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.