Do you carpool?

I have 2 other people in my carpool, and we may be adding a third in a few months. It is the only thing that makes the commute reasonable for me financially. It is less of a hassle than I thought it would be, and BOY do I appreciate not having to fill up every week! If you don't carpool, I'd like to know why- if everyone had just 1 carpool buddy that would reduce traffic by about 40%! We would ALL get to work sooner and home again sooner, and isn't that what we want? Less time on the roads?