@Metzinger @wahoonc I am also familiar with the honor system. Cleveland Ohio has recently went to the honor system on the Red Line, which was news to me. I got on the rapid and there was no fare box. I walked off thinking maybe I pay at destination..... nope. I intend to pay next time.
@Dahon.Steve Yes, the ridership increase was very dramatic and instead of being crushed by the extra riders, Hasselt simply bought more buses. It really is that simple, and much cheaper than building new roads. As far as the Yale study goes, I don't think there is a benefit when less miles are walked or biked because that means people are more sedentary and this will lead them down the path of chronic disease. The removal of cars from the road is the positive impact here. I would issue recommendations for distances easily covered by walking (<1.5mi) and cycling (<7mi) and the free buses could fill in the gaps for longer travel distances and out of town commuters.