Detroit already is a ghost town, in some ways. The downtown area is an amusement park with casinos, ballparks, people movers, etc. The next few milesw out are a burnt-over district, literally. The inner suburbs are OK, Royal Oak, Ferndale, etc, would work for a cyclist. The outer suburbs are the other type of wasteland--affluent, but with no sense of community or place, and totally unmanageable without cars. This was one of the great cities, the birthplace of the working middle class. Now it's almost dead.

And one of the all-time great ironies--it was the automobile that killed the Motor City!