I need to go from Washington D.C. to Los Angeles, what’s is the most environmentally friendly way of doing so? Both are about the same price, either I pay for the airline ticket or I pay for the gas. But, if my car gets about 25mpg (highway), is it “greener” to fly commercially, sharing the Carbon footprint with 250 other people in the plane, or to drive by myself, maybe with a friend?

Thanks