I have a public transit commute, but at the end of the day it's 8 minutes of walking to the train, a transfer after 7 minutes, and then a 7 minute walk to the office from the train. Never enough unbroken time to get into a book :(. I've learned something new about public transit commuting--look for a commute with as long a single stint on the train as possible, while still trying to minimize total time.