Pinning Down Road Trip Gas Costs

Despite the high gas prices, some 31 million Americans are expected to hit the road this Memorial Day weekend, up slightly from last year, according to AAA.

And if you're worried about how much your trip is going to cost you in gas, there are ways to crunch the numbers before you head out.

As The Early Show consumer correspondent Susan Koeppen explained Tuesday, two Web sites, fuelcostcalculator.com and roadtripamerica.com enable you to calculate what gas will run you for your trip, after you answer a series of questions ranging from the make and model of your vehicle to your starting and destination cities.

Koeppen demonstrated both sites.

Fuelcostcalculator.com is run by AAA, which says traffic on the site doubled last month. It says consumers are comparing different types of vehicles, which could mean they're deciding whether to take the SUV or the sedan, or rent a smaller car.

Roadtripamerica.com says its traffic has shot up 40 percent, and many drivers are planning coast-to-coast trips this year, feeling that, with gas prices going up, they'd better take the trip now, in case future, higher prices prevent them from taking it altogether.

Koeppen says, in many cases, the cost of gas could go a long way toward determining whether it pays to drive at all, as opposed to flying.