crow's Journal: Gas Tax at 40%

Today's thoughts on taxation:

The state tax on gas is $.21/gallon in Massachusetts. The federal tax is $.184/gallon. That's $.394/gallon, putting the pre-tax price at the pump under a dollar a gallon at the cheaper stations.

That's currently about a 40% tax.

Are any other forms of energy taxed at anything close to 40%?

Now granted, the government spends a lot of money keeping the transportation system going, but is 40% appropriate? How much does Massachusetts spend on transportation (excluding the Big Dig), compared with how much it brings in from the gas tax? What about the federal government?

Are gas taxes subsidising other government programs, or are other taxes subsidizing transportation? There are good arguements to be made for which way (if either) it should be, but I just don't have the information.