Do you know what it really costs to drive your vehicle to and from work every day? There are a lot more costs than gas and oil when it comes to vehicle ownership, such as depreciation, insurance, taxes, etc. Even if you are a transit user, you are probably going to own a vehicle anyway, but you might be able to get more years out of your car or truck, or cut back your vehicle ownership from two cars per household to just one, or from two down to three. When you make these kind of cuts, the savings really start to add up.
The American Automobile Association (AAA) publishes a brochure on the cost of driving. You can download the 2009 Edition of this (the most current edition) by clicking here.
Balance the cost of riding transit at a few dollars a day (or less) against the cost of vehicle ownership, or at the very least, filling your tank week after week.