If the red light cameras don't find you, the GPS tracker will
There are some in the government that would love to replace the gas tax with a per-mile tax. They would use GPS to accomplish this, by tracking every move you make and every mile you drive. If the environment were truly a concern of these people, they would realize that a gas tax more heavily penalizes those who use more fuel and encourages conservation. Of course, the environmental rhetoric really has little to do with the environment and has everything to do with controlling the lives of the subjects.