The federal gas tax as a major source of revenue for transportation is going down as driving decreases -- VMT in the US as elsewhere in the developed world is on the decline -- and gas tax revenues are likely to go down further as fuel efficiency standards go up. Is the VMT tax a better way to go? San Francisco is studying the option, and it's mentioned as an option in Southern California's Regional Transportation Plan. Surveys show that people hate the concept of the government monitoring odometers but, interestingly, people who are part of  VMT fee studies seem to feel very positive about the idea after they've participated in the trials (40 percent of participants in an Iowa study viewed it negatively before the trial and 70 percent viewed it positively afterward). Is the VMT tax an idea whose time has come?
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