Gas prices may not be at record highs anymore, but fuel still isn't cheap. The spikes in prices and the fact that global demand is likely going to increase has left a lot of drivers wondering if getting behind the wheel is even worth it. Does it make sense to drive to work every day, or can you save money and aggravation by taking public transportation? To find out, we looked at commutes in four American cities. 

In all cases, we assumed a commute in a 2008 Toyota Camry (which gets 21 mpg city, 31 mpg highway and 25 mpg combined) and a 15-mile one-way commute to work -- the average according to the Bureau of Transportation Statistics. We also assumed gas costs of $3.87 per gallon, which is the current national average as reported by AAA.   

Washington D.C.

The Washington Metro area is notorious for policy wonks, political hot air, and traffic.  Forbes has consistently placed the area on its 10 Worst Cities for Commuters list. We looked at a 15-mile commute from Fairfax, Virginia to the U.S. News offices in the city.  The commute is exactly 15 miles each way -- but those are 15 miles on a congested main corridor. In the car, this commute would cost roughly $4.64 per day, or $1,207.44 per year.

Using a combination of buses and subways, the commute costs $8.40 per day, or $2,184 per year. For this commute, it may look like public transportation is a washout -- until you think about where that money-saving car will sit all day. That's right -- parking in D.C. can cost up to $200 per month. That adds about $10 per day to the cost of driving into the city and makes public transportation look pretty good.

Los Angeles

Another city that's perennially on worst traffic lists, Los Angeles and its sprawling network of freeways can be a commuter's nightmare. We looked at a commute from Santa Monica to downtown L.A. Though this commute is only 15 miles, Google maps says it can take up to an hour and 20 minutes in traffic. Using 25 mpg combined gas mileage, this commute costs the same as the one in DC -- roughly $4.64 per day, or $1,207.44 per year. But, if there's consistently traffic, gas mileage could drop to 21 mpg, increasing commute costs to $5.52 per day or $1,437.43 per year. Hopping on the bus, however, costs only $1.75 each way -- that's $3.50 a day or $910 per year. What's even better is that the estimated time on the bus is less than estimated driving time. In L.A., it looks like public transportation is the star.

Atlanta

Atlanta is the capital of the New South -- but that also means it's the capital of congestion. Driving from the suburb of Marietta to the Coca Cola headquarters in downtown Atlanta is a straight shot down I-75. It costs drivers roughly $1,207.44 per year. On Atlanta's MARTA transit system, however, the trip is only $1.75 each way, or $910 per year. Instead of buying the world a Coke, Atlantans should stock up on bus passes.   

Chicago

Commuters who live in Lincolnwood, Illinois don't really have a direct route to downtown Chicago. That means a lot of stop-and-go city traffic -- which brings down gas mileage. At 21 mpg, this commute would cost $5.52 per day, or $1,437 per year. On Chicago Transit Authority buses and trains, however, this commute costs $2 each way.  That's $4 per day or $1,040 per year. Saving about $400 per year on commuting costs will buy a lot of deep dish pizza. 

Your Commute

It's clear that taking public transit makes economic sense for some commutes. When doing your own commuting computations, however, you can take more factors into account. If public transportation in your city is unreliable, its value decreases. By the same token, if transit doesn't run near your home or office very often, you might get stuck with inconvenient commuting times -- or with no ride home if you need to leave work suddenly.   

On the flip side, though, is the bottom line. As gas prices stay high, driving solo loses its value. If you want to cut back on your commuting costs but can't quite get yourself on the bus, check out carpooling resources in your area, or talk to your company about telecommuting options. If neither of these are options, cut your commuting costs by buying a car that gets great gas mileage. You can research the most fuel-efficient cars with the U.S. News Car rankings.