Setting: Rochester and New York City, New York, US, near future. Not sure it's researchable, I don't know how, at least.
Our Heroine grew up in Rochester, then ran away to New York City when she was 12. She hitchhiked from Rochester to NYC, got mugged, then met a homeless ex-military pickpocket who took her back to where he was staying.
Whereish in (or near) Rochester might a drug-addicted prostitute (her mother) and a slightly crazy, very poor old woman (her neighbor and de facto guardian) live? ("Downtown" or "The east side" or whatever is more than enough for my purposes here)
Whereish in NYC works for the second part of the scenario? I need all of the following, within at least halfway reasonable (sequential) walking distance of one another: 1. Someplace that a driver arriving in the city from out of town would be likely to go, or at least pass by, 2. Someplace that a child could be mugged (likely by a teenager) in the middle of the afternoon without arousing undue general outcry, 3. A place that a pickpocket might be trying to ply his trade (a street name or other identifier would be helpful here, however an actual resident would refer to the general area--for example, "on 5th Street" or "in Times Square" or "near Central Park"), and 4. A place that a homeless guy might sleep at night, in early fall.
edit: First bit's answered, thanks. For logistical reasons, I don't think the subway would work for anything but the last bit.