Using your link...

"The drivers volunteered for the test and will be paid $300 each."

Who doesn't want to get paid to see how much they drive? It would also be paying for their fuel and any mileage tax.

"The test includes an elaborate system for refunding the state fuel tax paid by the volunteers. If the system ever becomes common, Whitty said, the reimbursement would have to be simpler."

So it's not just anal rape, there's an upside.

"He said Oregon is the first state to EXPERIMENT with a mileage fee, although the Congress has authorized eight such projects over the next five years."

Just that, an experiment(s). Good luck convincing a bunch of angry rich white guys to agree on it (Congress).