Opinion: With highway funding in decline, mileage-based fees offer a solution

For almost a century, the HTF has relied heavily on gasoline and diesel fuel taxes, often collectively called the “gas tax,” for revenue. But the gas tax faces a fundamental challenge: In 2017, the average light-duty vehicle traveled 25.2 miles per gallon of gas, 22 percent higher than a decade earlier and nearly double the average in 1975. As a result, motor fuel consumption in the U.S. has flatlined over the last decade, despite millions of vehicles being added to America’s roads. The growing popularity of electric cars has also contributed to declining HTF receipts.

Since 2008, to make up for chronic funding deficits, lawmakers have moved $143 billion in general taxpayer dollars to the HTF. Unless Congress intervenes again, the HTF will be insolvent by 2021.