A town would be considered a part of New York if it is 30 minutes local rail trip away from downtown New York City or a state outside the city limits as in Urban agglomeration .
Example : if one lives a thirty minute subway trip away from downtown New York city , and officially lives in a separately-named smaller district or town , that district or town would be considered a part of the New York agglomeration.  It can also consist of legal administrative divisions where data are easily available because coming from one administrative level ( Metro Area , City , Town , County , ... ) The Greater Tokyo Area provides an example of the difficulties involved because estimates of its population vary according to how it is defined .
Urban agglomeration