The price of gasoline goes up another nickel a gallon tomorrow, but this time motorists won't be able to blame greedy oil companies, rapacious service station owners or Saddam Hussein.

It's the government's fault.

The 5-cent rise in the federal gasoline tax is part of the package of tax increases and other "revenue enhancements" included in the federal budget approved by the Bush administration and Congress a month ago.

The federal tax on gasoline rises to 14 cents a gallon from 9 cents, and the tax on diesel fuel goes up to 20 cents a gallon from 15 cents. The Treasury expects the tax will bring in about $5 billion a year.

The tax increase likely will help propel gasoline prices to their highest levels ever in the United States. Nationally, the current average cash price of a gallon of self-serve unleaded regular is $1.366; the Washington area average is $1.398, according to the American Automobile Association.

Both have fallen slightly off their respective peaks in the past couple of weeks as crude oil prices have softened somewhat, but gasoline prices still average 25 or 30 cents higher than they were in July, before Iraq invaded Kuwait and upset world oil markets.

Although the higher gas tax will increase federal revenue, analysts don't expect it to help in the cause of energy conservation. There's almost no indication that Americans have greatly curtailed their driving since prices began to climb -- AAA says driving during the Thanksgiving holiday was actually up 3 percent from last year -- and experts say the extra nickel-a-gallon is not likely to dampen enthusiasm for the road.