Navigation Technologies Corporation

Navteq North America, LLC

Yaoguang Wang

William McDonough

Oleg Voloshin

Asta Khavakh

David S Lampert

Shashi Jasthi

A method for route calculation using real time traffic conditions is disclosed. A transmission that includes weightings indicative of traffic conditions on roads is received. Then, a solution route is calculated by forming a list of road segments. The list is formed by expanding a search tree comprised of gates. Each gate represents a physical location on a road segment and an accessible direction relative thereto. Each gate to which a weighting applies is incremented by an amount indicated in the transmission. The solution route is determined by expanding the search tree, which includes determining and evaluating successor gates.

Method and system for route calculation in a navigation application

A program and method for route calculation for use with a navigation system and used with a map database that represents a road network in a geographic region. A route calculation program is adapted to find at least one solution route between a first location on a road network and a second location on the road network. The route calculation program includes a first search tree associated with the first location and a second search tree associated with the second location. Each search tree is adapted to hold gates. Each of the gates represents a physical position on the road network and a direction from the position to another location along a path on the road network. The route calculation program also includes at least one priority queue associated with one of the search trees. The priority queue assigns a priority to one of the gates in the associated search tree based upon an evaluation using a search algorithm. The gate identified as having a higher priority than any other gate in its respective search tree is expanded to determine one or more successor gates thereof. Each of these successor gates so formed is compared to the gates in the other search tree. The process of growing at least one of the search trees by expanding the gate in the search tree that has a higher priority than any other gate in the search tree is continued until a gate in one search tree corresponds to at least one gate in the other search tree.

A text placement program is disclosed. The text placement program provides for placement of text, such as names of geographic features, on a map image. A plurality of candidate locations for text placement are identified and provided to the text placement program. The text placement program evaluates each candidate location for text placement using an expression that includes a weighted clause of a first type indicative of whether the represented geographic feature is named at least once on the map image. If a candidate location being evaluated for text placement overlaps another candidate location, the expression for the candidate location being evaluated includes a weighted clause of a second type. One additional weighted clause of the second type is included for each occurrence of the candidate location overlapping another candidate location. For each candidate location, the text placement program evaluates the expression for two conditions: placement of text and no placement. The results of the two evaluations of the expression are compared and the condition that provides the greater result is selected. Optionally, the expression may include an additional weighted clause including a rank assigned to the represented geographic feature. The text placement program can be configured by adjusting the weightings assigned to the clause(s) of which it is formed.

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Rosemont, IL, United States of America

Yaoguang Wang