In response to:
Taxes are not a good way for the government to try to influence people's behavior because the government becomes addicted to the money, and if higher prices do actually cause people to modify their behavior (like driving less) then the government complains that they can no longer balance their books, and they need even more taxes.
There are a few irrefutable laws of basic economics that are understood by practically everyone. When the price of a good rises, people will buy less of it. This is common knowledge to anyone who has bought anything ever. There is also the law of unintended consequences which states that actions, laws, and policies often have secondary effects that differ from the original actions intentions. We have seen this inevitably played out in most laws passed by Congress. Both of these ideas have been around for thousands of years and the father of economics, Adam Smith, articulated them himself...
With more and more Americans buying high-mileage gas-miser cars, Americans are able to drive more while using less gasoline--meaning that they pay less gasoline tax. (And those Americans who buy electric cars use almost no gasoline at all.)
You guessed it. Now the politicians are trying to figure out how to tax American motorists by the miles they drive, not by the gasoline they use.
GPS-based data recorders,that can be read by the same transponders E-Pass uses.
(that they already use at busy intersections,you can see the rectangular or square planar antennas on nearby poles,usually in pairs;makes me wonder if this wasn't planned long ago...)
that way,they get their money quicker.