After a week of hauling my bike a part of the way to work and riding the rest, I finally worked up the guts to commute the full 13 miles. I was worried about a fairly busy 1/2 mile stretch of road, but didn't have any problems on the way in. We'll see how it goes on the way home. I have to say that once I get to work after riding, I have much more energy than when I drove, not less.