Switching from car to transit commute helps even less if the transit commute is really long and inefficient. (In particular, it does nothing to help create a world where there are choices other than cars or long transit commutes. No, your husband doing it will not magically make the government realize it needs better transit options; it will at most convince them that what they have already works.)

LW if your husband is serious about this, he needs to be looking at changing either where he lives or where he works so he doesn't *have* to take several hours a day in commuting; changing to more condensed living patterns shaped by where transit actually *is* is an indispensible part of creating a world less dependent on individual cars.

Either way though, those choices are going to mean sacrifices - moving, switching to maybe a less-well-paying job, or spending hours a day on transit - and those are sacrifices that affect the whole family that he shouldn't be making on his own (and shouldn't be thinking he can make on his own!) You need to tell him that something that changes the pattern of your family life that dramatically needs to be a cooperative decision, and then talk over with him why it doesn't work for you.

If you are also serious about the importance of public transit, you should be working with him to think seriously about moving to a more transit-friendly neighborhood. And/or about taking that three hours a day of commute time and spending it on political activism instead of just sitting in a train car, which will have much more long-term usefulness.