Collecting Road Taxes After Peak Gasoline

On Monday I was interviewed on Chicago's WGN Radio on the subject of switching the collection of federal highway taxes from the current assessment on motor fuel sales to a fee on vehicle miles traveled (VMT). The gas tax is always a hot-button subject, and when it's combined with potential concerns about privacy it becomes even more controversial. However, the path we're on is a slow-motion train wreck, for multiple reasons, and I'm relieved to see that with so much attention focused on other, larger aspects of the budget deficit and taxation, this relatively small yet important corner of the tax system hasn't been forgotten. It's high time to plan for how we will pay for the upkeep of our highways as sales of gasoline begin to decline.

The interview was prompted by some comments I made on this subject to Tom Curry of MSNBC. Since my conversation with him and then with Mr. McConnell of WGN I've been doing some more thinking about the problem, which I've discussed here since 2005. For some time it's been apparent that we have a disconnect between federal energy policies explicitly aimed at reducing our consumption of petroleum products and a road tax system that depends on the stability and growth of those sales. With gas prices again near their 2008 maximum and the auto industry required to sell consumers a more efficient mix of cars each year, it appears that US gasoline demand might have peaked in July 2007 and won't reach that level again. Lower gasoline sales mean lower gas tax collections, unless the tax rate is steadily increased, encroaching on one of the third-rail issues of US politics.

This is the long-term part of the gas tax problem. It's true that it takes decades to turn over the US passenger car fleet. Nevertheless, the more highly efficient cars are sold, including this year's crop of 40 mpg non-hybrids, plus hybrids, clean diesels, and a tiny but growing number of EVs and other cars using no liquid fuels at all, the harder it will become to fund the cost of road maintenance from its traditional source at the gas pump.

The problem has a more immediate dimension, too, because gas tax collections haven't been sufficient to balance the Federal Highway Trust Fund (HTF) for some time. According to a recent study by the Congressional Budget Office the taxes on gasoline and diesel fuel brought in about $32 billion last year, but between 2008 and 2010 an additional $30 billion had to be transferred from the general fund to the HTF to keep it in the black and avoid canceling or delaying projects. Given the deficit, such transfers add directly to the national debt. Nor is the current level of expenditures adequate to address the decay of many of our roads, as assessed by the American Society of Civil Engineers. This issue received a lot of attention in the aftermath of the 2007 collapse of the I-35W bridge in Minneapolis-St.Paul, but it faded after a few news cycles.

So we need to come up with more money to keep federally-funded highways in good repair, despite the principal funding mechanism being on a gradual but inexorable downward slope. States face a similar dilemma. Solving this problem requires creativity and most likely a new funding mechanism for all or part of a gap that is expected to grow in the years ahead. Simply extending the status quo will require steadily larger transfers from the general fund, exacerbating the deficit. It would also create growing inequities by weakening the long-established link between usage and financial responsibility, compounded by EVs and other vehicles that pay no road taxes at all under the current system. Unless you think EVs will never expand beyond a tiny niche of early adopters, that's unsustainable. (Some might argue that EVs should escape this tax as a further stimulus to sales, but in my view $7,500 per car ought to be inducement enough for anyone interested in buying one.)

There are several possible remedies for shrinking gas tax revenue, with partial or total conversion to a mileage-based system topping the list. It retains the fairness of "user pays" and encompasses all cars, whatever their energy source. It might also trade off a lower tax burden for the drivers of older, less-efficient cars for a slightly steeper bill for newer, more frugal cars. However, considering that the annual federal gas tax bill for someone driving an average car 12,000 miles per year is currently only about $100, any differences between the gas tax and a replacement VMT tax--not to be confused with a VAT tax--would be unlikely to influence car choice one way or the other.

If a VMT tax is the answer, the question of how to assess and collect it looms large. As I noted in the interview I worry about a tendency to rush to a technology solution, even though other options might do the job without requiring GPS-based tracking that a significant number of Americans would consider unacceptably intrusive. If you doubt that, consider the controversy over alleged smartphone tracking by Apple and Google. I would not dismiss low-tech methods such as odometer readings at vehicle inspections, or even self-reported odometer readings where such inspections aren't required. This might introduce new opportunities for fraud, but I'm willing to be that a GPS tracker could be spoofed, and all of these potential loopholes pale compared to the current problem of fuel tax evasion by organized crime and unscrupulous distributors and dealers.

I like the idea of testing this concept in a few locations, particularly if the tests include a wide variety of approaches. The slow uptake of EVs and the gradual shift of total fleet fuel economy give us enough time to find the best solution, if we start now. But lawmakers should ensure that such tests are finite and designed for quick evaluation, so that the window of opportunity presented by the broader tax reform discussions between now and the next presidential inauguration isn't missed.