I began riding to save money ($4.50 / day parking at metro). Once the money was not as big an issue, I kept riding for exercise (although I gained some weight over this winter, I'm still over 20 lbs lighter than I was 3 years ago). What keeps me motivated, though, is fun (I am in so much better spirits on the days I ride the bike).

I average 2-3 days a week, about 30-40 miles (depending on route) daily round trip and I ride at least 1 day a week year round, but I freely admit that I avoid riding in rain when I can help it.