Thousands of cars and trucks speed through the Maine Turnpike tollbooths every year without paying. Over a six-year period, they have collectively run up a bill in excess of $800,000.

That’s a lot of money, and the state rightly has gone after those scofflaws, impounding vehicles or – in the case of one Rhode Island company – impounding a fleet of trucks. It would be a mistake to give drivers the idea that they could get away with not paying a toll. But it would be a bigger mistake to exaggerate the size of the problem.

The Maine Turnpike’s experiment with electronic tolling, which allows E-ZPass customers to pay their toll without stopping at a tollbooth, has been a huge success.

The unpaid tolls amount to less than one-half of 1 percent of the money the turnpike takes in from its tollbooths. The thousands of vehicles that drive through the tollbooths and never pay a bill have to be counted against the millions of vehicles that use the turnpike every year.

In other words, electronic tolling works. That’s an important point to consider as the state looks at how it should fund its highway infrastructure.

The gas tax, Maine’s traditional source of highway funding, does not produce enough revenue to support the system that we have. Gas tax revenues fall short of needs every year, and the state has filled the gap with borrowing. Voters have approved $100 million transportation bonds in four of the last five years, but no one thinks that it’s a sustainable way to keep up with wear and tear on the roads.

Tolling, like the system on the Maine Turnpike, is fair to all users and non-users. Heavy vehicles can be charged more, reflecting their impact on the roadway. Owners of vehicles with electric motors, who pay little or no gas tax, don’t escape paying their share of the system’s costs. Routine road maintenance can be paid for on a pay-as-you-go basis, leaving long-term debt for one-time projects.

The Maine Turnpike’s experience shows that toll revenue is steady and predictable, and you don’t have to create traffic problems with long lines at tollbooths. Electronic tolling is not a futuristic pipe dream, but a technology that is available to us right now. And we know it works.

That may sound like an odd point to make when the Turnpike is holding more than $800,000 in unpaid debt. But even there, the Turnpike is making progress.

Most of the nonpayers are out-of-state drivers, and Maine is negotiating agreements with their home states that will allow more efficient collection actions against them. Maine has a three-way agreement with Massachusetts and New Hampshire under which scofflaws won’t be able to re-register their vehicles in their home state without paying any tolls they owe elsewhere. As similar agreements expand to other states and Canadian provinces, electronic tolling will become even more reliable and common.

Gov. Mills created a blue ribbon commission to look at creating a sustainable path forward for highway funding. We think the Maine Turnpike offers a good example of how such a system could work.