Increasing the gas tax will be cyclical. We're seeing it now as the call for alternative fuels and more fuel efficient cars are paying less in gas taxes. That is the crux of the issue.
Increase the tax on gas, cars become more economical, less gas being purchased, less taxes coming in to pay for repairs, tax has to increase again, cars become more economical, less gas being purchased, less taxes coming in to pay for repairs, tax has to increase again, cars become more economical, less gas being purchased, less taxes coming in to pay for repairs, tax has to increase again, cars become more economical, less gas being purchased, less taxes coming in to pay for repairs, tax has to increase again.
--kC