Gov. Deval Patrick has proposed hiking the gas tax, but he’s also looking at ways to wean the Commonwealth off it. Ergo, a few sentences in his new transportation plan authorizing the Registry of Motor Vehicles to study the possibility of a Vehicle Miles Traveled (VMT) fee, through which motorists pay based on the number of miles they drive in-state, rather than the amount of fuel they buy. The goal of VMT is to create a stable revenue stream for road maintenance that won’t decline as cars get increasingly fuel-efficient. Reacting to concerns about cost, and fears that the state government want to track just how often we all hit the Dunkin’ Donuts drive-thru, Transportation Secretary James Aloisi has emphasized in his blog that all Patrick’s bill does is give the RMV permission to explore the idea; it doesn’t lay out any specifics.

Judging from James Whitty’s experiences in Oregon, where VMT has been in play for eight years, Patrick and Aloisi may want to get more specific about what is and isn’t on the table, even at this preliminary stage. Whitty is the Oregon Department of Transportation official who oversaw a 2001 task force that studied the VMT, and the pilot program the group created. From 2006 to 2007, 260 Portland-area drivers volunteered to have mileage-readers installed in their cars; several local gas stations installed corresponding technology to measure the miles. When drivers filled up their tanks, they paid a flat rate-per-mile fee instead of the state gas tax. The pilot technology stopped counting miles whenever a driver crossed into another state, though Whitty stressed that the readers didn’t record or track a car’s geographic whereabouts.

Whitty says his first-in-the-nation pilot program showed that VMT technology works, but he also cautions that it is not yet hacker-proof or ready for a statewide rollout. He also says the challenge of switching from a statewide gas tax to a VMT in Oregon is more political than technological — and thinks that open-ended language early in Oregon’s process actually increased, rather than decreased, voter anxiety. He suggests that if Massachusetts wants to avoid some of public outcry he’s experienced in Oregon, legislators should write privacy protections into any law that authorizes a study.

I spoke with Whitty by phone about Oregon’s now-completed pilot program, and his advice for states considering a VMT.

When and how did the idea of a VMT charge get on Oregon’s radar screen?
People have talked about a VMT charge for several decades. In 1996, our governor proposed charging by the mile, but they couldn’t figure out a system to do it except for self-reporting. But that creates a big bureaucracy to make sure people aren’t cheating and to enter the data. So nobody’s ever done it. Starting around the late ’90s, technology started to become available. So, our task force sorted through 28 different options for funding, and settled on a per-mileage charge, because it could be done on a broad basis. The reason the gas tax has worked for us for 90 years, until now, is the idea is: If everyone pays a little, you get a large amount of revenue to take care of this huge infrastructure. But now there’s a big spread between what some people are paying who drive average motor vehicles and what those pay who are on the cutting edge of fuel-efficiency. We expect that more and more people will move to fuel-efficient cars, or even electric cars (which won’t pay any gas tax.) This is happening in every state and at the federal level. A gas tax isn’t going to work long-term.

Who besides Oregon is working on this?
Germany has put together a weight-and-distance tax for commercial vehicles. There is no place in the world that’s doing a distance-based charge for passenger vehicles. Oregon has done the first pilot project, we believe, in the world. It’s a very small one, and it was designed to prove the concept, not to prove that we’re ready to go because we’re not. The Netherlands is putting together a system that they hope to run a broad-scale test on in 2012, and do full implementation in 2014.

You just completed a pilot-program that shows the technology works, although you’ve also said it isn’t perfect. What needs to happen for Oregon to have a statewide VMT?
First, there has to be a state law passed. Second, we choose a particular system to develop the data and collect the charge, and then determine what the best technology is for that system. There’s security that needs to happen, to make sure no one can hack into them. And we have to work with the auto-makers, and the fuel distribution industries, too. The final thing is to prepare a rate structure that we can recommend to the Legislature. This is largely misunderstood; [in Oregon] people assumed a rate structure and got mad. But there is no rate structure. We tested a flat one, but it doesn’t have to be. There’s a lot of flexibility. There could be different rates for different vehicles, or for different geography.

One of the concerns of environmentalists in Massachusetts is that the minute you get rid of a gas tax, you lessen the incentive to drive a low-emissions vehicle. When you talk about flexibility, do you mean a VMT could be structured to reward for high-efficiency?
Yes. If I had to guess, I’d say the upper-end — say, 40 miles a gallon and above — would be a flat rate. You want everyone driving that kind of vehicle, and they’ll all pay a basic charge. Then below that, there might be a multiplier. So a car that gets 30 miles a gallon might pay twice the flat charge. A Hummer might pay six times the base rate. So you can encourage vehicles to trade up [to greater efficiency], but there’s no real hit to the funding stream if vehicles go up to 100 miles a gallon in efficiency. There are other things you can do with identifying people who are low-income, or commercial working vehicles. All this can be accomplished through the technology.

Is there the political will for this to happen statewide in Oregon?
People who work in transportation policy are embracing this. But there are those who are concerned because the reaction of the public has been largely negative. I’m not going to hide that. I’ve been dealing with the public on this for seven years and am starting to understand it. They’re reacting not to what we did or intend to do, but to something else. There are people who presume that the government will track them, but we eliminated the ability to track. It’s not a navigation unit or GPS. There’s no satellite that someone can pick up. The device can track miles, but nobody can track the device. There’s no map; there are just coordinates, so the device knows whether it’s in the state or not. There’s no ability to create a travel history. All it does is count miles. People also assume a rate structure, even though one hasn’t been proposed. They also assume things like a huge government bureaucracy, even though we designed it to use the gas tax bureaucracy.

What do states considering a VMT need to think about, perhaps especially as far as winning public approval?
I think the Legislature ought to establish some policies for development. We had four legislators on the task force and they helped guide our research, but I didn’t have the foresight to go back to the Legislature and have [guidelines for a VMT] established into law. A legislature could say at the outset: The system must be commercially viable; it has to protect the privacy of the public; there needs to be a low operating cost relative to revenue; it needs to have the ability to assess variable rates depending on geography and fuel-efficiency; and it needs to allow for a gas tax credit if you’re going to replace the gas tax.

So Oregon didn’t do that?
No, it wasn’t put into law. We followed those principles, but not because we were required to. So we couldn’t point to that for the public. Even so, everyone should expect there still to be a negative reaction, for reasons I’ve come to understand. Until a motorist understands what the impact to them is going to be, they will oppose it. Uncertainty, especially during times like this, causes them not to want to go into the unknown. So the Legislature has to work to remove the fear of the unknown, by creating some knowns.