minnesota study identified significant geographical disparities in how Americans drive:

• High Speeding Prevalence and Excess: Nevada displayed both frequent speeding and high levels of speed excess.
• High Prevalence, Low Excess: Florida, Georgia, and North Carolina showed frequent speeding, though not necessarily at extreme levels of excess.
• Low Prevalence and Excess: Montana, Wyoming, Idaho, and South Dakota exhibited the most consistent adherence to speed limits.

As the U.S. Continues to integrate more efficient vehicle technologies, researchers point out that the fundamental physics of drag and energy expenditure remain unchanged. While engine technology has improved over the decades, the decision to maintain high speeds continues to counteract these efficiency gains. Future studies may look to see how driver behavior shifts as the transition to electric vehicles continues to grow, though experts maintain that for the current fleet of conventional vehicles, the most immediate path to efficiency is a lighter touch on the accelerator.