This is a completely unacceptable idea.

would not this end up being public information. Gee maybe we could download the info on some of our elected representatives. First time that happened I bet the whole system would get canceled.

What is a fair contribution from various classes of road users towards paying for roads?
All of us benefit from roads whether we drive cars on them or not. For all of us, the necessities of daily life come by road. And all of us can and do pay an indirect tax on the truck traffic that delivers those necessities.
It is useful to divide road use into cars and trucks. That is because there are two types of road/bridge damage that must repaired/replaced. Weathering happens to roads independent of traffic. Wear and tear damage happens every time a vehicle goes over a section of road - more heavily used roads wear out faster. But the damage becomes disproportionately greater with axle weight. It is a third or fourth power relationship. A truck with a 5 ton axle does the same damage in one mile as a car with a 1 ton axle does is 125 miles!
A "fair" tax would have road repair funds coming from general funds and from use taxes largely paid by truck traffic. It might very well result in an increase in direct and indirect taxes paid by city dwellers, at least some of whom are quite smug about not owning cars. Those folks would however approve of the possible resurrection of some of our zombie rail lines. And they would approve of the relatively increased taxes on SUVs - a 1 1/2 ton axle Suburban would pay a 3 1/2 times the mileage rate of a 1 ton axle sedan for that portion of the tax on actual road use.
Why jump into some sort of big brother monitoring system based on GPS - which can (and will) probably be hacked out of general principal and a desire to dodge tax?
News flash - we have these things called odometers. They are reasonably tamper proof and can be read on, say, a quarterly basis. Or you can upgrade them to EZ-Pass style RFID. If this type of tax is the way to go, then the problem is solved without Big Brother watching full time with an expensive and intrusive GPS system.

We already pay per mile..it's built into the gas tax. Vehicles with lower mpg will already be paying more for the same # of miles driven.

There is no guarantee that these funds would be used for roads and no just dumped into a general revenue pool for some other purpose...

Frankly, it is nobody's business where, how far & when I travel...

tcc3 - while the current system is the simplest and easiest to administer, this GPS monitoring proposal isn't going away. The political classes' urge to micromanage and acquire more power remains their only core principle.
If I were highway funding czar? I'd look for a system that has gas taxes as we have now as one component. This won't pick up the use by cars powered by electricity or pixie dust. It also doesn't properly account for relative road damage. So, let's add an annual tax that's based on number of axles times axle weight times miles traveled. It doesn't matter what the power source is or what the dimensions of the vehicle are, just the weight. And I'd immediately revoke the lower CAFE standards for light trucks/vans/minivans. Let's have a level playing field. The gas tax is somewhat like an access fee, the weight damage tax is like a use fee.

chuckr,

1st of all, I would argue that the gps system violates the right to privacy which has been used to justify/protect a lot of things over the years. Does anyone know where the ACLU stands on this one?

Not having done any analysis, but if funds from the gas tax were directed solely towards road repair/maintenance and not other efforts (i.e. public transportation...let it be self funding) what is the real shortfall in revenue?

IMHO, the government, on every level, does not have a revenue problem, but a spending one. If we identify transportation infrastructure as a key priority, then necessary funds from the existing revenue pool should be dedicated to it over less important expenses. In other words, cut spending on something else...

You may argue that considering our current political climate that my position is not realistic and you very well may be right. However, when looking @ any problem with the government, I think that we need to approach solutions from the standpoint of increasing (or at least maintaining) the level of freedom that the citizens of the USA have. The more (economic) freedom that people have, the more revenue the government will collect anyway from increase commerce.

Given your position that the gps system (or some odometer reading) is a inevitable, then I would argue for the elimination of the separate gas tax. Otherwise we are looking at another double taxation situation. Furthermore, any increase in transportation costs is eventually going to lead to higher end consumer prices on good and services. This will have the typical reverse outcome from the government's intentions. As the increases will be regressive in nature, calls will be made for more government services/help/funding/whatever which will only lead to higher taxes and regulations and so on and so far....

Enough already.

tcc3 - you misinterpreted my comments. GPS monitoring is not inevitable. However, the drive to implement a GPS standard is inevitable. A further point is that you need a reasonable counter proposal that a) isn't needlessly complex b) fairly apportions costs c) can be easily implemented and isn't vulnerable to spoofing. The GPS system is a politician's dream. It will offer the opportunity, in stages, to increasingly monitor people's ordinary comings and goings that don't need monitoring. It will need a built infrastructure, a Federal oversight agency division and fifty state oversight divisions. Pork and patronage and another unwarranted increase in surveillance - politicos will love it.
You may argue - and I will agree with you - that we have a spending problem, not a revenue problem. But for decades, we have accepted that roads are funded by user fees called gas taxes. I think the battle you can win is for a user fee that doesn't involve Big Brother monitoring. I like the idea of vehicle classes that pay based on the wear and tear they inflict on the roads and bridges. Trucks would pay a lot more and the indirect users - city dwellers - who now get a free ride on cost of delivering their goods and services would see that reflected in their costs. As many of them are probably liberal and anti-car, permit me a little schadenfreude.