I work with a group of environmentalists, and I criticize them for the times they drive their cars into work.
You're missing my point. That external factors can only have so much impact on your life. To a certain extent, if you're driving a car to and from work, then there's yourself to hold at fault, via laziness, ignorance or possibly by ignorance by culture of victimhood (aka It's not my fault, it's my situation's). If you're as environmentally minded as you posit, then you should be complaining about the traffic lights that prevent you from getting your morning exercise in; when you drive three quarters of the way to work and walk the last mile that is. I can guarantee you that there are people in the same situation as you who take your situation and choose to bike it, walk it, or hell, even carpool it.
If you've been to Europe, there's lots of exemplars walking around for you. You see old ladies scootering (not the motorized kind) into work, with a briefcase tossed over one handlebar.
I suppose I will take your bait, though I am guessing (seeing as you keep claiming that "I don't know you") that it is a job that makes you feel good about your contribution to the planet, thus enabling you to drive around without feeling too much guilt. What is it that you do?