[Alberta's Child]

I don't think a GPS-based system would be the best way to do this. All the research I've done indicates that an electronic interface between a vehicle and a reader at an inspection station would be more practical. Of course, this was originally proposed as a revenue measure for state governments, so I'm not sure what the CBO has in mind.

The irony of all this is that this kind of measure is being proposed to address declining fuel tax revenues due to several factors, including: (1) more fuel-efficient vehicles (under Federal fuel efficiency mandates), and (2) more and more cars on the road that don't use gasoline (again, under Federal mandates).

[DoctorBulldog]

The GPS technology is already “shovel-ready” and proven.

Rather than start from the ground up to design, test, and implement a whole new “smart” metering system-—which would take about a decade at the pace the government works (remember how long it took to get your watered-down HDTV?), it is more feasible to install a ready-made GPS unit and program it to dump its memory when given the correct set of commands. I do it all the time with my GPS device. I know everywhere I’ve driven in the last three years and how many miles. It’s all right here on my computer.

Cheers