It may be time to rethink your summer vacation plan.

With gas prices forecast-ed to reach $3 a gallon, you may be paying almost 40% more to drive to Disneyland.

An early warning sign is $70-a-barrel oil.

U.S. retail gasoline prices are the most expensive in three years, reports the Energy Information Administration. The national average is about $2.86 a gallon.

In California, Hawaii and Washington, prices have already reached $3.

Tax cuts and economic growth has boosted demand. If that continues, you may be able to afford to pay more to fill up your tank.

When prices fell in 2014, many of us took advantage, driving more than ever and buying larger, less fuel-efficient cars. In 2016, prices fell well below $2 a gallon, far from when they reached $4.11 in 2008.

Some economists say the U.S. is less likely to be the victim of foreign price manipulation since it produces record levels of 10.7 million barrels a day.

Rising prices can fuel inflation, lift interest rates and lower consumer confidence.

Morgan Stanley estimates that if gas averages $2.96, it would take $38 billion from spending on other goods and wipe out about 33% of additional take-home pay from federal tax cuts.

Airlines and shippers will pay more for jet fuel and diesel, a cost they will pass along to the rest of us.

Industry experts say they aren’t concerned.

“Three dollars is like a small fence,” Patrick De-Haan, a petroleum analyst at GasBuddy.com told The Wall Street Journal.

“You can get through it, you can get over it. But $4 is like the electric fence in Jurassic Park. There’s no getting over that.”