One of the perennial concerns about paying for roads through a vehicle-mile fee rather than a gas tax is protecting privacy. While this can be done using a GPS system, such systems would require a lot of new infrastructure to collect the data.
Researchers at the University of Minnesota have proposed an alternate system that relies on existing cell phone infrastructure and the electronics that have been built into virtually all cars at least since 1996. A device would be added to each car that tallies miles driven and text-messages mileage data when it is within range of the cell phone network.
