A recent study published in the Nature journal Communications Sustainability found that driving at or below the posted speed limit can save U.S. drivers millions of dollars at the gas pump and eliminate millions of gallons of fuel each day.
The Study
University of Minnesota researchers analyzed 120 million vehicle trips across the United States from four Wednesdays in 2021 using driving data on national road networks, speed limits, and U.S. Geological Survey elevation data. The analysis included roads with speed limits of 45 mph and higher.
More than 43% of the studied trips included at least one instance of speeding, and drivers spent nearly 12% of their driving time going faster than the speed limit. The researchers found that if drivers of light-duty, conventional internal combustion engine vehicles actually drove at posted speed limits, it could save an average of $22 million, based on fuel costs at the time, 6.7 million gallons of fuel, and 57,000 metric tonnes of carbon dioxide every day.
Benefits of Safe Driving
The study also found that driving at or below the posted speed limit corresponds to only about 54 seconds longer per day, with an average daily driving distance of 28.6 miles. This suggests that the benefits of safe driving far outweigh the minimal time saved by speeding.
According to William Northrop, mechanical engineering professor at the University of Minnesota and study co-author, "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."
The research considered battery-electric vehicle efficiency only in California, given the level of EV adoption in the U.S. at that time. Based on the California modeling, "We find that driving slower is beneficial for EVs as well," Northrop said.
The study found differences among states, with Nevada seeing elevated speeding prevalence as well as high speed excess. There was high speeding prevalence in Florida, Georgia, and North Carolina, though those states did not necessarily exhibit high speed excess. Montana, Wyoming, Idaho, and South Dakota showed both low speeding prevalence and speed excess.
Original reporting: NBC Connecticut (Hartford) — read the source article.
