100,000,000 drive alone to work every day. 45,000,000 of them are in areas with air problems. 30,000,000 of those are overweight and would like to lose weight. 15,000,000 of those people are driving second cars and are in easy biking distance of their jobs. If half of those people tried biking, it would make commute times shorter -- and lessen energy consumed and air quality damage for everyone. So what's the deal?