Mechanical engineering undergraduate senior here. I've been riding since the beginning of summer class. I usually cover about 6 miles round trip, depending on the route I take and the errands I run. I have a vehicle, I just choose to not deal with parking, fuel use, or the ticket writing nazis. It's actually been really beneficial for me--there's a grocery store just off from campus, the weather is generally pretty cooperative, and most of the students who live off campus live close enough to walk, so motorists (except for a few of those who have Greek-lettered license plates) are mindful of pedestrians and cyclists. It's really a nice place to ride a bike.

Hell--I've even lost a little weight doing this cycling thing.