I went to the Philadelphia Bike Share Forum last night and learned of some interesting stats from cities that have bike share program in place..

When there are cyclist in traffic flow, bicycle accident rate tend to go down dramatically. when # of cyclist double in large cities like Paris or Lyon, bicycle accident rate went down 80%.

Most common reason for cummuters not riding their bicycles is that they are afraid of getting hit by a car, second reason: don't want to get bike stolen.