Method and system for route calculation that avoids railroad crossings
View Patent ↗A navigation system provides information about railroad crossing locations. A geographic database used by the navigation system includes data that indicate whether an at-grade railroad crossing is located along a road segment. Using this information, a route calculation function in the navigation system calculates a route to a destination that avoids road segments that have at-grade railroad crossings. In this way, the delays associated with waiting for a train to cross a road are avoided.
1. A geographic database that represents road segments, the geographic database comprising:
data entities that represent road segments;
wherein each data entity that represents a road segment that has an at-grade railroad crossing located thereon includes data indicating the at-grade railroad crossing and the location thereof along the road segment.
2. The geographic database of claim 1 wherein each data entity that represents a road segment that has an at-grade railroad crossing located thereon is associated with data that indicates a relative amount of train traffic activity at the at-grade railroad crossing on the represented road segment.
3. The geographic database of claim 1 wherein each data entity that represents a road segment that has an at-grade railroad crossing located thereon is associated with data that indicates times of day associated with levels of train traffic.
4. The geographic database of claim 1 wherein each data entity that represents a road segment that has an at-grade railroad crossing located thereon is associated with data that indicates days of week associated with levels of train traffic.
5. The geographic database of claim 1 further comprising:
train schedule information, wherein each data entity that represents a road segment that has an at-grade railroad crossing located thereon refers to the train schedule information for an indication of train traffic at the at-grade railroad crossing on the represented road segment.
6. The geographic database of claim 1 further comprising:
a table of train traffic activity combinations, wherein each data entity that represents a road segment that has an at-grade railroad crossing located thereon refers to the table of train traffic activity combinations for an indication of train traffic at the at-grade railroad crossing on the represented road segment.