A train ride is easier on you than a drive in traffic. He probably naps on the ride home.
My previous, shorter, commute required a line change so I was only on each train for about 5-10 minutes. My new commute is all on one line for at least 30 minutes (and more often 45+). So I have more than tripled my time on the train, and I think it is precisely this that makes me get to the end of the commute feeling so much more tired.