A system and method are disclosed that allow a navigation system that uses a
geographic
database to also use the data in traffic messages broadcast by a traffic broadcast
system. One aspect of a present system and method includes the formation, storage,
and use of location reference data records in a geographic database used by a navigation
system. These location reference data records identify certain other kinds of data
records that represent physical geographic features, such as data records that
represent segments of roads, as being associated with certain location reference
numbers. These location reference records may be included in a geographic database
installed in the vehicle or may be provided to vehicles via a wireless communication
link. Another aspect of a present system and method includes the formation, storage,
and use of one or more indices that relate location reference numbers used by a
traffic broadcast system to location reference records in a geographic database
used by the navigation system. Another aspect of a present system and method is
the formation, storage, and use of data that identify, for each location reference
number, the immediately previous and the immediately next location reference number.
Still another aspect of a present system and method includes the programming, and
methods of use thereof, that query the geographic database and return the data
entities associated with certain identified location reference numbers.