METHOD FOR IDENTIFYING HIGHWAY ACCESS RAMPS FOR ROUTE CALCULATION IN A VEHICLE NAVIGATION SYSTEM

摘要

A method for identifying highway access ramps in adatabase medium for use as locations for route calculation.Initially, first road segments which belong to a highway andwhich are connected to at least one access ramp areidentified. The first road segments are sorted according tothe highway to which they belong. A highway direction isdetermined for each first road segment. The first roadsegments belonging to a first highway are sorted according tohighway direction. The first road segments belonging to thefirst highway and of each highway direction are sortedaccording to position, thereby forming a highway segment listfor each direction of the first highway. Highway access rampsare identified for each first road segment in the highwaysegment list. The locations for the highway access ramps arestored in the database medium. Highway access ramps areidentified in this manner for each highway in the databasemedium. A method and apparatus for determining a route from astarting vehicle position to a destination using a vehiclenavigation system are also provided.