US speeding study shows minimal time gain

A July 2026 analysis of 120 million U.S. vehicle trips found that speeding adds only about 54 seconds to a driver’s daily commute but costs the nation tens of millions of dollars in fuel each day. Researchers estimated that strict adherence to posted speed limits could save roughly $22‑$26 million, 6.7‑7.2 million gallons of gasoline and about 57,000 metric tonnes of CO₂ daily – an impact comparable to removing 5.5 million passenger vehicles from the road. The study noted that 43 % of trips included at least one speeding episode, with higher prevalence in Nevada, Florida, Georgia and North Carolina. A follow‑up report a week later refined these figures, finding that speeding accounts for about 11.7 % of travel time. Simulating a no‑speeding scenario predicts a 2.4‑3 % reduction in fuel use, equivalent to roughly 70 liters saved per vehicle per year, about 25 million liters per day across the light‑vehicle fleet, and over 9 billion liters annually. Daily CO₂ emissions would drop by the same 57,000 tonnes, surpassing 20 million tonnes per year, while monetary savings would reach about $22 million per day. Both reports stress that the time penalty for obeying limits is minimal—adding less than a minute to the average daily travel time—making slower driving a low‑cost measure to improve fuel efficiency and cut greenhouse‑gas emissions. On 26 July 2026, a University of Minnesota re‑analysis reaffirmed the earlier results, reporting that 43.2 % of U.S. trips exceed speed limits by an average of 11 mph, and that a no‑speeding scenario still saves only 54 seconds on a typical 46‑km daily trip. The commentary underscored that the modest time saving offers no real benefit while higher fuel consumption, emissions and accident risk increase costs.