A gas tax has been tossed around quite frequently as a method to both pay for transportation needs and encourage the use of other forms of transportation (e.g. walking, biking …)
Yes, the idea is that the gubb’mint would spend the extra tax money on The Best Alternatives(tm). The theory here is that thousands of years of tradition of government blowing the vast majority of its tax revenues would suddenly be cast off and you could sleep easy knowing that clueless politicians are disbursing your hard-earned dollars better than nobel prize winning energy physicists (or so the government says and wants you to assume).
What he said.
I don’t think a gas tax is necessarily a bad idea. Trusting the government to implement said tax and use it as directed is the problem. Maybe all we have to do is wait for the politicians to not run for reelection, and then they’ll “do the right thing.”