I'm pretty skeptical of these types of programs, because I think they end up rewarding people who are already doing the desired activity for other reasons, while having only marginal effects on convincing the next tranche of people to try it.

Economics is about incentives, but commuting is a habit and habits are hard to change.

Irresistible force, meet immovable object.

I'm inclined to agree with Joyce. I also agree with Adam that it's about incentives -- and I don't think money is the right one.

Make it easy, convenient and social. I think those incentives would be far more resonant.

Tell me I can save a nickel and I'll tell you to go to hell. Tell me all my friends are doing it and I might give it a try.