Right now I live a 10-minute walk away from where I work.

In order to be "Green" or whatever you call it, I usually take our Work shuttle from near my home on Mon, Tues, and Thurs.  I work from home on Wed, and I drive in on Fridays.

So I only single occupancy it one or two days a week.  It saves quite a bit on gas and I feel a little good about cutting down on emissions. :)

-------
I've got spurs that jingle jangle jingle.
As I go riding merrily along.
And they sing, "Oh, ain't you glad you're single?"
And that song ain't so very far from wrong.