The problem with a car in your situation is contextual. You are supposed to spend that 40 minutes of driving concentrating on driving. Not talking on cell phones, not texting, not talking, not even listening to music but DRIVING. The context of where you are driving "probably" changes too, highway vs. city but I'm guessing that sometimes switching your driving patterns lags a bit after you get off that highway offramp.
On a bicycle or public transportation, the context is completely different.
At the very least on a bicycle you are exercising (we can get into the difficulties later of urban riding). But there are other things, how great you feel, the fantastic views, the feelings of elation, the feelings of extreme accomplishments before the day even starts.
On public transportation you can read, operate your computer, talk to your commute neighbor or get other things done.
FWIW, I draw a 20 mile radius around my house and only look for jobs in that circle. I can figure out how to bike 40 miles a day.