Obeying speed limits could save millions at the pump
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, according to the study published Thursday in the journal Communications Sustainability. The analysis covered roads with speed limits of 45 mph (72 kph) and higher.
More than 43% of studied trips included at least one instance of speeding, and drivers spent nearly 12% of their driving time above the posted limit, the researchers reported.
While many drivers say that speeding saves them precious time, the study found that is not really the case. With an average daily driving distance of 28.6 miles (46.03 kilometers), driving at or below the posted limit would not add even a full minute to a driver’s commute, the researchers found. The 28.6-mile figure comes from the same study.
HiRoad, in a separate driving analysis, estimated that driving 45 mph in a 35 mph zone saves roughly six minutes on a typical trip, while driving 75 mph in a 65 mph zone saves about two minutes.
The study also found that abiding by speed limits could save U.S. drivers millions of dollars at the gas pump and eliminate millions of gallons of fuel each day. That fuel, when burned, emits planet-warming greenhouse gases into the atmosphere. The findings arrive as gas prices remain elevated through the summer months, adding to the cost of day-to-day driving and seasonal road trips.
The study’s authors said changing driving habits would produce measurable environmental and financial benefits while not adding a full minute to a driver’s commute.