Patent ID: 8239124
Filing Date: 2012-08-07
Classification: G08G

Abstract:
1. A method for generating traffic information to be used in a car navigation system, comprising the steps of: acquiring traffic information data including information relating to a travel time of links making up a road on a map and for acquiring map data relating to the link, said map data comprising at least information on a road type of the link; checking if a volume of the traffic information data available in is sufficient for performing a statistical estimate for the travel time; checking if the volume of traffic information data relating to links located in a target area is sufficient; and adapting a size of the target area depending on the amount of available traffic information data; and further comprising a speed processing step for determining a travel speed of a specific link by extracting and evaluating the traffic information data relating to links of the same or similar road type and being located in the same target area as the specific link; wherein in said speed processing step, if an amount of the extracted traffic information data in the target area before the size is increased or after the size is increased is sufficient, a predetermined percentile speed is selected from a distribution of speed values of the extracted traffic information data extracted from said traffic information data and relating to links of the same or similar road type and being located in the same target area as the specific link and the value of a tentative speed on the specific link is set to be equal to the value of said predetermined percentile speed, if the amount of the extracted traffic information data in the target data after the size is increased is insufficient, an average speed of the distribution of the speed values relating to the specific link located in the target area is set to be the value of the tentative speed on the specific link.