Portland, Oregon, has installed global-positioning monitoring devices in 300 vehicles as part of a study that could lead to a tax on the miles people drive rather than the gallons of gas they dispense at the pump. The idea, which has fans in several states, including Colorado, could help states pay for deteriorating roads at a time when existing gas taxes are failing to do so, according to The Associated Press.

And, as U.S. Representative Peter DeFazio of Oregon notes, gas taxes just aren’t going to keep up as people turn to more fuel-efficient cars.

But critics worry that the GPS systems required to make the plan work allow the government undue intrusion into privacy. Not only will the government know where you are, it will also know how fast you’re going and can even send you a speeding ticket without ever pulling you over, opines conservative blogger Richard Miller at MileHive.

Although gas prices are down, don’t expect that to last forever, writes the Colorado Springs Gazette, quoting one expert who predicts gas in the $5-a-gallon range in the next two to three years.