When Gov. Mark Dayton announced yesterday that he had created a task force to find new revenue sources for transportation funding, it revived fears that the state might turn to taxing motorists based on how many miles they drive. It’s a terrible idea, because tracking miles would also almost certainly mean that the government would always know where every motor vehicle is and had been, a massive intrusion on privacy.

On the face of it, taxing drivers on a per-mile basis makes sense: The more one drives, the more one should have to pay into state funds dedicated to road maintenance, bridge repair and the like. The trouble with the idea, which MnDOT has been studying, is that the only way to total up each driver’s mileage is to track where vehicles go; and no one can seriously believe that our governments, which routinely fail to protect other confidential personal data, would truly keep travel data private. It is not hard to imagine nefarious purposes to which such data could be put.

The bottom line is that where people go, and when, is certainly not the government’s business.

While it makes a great deal of sense to base transportation taxes on actual use, any system which attempts to do so needs to protect Minnesotans’ privacy and not subject their every movement to government scrutiny.