I think it is more an implementation problem. Boston has a couple area with "free" buses, in the senses that Colleges, Hospitals and Businesses in a particular

I think it is more an implementation problem. Boston has a couple area with "free" buses, in the senses that Colleges, Hospitals and Businesses in a particular are sponsor those buses and their members ride for "free". In theory you should show your ID card, but they pick everybody. I have not seen homeless or stinky people. Maybe targeting the workforce, and workers could sponsor their family member, which will have for effect to extend the "free" ride to everyone leaving in a house with at least one person paying taxes. I don't know, part of this sound discriminating, but it ould be a start