Well, for me, there are a lot of factors.

1) If I leave at 5:30 AM, the car is probably the fastest, I can make it in probably 50 minutes. But I can't seem to regularly get up that early.
(tie) 1) If I get a ride to the train station from my wife, I can make it in 50 minutes
2) If I leave at 8 AM, the car is usually fastest, but sometimes I'm late due to traffic, construction, etc. So I don't do this often.
3) If I ride to the train station, it takes about an hour, but this doesn't vary with traffic or rush hour. Also, the time on the train is "free" I can sleep, read, talk to people, whatever. So this is preferable to a shorter commute by car. No risk of wear & tear on the car or car accidents.
4) If I drive during rush hour, it takes 90 minutes and I'm cranky when I get to work. This is the absolute last resort. (if I've missed my last train that will get me in on time)

To add to that, there are express trains and regular trains. So for me, it is more about how I prefer to travel than the duration of the commute.