Driving faster than the posted speed limit saves drivers less than a minute per day on average, according to a study by University of Minnesota researchers published in the journal Communications Sustainability. The analysis of 120 million car trips across the U.S. in 2021 found that adhering to speed limits added only about 54 seconds to the average daily commute of 28.6 miles, equating to just over six minutes per week.
Despite these minimal time savings, a substantial portion of drivers frequently exceed speed limits. The study revealed that 43 percent of trips analyzed included at least one instance of speeding, and drivers spent approximately 12 percent of their time behind the wheel going faster than the posted limit. Professor William Northrop, a co-author of the study, stated that while modern vehicles are more powerful and capable of higher speeds, the benefits of driving fast are negligible compared to the consequences.
Beyond the negligible time gains, speeding leads to a notable increase in fuel consumption. The research indicates that speeders burn an additional 2.3 to 3 percent more gasoline on average. If all drivers complied with speed limits, it is estimated that the U.S. could save an average of $22 million and 6.7 million gallons of fuel annually. This suggests that the fuel cost of speeding far outweighs any time saved.
The environmental impact of speeding is also significant. The study estimates that light-duty, engine-powered vehicles waste approximately 7,000 metric tons of carbon dioxide every day by ignoring speed limits. This contributes to air pollution and accelerates the decline of the ozone layer. Researchers concluded that driving slower is a feasible intervention for substantial fuel savings and reduced emissions, achievable without the need for new vehicle technology.