If it's not bad enough that Maryland drivers will be suffering from the first of what now promises to be annual hikes in the state's gasoline tax, due to a combination of adding gasoline to the palette of items subject to the state's sales tax and eventual indexing of the existing gasoline tax to inflation, a pending federal bill may allow the addition of natural gas-based ethanol as an allowed blending agent, joining the corn-based ethanol that's currently allowed to comprise up to 10% of most available gasoline.