That can be the case in trying to sell people on riding mass transit instead of driving. I have been working out of our San Francisco office all week, happily getting around the city without a car. I've been walking or talking public transit everywhere because it is cheaper, easier, and more sustainable.

Yesterday, however, I needed to go to Santa Clara (about 45 miles south of the City) for a conference, and decided to stay green and take mass transit. It took me 3 hours at a cost of $9.75 using a combination of subway, train and light rail. Compare that to about 50 minutes and $5 or so for gas (even at California prices) to drive.

As much as I support mass transit, there are limits to human endurance. We shouldn't point a sancitmonious finger at cars on the highway because the driver isn't on a bus or train if there isn't a mass transit option that can get them there in a reasonable amount of time.

Mass transit needs to provide a competitive quality of service if it is to be widely adopted. Urban planners have to keep this in mind when designing and funding mass transit systems -- do it well or don't do it. For example, trains and buses shouldn't have to stop at every block or quarter mile during rush our. We need to optimizine the schedules so that the greatest number of people can get to the their destination quickly. For more people to ride, many routes need to include express trains/or buses.

In theory mass transit is a great sustainable alternative to driving (like over the Bay area bridges), and in many cases it is. But if getting from point A to B is a grossly time consuming and expensive hassle, it's hard to argue with people who prefer to get behind the wheel.

How much would you be willing to extend your commute in order to travel sustainably? 30 percent? 50 percent? 75 percent?