By the Gallon or By the Mile? States Look for New Highway Revenue

California's high-gas-mileage cars and growing number of alternative-fueled vehicles are speeding the deterioration of the state's highways. It's not that they're uniquely hard on the pavement. It's because the drivers of fuel-efficient vehicles pay an increasingly smaller proportion of the state gas tax that accounts for about 30 percent of the state and local spending on highways.

As sales of fuels level off, so does the state's gas tax revenue. The disparity will only grow worse as vehicle technology improves and if more Californians can be persuaded to give up their car for public transit. Transportation planners estimate that California will fall nearly $300 billion behind in unfunded highway improvements over the next ten years, mostly in the form of deteriorated residential streets and arterial roads.

Simply raising the gas tax wouldn't be enough to fill the gap and would transfer more of the tax burden to drivers with conventional cars. (Some states are considering an annual highway user fee for the drivers of all-electric cars.)

As a funding mechanism, the gas tax is broken, and a consensus is forming around an alternative. The idea is to charge drivers for every mile their vehicle travels. Some advocates see highway user fees as a market-based way to manage a public good. Others see it as another way to get drivers out of their car and into public transit.

V(hicle) M(iles) T(raveled) pricing schemes -- alone or in combination with a congestion surcharge -- are already being explored in Oregon and Vermont and in Sacramento, Atlanta, and San Francisco.

Oregon has gone the farthest in experimenting with VMT as a substitute for the state gas tax. In a pilot program begun in November, volunteers are testing which of several methods of tracking miles traveled is least off-putting: from an annual odometer check to real-time GPS monitoring. One or more of them may become Oregon law by 2015.

VMT as a replacement for the gas tax has a sort of American sheen on it. Pay only for what you use! (Although we tend not to think of the things -- the sidewalks on the other side of town, the trees in someone else's park -- for which we paid but never use.)

Although mostly successful in its trial runs, VMT pricing faces many obstacles in California. Privacy advocates worry about the use of monitoring data. Tax dissenters worry how legislators will use new revenue. Policy theorists question if user fees price low-income drivers out of a highway system their taxes helped build.

And I wonder if outrage over traffic congestion is more class-based than we're prepared to realize, if all schemes to get drivers off the road are more about getting disquieting, anxiety provoking uncertainties out of our troubled lives. And how far will enthusiasm for user fees go to segregate our commonwealth into zones where wealth alone determines access and mobility?