Abstract: Systems, methods, and apparatuses are described for determining turn lane data from probe data. Probe data for an intersection including locations and headings is identified. The probe data for the intersection is divided into a first trace and a second trace based on locations. The difference in the headings, heading change data, is calculated. From the heading change data, at least two local extrema points are identified. A characteristic of the turning lane is determined based on the at least two local extrema points.

Abstract: An approach is provided for determining map matching quality using binary classification. The approach, for example, involves processing probe trajectory data using a map matcher to generate a map-matched output. The approach also involves comparing the map-matched output for a probe point of the probe trajectory data against ground truth map-matched data for the probe trajectory data to classify the probe point according to one or more binary classifications. The one or more binary classifications indicate a correctness or an incorrectness of matching with respect to the ground truth map-matched data. The approach further involves computing the map matching quality of the map matcher based on the one or more binary classifications.

Abstract: In one embodiment, the position of a mobile device is determined based, at least on part, of the relative locations of two or more nearby points. Distance data, received from a range finding sensor, corresponds to distances to the two or more nearby points from the mobile device. A predetermined model that includes previously recorded locations for objects is accessed to receive location data for two or more nearby points. A position of the mobile device is calculated based on the location data and the distance data. The nearby points may be building edges or building corners. The calculation may involve a series of equations. The series of equations may include satellite-based positioning equations in addition to equations based on the predetermined model.

Abstract: Systems, methods, and apparatuses are described for determining turn lane data from probe data. Probe data for an intersection including locations and headings is identified. The probe data for the intersection is divided into a first trace and a second trace based on locations. The difference in the headings, heading change data, is calculated. From the heading change data, at least two local extrema points are identified. A characteristic of the turning lane is determined based on the at least two local extrema points.

Abstract: Systems, methods, and apparatuses are described for determining turn lane data from probe data. Probe data for an intersection including locations and headings is identified. The probe data for the intersection is divided into a first trace and a second trace based on locations. The difference in the headings, heading change data, is calculated. From the heading change data, at least two local extrema points are identified. A characteristic of the turning lane is determined based on the at least two local extrema points.

Abstract: Systems, methods, and apparatuses are described for determining turn lane data from probe data. Probe data for an intersection including locations and headings is identified. The probe data for the intersection is divided into a first trace and a second trace based on locations. The difference in the headings, heading change data, is calculated. From the heading change data, at least two local extrema points are identified. A characteristic of the turning lane is determined based on the at least two local extrema points.

Abstract: In one embodiment, the position of a mobile device is determined based, at least on part, of the relative locations of two or more nearby points. Distance data, received from a range finding sensor, corresponds to distances to the two or more nearby points from the mobile device. A predetermined model that includes previously recorded locations for objects is accessed to receive location data for two or more nearby points. A position of the mobile device is calculated based on the location data and the distance data. The nearby points may be building edges or building corners. The calculation may involve a series of equations. The series of equations may include satellite-based positioning equations in addition to equations based on the predetermined model.

Abstract: A method is disclosed for developing traffic messages. The method obtains traffic data indicating collected traffic speeds at various locations on a road network. Traffic messages are developed from the traffic data. The method obtains ground truth data indicating ground truth speeds at a subset of the locations on the road network. The ground truth speed represents average speed of vehicles at one of the locations. For those locations for which ground truth speed has been obtained, the method computes a traffic quality value comparing the collected traffic speed to the ground truth speed for the location. The traffic messages and traffic quality data representative of the traffic quality values are transmitted.

Abstract: A method is disclosed for developing traffic messages. The method obtains traffic data indicating collected traffic speeds at various locations on a road network. Traffic messages are developed from the traffic data. The method obtains ground truth data indicating ground truth speeds at a subset of the locations on the road network. The ground truth speed represents average speed of vehicles at one of the locations. For those locations for which ground truth speed has been obtained, the method computes a traffic quality value comparing the collected traffic speed to the ground truth speed for the location. The traffic messages and traffic quality data representative of the traffic quality values are transmitted.

Abstract: A method is disclosed for developing traffic messages. The method obtains traffic data indicating collected traffic speeds at various locations on a road network. Traffic messages are developed from the traffic data. The method obtains ground truth data indicating ground truth speeds at a subset of the locations on the road network. The ground truth speed represents average speed of vehicles at one of the locations. For those locations for which ground truth speed has been obtained, the method computes a traffic quality value comparing the collected traffic speed to the ground truth speed for the location. The traffic messages and traffic quality data representative of the traffic quality values are transmitted.

Abstract: A method of obtaining data for a geographic database is disclosed. Data indicating a plurality of locations along roads including data indicating altitudes at the plurality of locations is provided. Road grade values for a plurality of subsections of the road are computed; each of the subsections is a portion of the road between two of the locations. A plurality of temporary change points are identified as joining two adjacent subsections having road grade values that differ by a value greater than a predetermined amount. Road grade values for each part of the road between adjacent temporary change points are computed. Consecutive parts of the road having road grade values that falls within a predetermined range are grouped into at least one constant road grade section. The geographic database stores data that define the constant road grade section.

Abstract: A method is disclosed for collecting traffic information using probe vehicles that are driven along roads in a geographic area. In each of the probe vehicles, the vehicle speed and the location reference code that represents that portion of the road network upon which the vehicle is located are determined. The probe vehicle transmits data that indicates the location reference code and the vehicle speed for the location reference code to a central traffic facility.

Abstract: A method for collecting data for a geographic database is disclosed. Altitude data are collected using a vehicle traveling in a geographic region. A barometer associated with the vehicle supplies the altitude data. Road grade data along the roads traveled by the vehicle is derived by analyzing the altitude data. The geographic database is updated to indicate the road grade.

Abstract: A method of obtaining data for a geographic database is disclosed. Data indicating a plurality of locations along roads including data indicating altitudes at the plurality of locations is provided. Road grade values for a plurality of subsections of the road are computed; each of the subsections is a portion of the road between two of the locations. A plurality of temporary change points are identified as joining two adjacent subsections having road grade values that differ by a value greater than a predetermined amount. Road grade values for each part of the road between adjacent temporary change points are computed. Consecutive parts of the road having road grade values that falls within a predetermined range are grouped into at least one constant road grade section. The geographic database stores data that define the constant road grade section.

Abstract: A method of obtaining data for a geographic database is disclosed. Data indicating a plurality of locations along roads including data indicating altitudes at the plurality of locations is provided. Road grade values for a plurality of subsections of the road are computed; each of the subsections is a portion of the road between two of the locations. A plurality of temporary change points are identified as joining two adjacent subsections having road grade values that differ by a value greater than a predetermined amount. Road grade values for each part of the road between adjacent temporary change points are computed. Consecutive parts of the road having road grade values that falls within a predetermined range are grouped into at least one constant road grade section. The geographic database stores data that define the constant road grade section.