I used to commute 1h40m one way, which accounted for 50mins in a train (+10min avg waiting). While I ususally did pull out my laptop, the productivity just wasn't there - I can't consistently work while groggy/vitamin-d deficient during winter mornings, or in the evening being cooked after having worked for 8 hours (I have an office job, but not programming). The seats are cramped and uncomfortable, not being able to raise my arms enough to use the keyboard without bothering the passanger next to me, so I'd have to put it away during the crowded parts of the ride, and I'd be very frustrated if the train was unusually crowded. Having your "flow" be broken by arriving at the end stop and having to rush to pack your things is awful. The only conversation someone's struck up with me was a guy who insisted he'd never understand what I was doing even if he tried.

Suffice to say, after almost two years of this, I was extremely tired and sleep deprived as this ate away at my available time more than what is reasonable. Using the time for personal projects didn't compensate for it. Never again, it's really not worth it.