Also for me, riding the bus to work is always an option. That is $3 one way. So for $6 a day I get a ride to work and back. Right now it is sort of a wash for me since I usually get 25-31 mpg when I drive to work and my job is 23 miles away so I am using just under 1 gallon of gas one way. Most days it isn't any cheaper to ride the bus. But if my next car gets worse gas mileage than I get now and or gas prices go up higher then the bus will start to look more and more appealing. Right now the bus blows, I am too tall to ever be comfortable and I have to wake up one hour early to get to work at the same time.
But if you are under 6ft tall and have a bus route as an option, it really can be pretty nice not dealing with traffic. Especially on days when it snows.