There are lots of homeless in San Diego and LA, however, they don't have the same level of density that SF is nor the same level of social services. >I don't t

There are lots of homeless in San Diego and LA, however, they don't have the same level of density that SF is nor the same level of social services. >I don't think most addicts or mentally disabled people have the wherewithal to make a move from, say, Chicago to SF. There is a distinction between people with mental health problems and mental disability. Things like addiction and mental health exist on a pretty vast spectrum and have massive variations day to day. As to how homeless people get around - well I see you haven't been on the greyhound much but that's a major way to travel for homeless both with their own money or with tickets paid for by various cities.