Grand Theft Auto: Chinatown Wars is set in the GTA IV Liberty City minus Alderney (New Jersey) in 2009. Just like IV, Liberty City is a down-sized version of New York City. Boroughs include Broker (Brooklyn), Dukes (Queens), Bohan (Bronx), and Algonquin (Manhattan) plus Happiness Island (Liberty Island) complete with statue.
In addition to Alderney being omitted, the road map was simplified for ease of use. Most of the roads were made into straight grids that resemble the older top-down Grand Theft Auto games. Other parts of roads were omitted completely such as under bridges and tunnels.