Patent ID: 8466810

Claim:
A method for making a database that represents a road network in a geographic region, the method comprising: using data contained in the database to identify locations at which a combination of conditions that when present together are potentially hazardous, wherein the combination of conditions comprises road intersections located at bottoms of hills throughout the geographic region, wherein the step of using data includes: selecting from the database a data record that represents a road segment; and upon determining that the road segment is part of a hill, obtaining data that represent road segments that connect to a downhill end of the road segment; and upon determining that the road segment and those road segments that connect thereto at the downhill end form an intersection located at a hill bottom, adding precautionary action data to the database to indicate potentially hazardous locations at which a precautionary action is to be taken by a vehicle system when approaching, wherein the potentially hazardous location associated with the precautionary action data comprises a road intersection located at a bottom of a hill.