Is it appropriate to charge users an additional fee for something that is already being paid for as a whole by the community at large? That depends on what you're paying for. I don't agree with the proposal in the article for reasons expressed later.
However, some states have some major highways that are toll roads. The tolls were put in place to pay for the building of and maintenance of that roadway. The roadway usually being a VERY convenient stretch to travel. Take for example the New Jersey Parkway. Prior to the Parkway (before my time so the "antiques" around here from that area might correct me

), you only had highways. Highways, that as the population grew began to have more and more traffic lights. If one was to try to take free highways in New Jersey from the north to the south it would likely take 100 times as long, and easily 5 times the gas. People pay the tolls because they want the convenience. Furthermore those toll vary depending on what you are driving, so that those vehicles that do the most damage to the roads (Semi-Trailers and the like) pay more.
The per mile proposal is interesting, but it is a regressive tax if there ever was one. A person earning 100,000.00 a year would pay the same per mile as someone earning $30,000.00 a year. Plus, as you point out, most if not all of the products and services we enjoy use the roads to bring them to us so almost all of the things we pay for, from food to telephone service would go up in price to pay for the new tax. Since consumable goods make up a much greater percentage of the average budget of someone who is poor than someone who is wealthy this tax would have a much deeper effect on the wallet of the working poor then the well-to-do.
People complain about the income tax burden being heavier on the poor them the wealthy. People's opinions differ on the validity of that argument but this tax surely would be a much heavier burden on the poor then the wealthy. Just as Gas Taxes and Property Taxes are now.
Would you support the Oregon version that replaces the gas tax with the road fee, would you support some other variation of elimination of a current system in favor of this new system? No. It takes away all of the incentives for someone to have a more fuel efficient vehicle that the gas tax helped create and replaces it with a tax that is equally regressive on the poor (In the case of fuel efficient vehicles, the gas tax is less on individual with a fuel efficient vehicle then one with a gas guzzling SUV or older vehicle. With the milage tax, they both pay the same).
Would you support it in a conditional form, specifying that the revenue must be spent fully on, and dedicated only to, maintaining roads? That is what the Gas taxes were supposed to be in most areas. In my former home state of New Jersey the people were promised that the revenues for casino gambling would only go to programs for the elderly and schools. Then when the lottery was being voted on, they were promised that the casino revenues would only go to programs for the elderly and the lottery revenue would only go to the schools. Further, they were promised that the tolls on roads would only go to the construction cost and maintenance costs of those roads. Before the ink was even dry on each of those pieces of legislation, the state government drafted new legislation to re-direct these revenues to the general fund as well as all sorts of pet projects.
Provisions like this are only as good as the next piece of legislation to change them. In other words, they mean nothing.
Is this just another form of double taxation? In a sense, but which would you prefer? an income tax and a gas tax, or just an income tax that has to be increased to cover the costs of the operation and maintenance of the roads? Different taxes allow people to better control their budgets to a degree. This particular tax, actually increases the cost of living for everyone who has to commute to a job, a supermarket, a school or a church. It does so in a way that is much more significant and damaging to the budgets of the "have-nots" then the "haves".
Is there any merit to the "Big Brother" suppositions at the end of the article?Could be. In New Jersey, the state promoted something called "Easy-Pass". It was a electronic device, you put in your car to have your tolls on toll roads recorded and then you would be billed at the end of the month. It was promoted as a way to speedup tolls, simplify expense reporting, and reduce operational cost of the roads (by reducing the number of toll-takers needed).
What people didn't expect was the speeding tickets they got in the mail. When you pass a toll the time and date is recorded. If you pass the next toll to soon, as to show that you had to be speeding, the speed you must have been traveling at is calculated and you get a ticket! Seems like big brother to me.