If the cost of transportation is decreased - the market will increase transportation. IE more miles - more travel.
No issue here - move along folks - nothing to see here!
More taxes.
People will not save a dime at the pump even though they fill their tanks once a month versus four times a month as they do now.
Monthly budgets for individuals to purchase gas will be unchanged.
Those that own hybrids now do indeed realize a savings at the pump. But that window of savings opportunity will close as States ratchet up their gas tax in response to hybridization of autos.
In fact Washington State is proposing a special tax on hybrid owners.