Which is cheaper, flying or driving? Crunch the numbers

If recent sky-high gasoline prices sent your spirits spiraling downward, take heart. By the time you read this, prices, goosed by a broken Arizona pipeline and refinery shutdowns after the East Coast blackout, may have fallen back to Earth.

Gasoline set records for weekly price increases in August, says the Energy Information Administration, or EIA, of the U.S. Department of Energy. California was hit particularly hard: Gas increased 16.4 cents a gallon for the week ending Aug. 25, versus 12 cents nationally.

Gas prices typically fall after Labor Day, and the restoration of supplies should help bring them down further. How fast and how far they will drop is “too difficult to know right now,” according to the EIA.

The high price of gas and the low price of airfares have revived -- at least among some leisure travelers -- the question of whether it makes more sense to drive or to fly. I analyzed this question using a trip for two from Los Angeles to Las Vegas as my hypothetical case.

Here are the statistics I began with: Regular, unleaded gas cost $2.13 a gallon in Los Angeles as of Sept. 2, the Travel section’s deadline, according to AAA. It is about 540 miles round trip from L.A. to Vegas. (Many folks know this, apparently; in June, 1.2 million vehicles passed the California-Nevada state line at Primm on Interstate 15.) If a vehicle gets 20 miles per gallon, gas at the current rate would cost about $60.

Round-trip airfares from LAX to Vegas are as low as $71, or $142 for two.

The cost of gasoline or an airplane ticket doesn’t provide a complete picture of costs, of course. There are indirect costs to consider, such as vehicle wear and tear, parking, travel time, convenience, safety and environmental impacts.

When gasoline was $1.40 per gallon nationally last year, Runzheimer International, a travel costs consulting firm, estimated that it cost 52 cents per mile to operate the “typical” car, an amalgam of several types of common cars. If you use that figure, the cost of a road trip to Vegas increases to almost $300. That’s a lot of quarters that could have been used in the slots. And it doesn’t include lunch in Barstow.

This round goes to flying.

On the other hand, if you own a car, you automatically have such costs as car payments and insurance, even if you never drive to Vegas. Plus those $71 airfares are not always available at the times you need to fly. At peak times (weekends, for most of us), you’ll pay $130 per person or more for a flight, plus air- port parking or the cost of a shuttle and a cab in Vegas to your hotel.

Driving gets this point.

In the final analysis, the actual out-of-pocket costs for the two modes of transportation appear to be a wash.

But the analysis doesn’t really end there. For a short trip, time is an important consideration. Las Vegas from Los Angeles by car can be a four-hour zip through the desert or a tedious seven- or eight-hour trudge through weekend traffic. For discussion, we’ll say it’s around five hours.

Flying takes about 50 minutes. But you have to factor in an hour or so driving time to the airport and time to park the car. You’ll need to get to the gate an hour before your flight. Then there’s the time to get off the plane, grab your bags and catch a cab in Vegas. Even if your flight arrives on time -- and 14.5% of the time it won’t, according to Department of Transportation statistics on on-time performance for Vegas flights -- your quick flight is three hours plus.

Still, flying has a slight edge over driving, so score one for flying.

And don’t forget safety. Flying has long been one of the safest forms of transportation. U.S. automobile travel averages .88 fatalities per 100 million passenger miles; airlines average .02, according to the Air Transport Assn. Statistically, you are 44 times more likely to arrive alive at your destination if you fly.

A big plus for flying.

The environmental costs of travel are tougher to measure. A 2001 study by the Federal Highway Administration put the cost to society of driving a car -- that is, the crashes, pollution, noise and congestion -- at $446 billion in 2000, or about 18 cents per mile driven. Taxes, fees and insurance companies picked up only part of the tab, leaving $257 billion to be absorbed by other drivers, nondrivers and society at large, according to a 2001 study by Redefining Progress, a social and environmental issues think tank in Oakland. That’s something to talk about as you two eat a burger at Bun Boy in Baker.

Air travel, of course, has its environmental cost. Check out the air travel calculator at www.climatecare.org to figure out the amount of emissions you are generating on your flight. The L.A.-Vegas price comes out to 85 cents per person -- less than a tip for valet parking. Score one for flying.

Convenience is one area in which driving clearly trumps flying. You can pile everything in the back of the car, taking all the nail clippers and golf clubs your trunk will hold, and leave on your own schedule. If you want, you can smoke the entire five hours, take a rest stop when it suits you and have your choice of food (more or less) along the way.

Of course, if you fly, you won’t have to sit behind the wheel of the car for hours as the traffic crawls along Interstate 15. And a flight attendant will serve you a cocktail when you’re airborne. No attendant and definitely no cocktail on the road trip.

Quantifying travel decisions is difficult. But considering cost, time, safety and environmental impact, flying appears to be the clear winner.

Yet there is something romantic about being behind the wheel on the open road, man (or woman) and machine as one as they barrel through the desert night. If only it were quicker, safer and friendlier to the environment but, then, I suppose one could say many of the same things about Las Vegas.

Jane Engle is on assignment. You can reach James Gilden through his Web site, www.theinternettraveler.com. Travel Insider welcomes comments and suggestions but cannot respond individually to letters and calls. Write Travel Insider, Los Angeles Times, 202 W. 1st St., Los Angeles, CA 90012, or e-mail travel@latimes.com.