Gas taxes in the U.S. are among the lowest in the developed world. The supposition that raising the gas tax would reduce quality of life seems in doubt. Many countries with a very high standard of living also have a very high gas tax. I say triple the gas tax.
"Germans pay an average of $3.25 in taxes on a gallon of petrol, among the highest for the OECD’s mostly rich members. Citizens of other European countries such as Finland, France and Norway (not shown) also fork out more than $3 per gallon in tax. But America’s gasoline taxes average a mere $0.39. America’s reluctance to tax petrol heavily helps to explain why Americans drive much more than Europeans (though the country’s size is a factor too), and why they love gas-guzzlers. Mexico is the only OECD country that subsidises petrol." Source: http://www.economist.com/node/17101124