US Patent 7660666 Geographic database with detailed local data

A method is disclosed for representing locations in a geographic database in a manner that facilitates navigation and routing. A core map database includes data that represents public roads in a geographic region. Each of a plurality of location map databases includes data that represent facilities, such as businesses, stores, offices, or other places, that are physically located away from the public network and access to which requires travel on paths away from the public road network. Each of the facilities represented in the location map databases is assigned a location reference code that is associated with data from which a path connecting the facility and the public road network can be determined.