Abstract: A method and apparatus for selecting a destination in a vehicle navigation system are described. The vehicle navigation system includes a display and a selection control. A first destination is selected from a primary list of destinations in response to a selection signal generated by the selection control. The first destination is placed on a secondary list of destinations in response to its selection. The secondary list includes previously selected destinations from the primary list. For subsequent destination selections, the primary and secondary lists are presented on the display thereby facilitating selection of destinations from both the primary and secondary lists. A feature by which the system may search for a destination across categories is also described.

Abstract: Methods and apparatus for generation of a route from a source location to a final destination are described. According to one embodiment, a two-ended search is performed based on the principles of the A* algorithm. That is, two routes are simultaneously generated, one from the source to the destination, and one from the destination to the source. According to another embodiment, a route generation algorithm determines when to stop searching for route candidates. The algorithm searches a map database for a first number of iterations thereby generating a first route candidate. After generation of the first route candidate, searching of the map database is terminated after a second number of additional iterations. A best route candidate is then selected as the route.

Abstract: A method and apparatus for determining an alternate route from a new source location located on an original route to a subsequent location on the original route using a vehicle navigation system are described. A portion of the original route to be avoided by the alternate route is determined which begins at the new source location. The portion of the original route includes a plurality of segments each of which has an original parameter associated therewith. Selected ones of the original parameters are adjusted thereby resulting in a plurality of adjusted parameters. The alternate route is then determined based in part on the adjusted parameters.

Abstract: A method and apparatus are provided for providing route guidance to a user of a vehicle navigation system. A route is generated which corresponds to a plurality of maneuvers. A warning distance is determined from a particular geographic location associated with a particular maneuver, the warning distance being based in part on a variable parameter. A maneuver instruction corresponding to the particular maneuver is then provided at the warning distance from the particular geographic location. In some embodiments, where the particular maneuver corresponds to a first junction, and a second junction similar to the first junction is within the warning distance, the warning distance is adjusted to an adjusted warning distance.

Abstract: The present invention provides a method and apparatus for generating a maneuver indication for an intersection having a turn-lane connector which is consistent with what a driver sees and expects. According to one aspect of the invention, it provides a method for providing maneuver indications to a driver for an intersection having a turn-lane connector which includes the steps of (a) determining when the intersection includes a turn-lane connector, (b) determining whether it is appropriate to collapse the turn lane into the main portion of the intersection for the purposes of generating a maneuver indication, (c) collapsing the turn lane into the intersection when it is appropriate, (d) generating a maneuver indication for the collapsed intersection, and (e) outputting the maneuver indication to the user in time so that the driver may use the turn-lane connector if desired.

Abstract: A method and apparatus for selecting a destination in a vehicle navigation system are described. The vehicle navigation system includes a display and a selection control. A first destination is selected from a primary list of destinations in response to a selection signal generated by the selection control. The first destination is placed on a secondary list of destinations in response to its selection. The secondary list includes previously selected destinations from the primary list. For subsequent destination selections, the primary and secondary lists are presented on the display thereby facilitating selection of destinations from both the primary and secondary lists. A feature by which the system may search for a destination across categories is also described.

Abstract: A method and apparatus for selecting a destination in a vehicle navigation system are described. The vehicle navigation system includes a display and a selection control. A first destination is selected from a primary list of destinations in response to a selection signal generated by the selection control. The first destination is placed on a secondary list of destinations in response to its selection. The secondary list includes previously selected destinations from the primary list. For subsequent destination selections, the primary and secondary lists are presented on the display thereby facilitating selection of destinations from both the primary and secondary lists. A feature by which the system may search for a destination across categories is also described.

Abstract: A method for navigating with a vehicle navigation system using recognition of geographical region types in a map database. The system's map database stores information representative of a plurality of geographical region types. A geographical region type of a geographical region in which the navigation algorithm is operating is determined. At least one parameter related to the navigation algorithm is then set to correspond to the geographical region type. Navigation is performed using the navigation algorithm. Throughout the operation of the navigation algorithm, the system repeatedly determines whether the geographical region type has changed, and if so, changes the algorithm parameter(s) to correspond to the new geographical region type.

Abstract: Method and apparatus for determining a route from a source location to a final destination using a vehicle navigation system having a map database. At least one intermediate destination is determined from the map database, each intermediate destination being at the other end of an intermediate route from the source location. A cost value is calculated for each intermediate destination. A best intermediate destination is selected from the at least one intermediate destination, the cost value corresponding to the best intermediate destination being lower than the cost values corresponding to any other intermediate destinations. The intermediate route corresponding to the best intermediate destination is then communicated to the user of the vehicle navigation system while a remainder route to the final destination is determined.

Abstract: A method and apparatus is described for selecting an entry stored in a data processing system, and specifically a destination in a vehicle navigation system. The system includes a display, a scrolling control having first and second controls, and a selecting control. Using the scrolling control, the user of the system scrolls through a plurality of stored destinations on the display. Each destination is made up of a plurality of alphanumeric symbols, the destinations forming an alphabetically and numerically organized list. The scrolling is accomplished by using the first control of the scrolling control. A character position selector is used to select a character position in a first indicated destination and the second control of the scrolling control is used to jump to subsets of destinations with the next or previous character position as compared to a currently indicated destination. The selecting control is then used to enter a desired destination.

Abstract: A vehicle navigation system displays arrow icons to a driver indicating the directions he must follow from each of one or more turning points on his route to keep the driver from passing inadvertently an intersection in which he must change the vehicle's direction of advance or from turning in an intersection prior to the intersection previously chosen for a turn. Road anomalies, such as sharp curves or U turns are also displayed. The arrow icons are alternatively created from computed directions of the vehicle's advance or stored in an X-Y storage unit from which an arrow icon best fitting the required guidance is selected. The stored arrow icons include straight road, single turns, and multiple turns. The selected arrow is displayed to the driver. An embodiment calculates turns and curves with angles which match the actual angles of the turns, and radii and turning angles of curves.

Abstract: A vehicle navigation system guides a driver along an optimal route from a starting point to a destination, either of which can be specified in categorical terms. That is, the starting point need not be on a road, and the categorical destination can be entered as "nearest gas station" or "closest hardware store." The system selects a number of possible destinations that conform to the driver's specifications and computes, simultaneously for each particular area on a digitally-stored map, possible optimal routes from the vehicle's current position to each possible destination. The optimal route is selected according to conditions of shortest distance, fastest time, or fewest turns set individually or in any combination by the driver, who is guided along the optimal route by messages on a display. A similar procedure, in which a plurality of possible starting points is proposed, yields the optimal route to a destination from an indefinitely specified starting point.

Abstract: A method for identifying highway access ramps in a database medium for use as locations for route calculation. Initially, first road segments which belong to a highway and which are connected to at least one access ramp are identified. The first road segments are sorted according to the highway to which they belong. A highway direction is determined for each first road segment. The first road segments belonging to a first highway are sorted according to highway direction. The first road segments belonging to the first highway and of each highway direction are sorted according to position, thereby forming a highway segment list for each direction of the first highway. Highway access ramps are identified for each first road segment in the highway segment list. The locations for the highway access ramps are stored in the database medium. Highway access ramps are identified in this manner for each highway in the database medium.

Abstract: In a vehicle navigation system having memory for storing road map information, calculating unit for calculating the optimum route from a given initial location to the destination and display device for sequentially displaying the directions in which the vehicle operator should drive to follow the route, the system comprises a command unit for commanding the calculating unit to recalculate the route when the vehicle deviates from the route and halt/resume unit for halting and resuming the operation of the calculating unit. When the operator decides to make a temporary deviation from the calculated route, he can use the halt/resume unit to prevent the system from recalculating the route when he leaves it and then can use it again to restart the route guidance when he return to it. This prevents unnecessary calculations from being made.

Abstract: A vehicle navigation system computes an optimal route for a journey. When the system detects that a vehicle has deviated from the optimal route, information that tells the driver of the deviation of the vehicle is displayed. When the driver turns on a recomputation command switch after reading the information, a new optimal route is computed, with the vehicle's present location as the new starting point. If the vehicle deviates again after computation of the new optimal route, another new optimal route is automatically recomputed, again with the vehicle's present location as the new starting point. The driver is thus freed from having to initiate the recomputation manually.

Abstract: When a vehicle has deviated from a computer-determined optimal route from a starting point to a destination, a navigation system warns the vehicle driver that he is off the optimal route, picks an appropriate direction for continued travel, selects a new starting point, and computes a new optimal route from the new starting point to the destination. By selecting the new starting point based on the vehicle's present location and the time to recompute a new optimal route, the system eliminates the necessity for a driver either to go back to the original optimal route, to recompute the optimal route by a manual operation, or to recompute a new optimal route more than once.

Abstract: A vehicle navigation system computes an optimal route from stored map data. Where the vehicle deviates from the optimal route, either by mistake or by choice, the driver can command computation of a new optimal route. The driver may choose whether or not to permit U-turns on the new route, thereby insuring that the original optimal route will not be retraced if his deviation was deliberate. Route guidance, deviation, and U-turn selection information is displayed to help the driver follow the original optimal route, to command computation of a new optimal route, and to choose whether or not to permit U-turns along the new optimal route.

Abstract: A navigation system prevents a vehicle from deviating from a new optimal route immediately after the new optimal route has been computed following the first deviation of the vehicle from an original optimal route. The system does this by determining the present location of the vehicle and searching road network data in a map database for a plurality of locations that are farther away from the present location than a distance travelled by the vehicle during recomputation of a new optimal route. These locations are selected as candidate new starting points. Then the system recomputes an optimal route from each of the candidate starting points to the destination. After the recomputation, the present location of the vehicle is read into the system, and an optimal route from the present location to each candidate starting point is computed.

Abstract: Where a vehicle deviates from a calculated optimal route, the system displays a message indicating the vehicle's deviation. The driver of the vehicle commands computation of a new optimum route. The system selects a new starting point from a point substantially ahead of the vehicle, recomputes the optimal route, and determines the route from the new starting point to the destination. The new starting point is far enough ahead of the vehicle to ensure that the route computation is completed before the vehicle reaches it. This prevents overrunning the new starting point before the calculation of a new optimum route is completed. Navigation guidance, computed for the new optimal route, is then displayed.