Abstract: A geographic database represents roads including an altitudinal component of the geometry of the roads. The altitudinal component of the geometry of roads is represented using data that indicate straight line segments and vertical curves, in particular parabolic vertical curves. The straight lines and vertical curves are determined by providing data, indicating the altitude at a plurality of locations along portions of roads, as an input to a Hough transform to determine the straight line segments and vertical curves that coincide with the portions of the roads vertically. Then, data that define the straight line segments and vertical curves are stored to represent the altitudinal component of the geometry of the portions of the roads in the geographic database. The altitudinal variation of roads is thus expressed in closed form. From this closed form representation, the slope or grade at any point along the road can be easily computed.

Abstract: A multi-dimensional spatial index includes at least two dimensions that define physical boundaries of the features represented by the indexed data. In addition, the multi-dimensional spatial index includes at least one additional dimension that represents another property. The other property is an orthogonal, non-spatial property. The other property may be a property of the features represented by the indexed data or the other property may be a property of the data. The other property represented by the additional dimension may include: granularity, distance, altitude, scale bounds within which each spatial entity is significant, or other property. The multi-dimensional spatial index is applicable to the storage, retrieval, visualization and traversal of spatial data sets.

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 navigation system with decryption functions. The navigation system may receive from a portable data storage medium an encrypted authentication key, an encrypted first portion of a geographic database, and an unencrypted second portion of the geographic database. The navigation system may then decrypt the encrypted authentication key so as to gain access to a set of verification information and to a decryption key for decryption of the encrypted first portion. The navigation system may then use the verification information to validate use of the database, such as by ensuring that the data storage medium is authorized to hold the database or that the navigation system is authorized to access the database. In turn, the navigation system may then use the decryption key to decrypt the encrypted first portion, so as to gain access to the database as a whole. The navigation system may then use information in the database to convert location coordinates into map information for presentation to a user.

Abstract: A system and method for mass distribution of data products, such as geographic databases. An authorization server maintains a first portion of each of several data products, and each of several data distribution terminals maintains the second portion of each data product. A user may couple a portable data storage device with a data distribution terminal and select a desired data product. The terminal may then responsively obtain from the authorization server the first portion of the selected data product and record onto the data storage device both the first portion and second portion of the data product. The user may then couple the data storage device with a machine, such as a navigation system, which may then access the data product. The authorization server may secure the first portion before sending it to the data distribution terminal. The authorization server may do so by encrypting the first portion and tying the first portion together with an authorization key.

Abstract: A navigation system determines a route between a first location on a road network and a second location in a facility off of the road network. The system composes individual guidance messages for travel along a portion of the route on the road network. A pre-composed set of guidance instructions for travel in the facility along a portion of the route off of the road network are obtained from a geographic database associated with the navigation system.

Abstract: A method for collecting data for a geographic database is disclosed. Speed and position data are collected using a plurality of mobile computing platforms moving in a geographic region. The speed and position data are analyzed to identify a location of a recurring delay point corresponding to a change in the speed. The geographic database is updated to indicate the location of the recurring delay point.

Abstract: A method for collecting geographic data for use with a navigation system identifies a pedestrian segment associated with a path. A text description of the pedestrian segment is collected. The text description includes one of a predetermined number of phrases and name of at least one feature visible from a location of the pedestrian segment. Data representing the pedestrian segment is stored in the geographic database.

Abstract: A method of operating a navigation system comprises providing an image of a geographic area through which a portion of a route between an origin and destination passes. The image is an approximate 360-degree image. The method provides a guidance information overlay on the image. The guidance information overlay may be a route highlight, a maneuver arrow, an indication of a path that has been traveled, an identification of a main route and an alternative route, and a label.

Abstract: The invention provides a method and system for providing route guidance and other information from a base unit to a remote unit in response to a request from the remote unit. A query is formatted at the remote unit, the query including the request, and is transmitted from the remote unit to the base unit. Requested route guidance information is calculated at the base unit in response to the query, using a large up-to-date database located at the base unit. A response to the query is formatted at the base unit, the response including route guidance information. The response is then transmitted from the base unit to the remote unit for display. The transmission is made in a compact form through the use of maneuver arms and combined maneuver arms and through the use of tokenized forms. A maneuver arm represents a road at an intersection, for depiction on a display, by one or two endpoint coordinates.

Abstract: A method for collecting data for a geographic database is disclosed. Speed and position data are collected using a plurality of mobile computing platforms moving in a geographic region. The speed and position data are analyzed to identify a location of a traffic sign corresponding to a change in the speed. The geographic database is updated to indicate the location of the traffic sign.

Abstract: A method for collecting geographic data for use with a navigation system is disclosed. A route between a first location and a second location is identified. Data providing directions for traveling from said first location to said second location is collected. The data providing directions is stored in a geographic database. The geographic database is provided for use with navigation related features.

Abstract: A reporting program and system for updating a master copy of a geographic database is disclosed. According to the method and system, reports are obtained that relate to data contained in a geographic database. Satellite images of the geographic locations represented by the data in the reports are obtained. The satellite images are analyzed to confirm a need to make changes to the master copy of the geographic database based on the reports. After confirming the need to make the changes, the master copy of the geographic database is updated.

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 facilitating delivery of traffic messages is disclosed. Data indicating a plurality of traffic conditions on a road network are obtained. For each of the traffic conditions, the data provides a location description. For each of the traffic conditions, the location description is converted into a location reference code assigned by a traffic message supplier. A plurality of traffic messages representing the traffic conditions is transmitted. Each of the traffic messages includes the location reference code of the traffic condition.

Abstract: A method of facilitating delivery of traffic messages is disclosed. Data indicating a plurality of traffic conditions on a road network are obtained. For each of the traffic conditions, the data provides a location description. For each of the traffic conditions, the method determines at least one broadcast service area in which the traffic condition is located. A plurality of traffic messages is transmitted. Each traffic message is associated with a broadcast service area code identifying the broadcast service area in which the traffic condition is located.

Abstract: A method for collecting geographic data for use with a navigation system is disclosed. A virtual pedestrian segment providing a path through an unorganized geographic area is identified. The unorganized geographic area lacks underlying organization into roads and paths. Data indicating a location of the virtual pedestrian segment is collected. Data representing the virtual pedestrian segment is stored in the geographic database, and the geographic database is provided for use with navigation related features.

Abstract: A method of facilitating delivery of traffic messages is disclosed. Data indicating a plurality of traffic conditions on a road network are obtained. For each of the traffic conditions, the data provides a location description. For each of the traffic conditions, the method determines at least one broadcast service area in which the traffic condition is located. A plurality of traffic messages is transmitted. Each traffic message is associated with a broadcast service area code identifying the broadcast service area in which the traffic condition is located.

Abstract: A method for operating a navigation system is disclosed. An ordered plurality of interconnected segments providing a route from an origin to a destination is obtained. A guidance message for each of the segments is formed. The step of forming the guidance message comprises determining whether to reference a previous segment and adding a reference to a current segment.

Abstract: An in-vehicle navigation system includes a receiver for receiving real-time traffic information (RTTI), a database for storing routine trip information, and a processor for running a regular route application. The regular route application includes a learning mode program and an operational mode program. The learning mode program records information regarding trips regularly taken by a vehicle and populates the database with records of routine trip information. The recorded trip information can include driver identifiers, trip departure times, origin points, destination points, dates of travel, days of travel, and route data. When the vehicle begins a new trip, the operational mode program determines whether the vehicle is engaging in a routine trip. This is accomplished by comparing current vehicle location or departure time information to routine trip information in the database.