More than 1 million electric cars are now zipping (quietly) around the United States. That’s still a tiny fraction of the nation’s 260 million-strong vehicle fleet, but EVs hit a sales record of 208,000 registrations in 2018. As more mass-market plug-in models hit the showrooms, more charging stations pop up, and the menace of “range anxiety” fades, new EV drivers are born every day.
But are all those Bolts, Volts, Leafs, and Teslas paying their fair share for the asphalt they drive on? The Highway Trust Fund, the federal government’s purse for road maintenance, depends on the 18 cents per gallon U.S. motorists pay in gasoline taxes. But it’s nearly insolvent, in part because Americans drive more fuel-efficient machines than before. So states like California, Washington, and Illinois are mulling a “mileage tax,” where drivers pay a fee based on the number of miles driven, rather than the amount of gas they burn. Oregon, where a pilot program asks participants to pay 1.7 cents per mile in lieu of paying a gas tax, is the example to follow.
First: Just how much is the highway piggy bank losing because of the rise of EVs? Davis and Sallee estimate about $250 million a year, based on vehicle substitution trends and average miles driven. That’s a fairly modest hit, but per EV, it seems weightier: $318 annually, according to their estimates. This impact on tax revenues is concentrated in a small number of states where EVs are most popular and gas taxes are highest: In California, where 7.8 percent of all new car sales are hybrids or electric, the state is surrendering $90 million in annual revenue.
What’s more, Sallee and Davis estimate that two-thirds of those foregone resources comes from households that make more than $100,000 in annual income, since EVs tend to be more expensive to purchase than conventional cars and are disproportionately driven by more affluent people. This suggests that the under-taxation of zero-emissions cars has a “regressive” effect—it hurts poorer Americans more than rich folks.
So, should EV drivers cough up, and how much? Facing this question, the researchers consider some key economic tradeoffs. On the one hand, even though EVs help reduce carbon emissions and local air pollution, these virtuous vehicles still contribute to road congestion and collisions as much as anyone else. And we’ve seen that the federal coffers could use some support. Perhaps some tax is in order.