American motorists, already stung by an 80% increase in gasoline prices in the past year, sense that $5 per gallon is ahead, and they may be (regrettably) right.

A CNN/Opinion Research Corp. poll found that 94% of respondents expect to pay $4 per gallon this year, and 78% expect to pay as much as $5, CNNMoney reported Tuesday.

The national average currently is $3.62 per gallon as tracked by the Lundberg Survey, Bloomberg News reported. Many higher-cost areas of the United States -- including New York, San Francisco, Los Angeles, and Boston -- are already experiencing prices over $4 per gallon.

Further, traders and analysts say seasonal, structural, and geopolitical factors are likely to push gasoline considerably higher in the weeks ahead -- with gasoline's upward arc lasting months, if the price of oil continues to rise.

Primary culprit: Rising oil prices

The biggest factor in gasoline's rise is the price of oil, which Tuesday topped $122 per barrel in NYMEX trading for the first time in its history. Oil is up more than 100% since 2006. In November 2001, oil traded at about $17 per barrel. Moreover, because the crude component accounts for more than 60% of the price of a gallon of gasoline, refiners have passed that added cost onto consumers.

Second, even though U.S. gasoline consumption has declined weekly for about three months, on a year-over-year basis, the U.S. refinery system, due to several factors, is barely adequate, independent energy trader Jim Dietz told BloggingStocks Tuesday. Dietz said a lack of capital spending over a more than a decade, current-year refinery maintenance, and a reluctance by refiners to refine gasoline amid lower margins, has pushed wholesale gasoline prices higher, even as Americans cut back gasoline consumption.

"The U.S. consumer is doing his/her part, but the cost of oil and the refinery factor has left Americans with nothing to show for it," Dietz said. Dietz added that he now expects gasoline prices "to at least increase another 30-40 cents this summer" to a national average above $4 per gallon.

First demand, now supply problems

Economist Glen Langan took an even more pessimistic view. Langan said most of the oil price rise during the past three years has been demand driven, primarily increased demand from surging economic growth in China, India and Latin America. However, recently supply issues in the world's current political hot spots have contributed to oil's rise to its record $122 level.

Problems in the oil producing states of Nigeria (civil unrest), Venezuela (reduced production), Mexico (oil field production drop), Iraq (Iraq War, insurgency), and Iran (nuclear power dispute) are weighing on traders' and oil purchasers' minds, pressuring them to bid-up oil's price, Langan said. A production decline anywhere in the world would drive prices higher, due to the historically small, 500,000- to 750,000-barrel per day surplus between global oil supply and demand, he said.

Further, if multiple oil producing states have problems, oil prices "will move quickly toward $150 per barrel, and higher, if the problems were not rectified," Langan added.

Economist David H. Wang doesn't want to think about the implications of $4 per gallon gasoline on the U.S. economy. Wang is in the camp that argues the U.S. economy cannot grow at adequate levels with sustained oil prices above $100 per barrel, due to the high price's evaporation of consumer disposable income and fanning of inflation, among other negative effects.

The U.S. economy, Wang said, "has already slowed to a crawl with gasoline at $3.60 per gallon and due to the housing slump." A national average over $4 per gallon, "would delay any U.S. recovery by at least six months, and that's a rosy scenario." The added costs to businesses, public institutions, and commercial transport "would force structural changes in the U.S. economy not seen since the last oil shock in 1979-80."

"But those structural changes take time and have enormous costs. It would be the worst economic situation for the United States in a generation," Wang added.