Method and system for providing bicycle information with a navigation system

A navigation system feature that provides information about bicycle traffic and/or travel by bicycle. According to one aspect of the disclosed subject matter, a navigation system uses a geographic database to provide navigation-related features, such as route calculation and route guidance, for both motorized vehicles and bicycles. When providing navigation-related features for travel by bicycle, the navigation system evaluates the road segments for suitability for travel by bicycle. According to another aspect of the disclosed subject matter, a navigation system in a motorized vehicle provides warnings about bicycle traffic around the motorized vehicle as the motorized vehicle is being driven. Using a geographic database that includes data about the locations of bicycle lanes and paths, the navigation system provides warnings as the motorized vehicle approaches a bicycle lane or path or otherwise is in proximity to a bicycle lane or path. According to another aspect, information about bicycle lanes is included in a geographic database used by a navigation system. The geographic database includes data that represent roads used by motorized vehicles. The geographic database also includes data about bicycle lanes that are located adjacent to lanes of represented roads used by motorized vehicles. The geographic database also includes data about bicycle lanes that are located separately from lanes of roads used by motorized vehicles. According to another aspect, the navigation system receives transmissions from bicycles, motorcycles, or pedestrians located in a vicinity of the vehicle and provides warnings to the vehicle driver, as appropriate.

BACKGROUND OF THE INVENTION
 The present invention relates to navigation systems that use geographic
 databases and more particularly, the present invention relates to a
 feature in a navigation system wherein a navigation system user is able to
 obtain information about actual and/or potential bicycle traffic and/or
 bicycle travel.
 Navigation systems are available that provide end users with various
 navigation-related features. Some navigation systems are installed in
 vehicles and are able to provide end users of the navigation systems (such
 as the drivers of the vehicles in which the navigation systems are
 installed) with various useful features associated with driving the
 vehicles. For example, some navigation systems are able to determine an
 optimum route to travel by roads between locations in a geographic region.
 Using input from the end user, and optionally from equipment that can
 determine one's physical location (such as a GPS system), a navigation
 system can examine various routes between two locations to determine an
 optimum route to travel from a starting location to a destination location
 in a geographic region. The navigation system may then provide the end
 user with information about the optimum route in the form of guidance that
 identifies the driving maneuvers required to be taken by the end user to
 travel from the starting location to the destination location. The
 guidance may take the form of visual and/or audio instructions that are
 provided along the way as the end user is traveling the route. Some
 navigation systems are able to show detailed maps on computer displays
 outlining routes to destinations, the types of maneuvers to be taken at
 various locations along the routes, locations of certain types of
 features, and so on.
 In order to provide these and other navigating functions, navigation
 systems use geographic data. The geographic data may be in the form of one
 or more databases that include data that represent physical features in a
 geographic region. The geographic database may include data representing
 the roads and intersections in a geographic region and also may include
 information relating to the represented roads and intersections in the
 geographic region, such as turn restrictions at intersections, speed
 limits along the roads, street names of the various roads, address ranges
 along the roads, and so on.
 Although navigation systems provide many important features, there
 continues to be room for improvements. One area in which there is room for
 improvement relates to providing guidance about and for non-motorized
 vehicles, in particular bicycles. For example, some persons may want to
 enjoy the features of a navigation system, such as route calculation and
 guidance, for travel by bicycle instead of by car. Another area in which
 there is room for improvement relates to safety considerations. When
 motorized vehicles are being driven in areas in which there are also
 bicycle lanes or bicycle paths, it would be helpful if the vehicle driver
 could be provided with warnings or other guidance about actual and/or
 potential bicycle traffic around the vehicle.
 SUMMARY OF THE INVENTION
 To address these and other objectives, the present invention comprises a
 feature for a navigation system that provides information about bicycle
 traffic and/or travel by bicycle. According to a first aspect of the
 disclosed subject matter, a navigation system uses a geographic database
 to provide navigation-related features, such as route calculation and
 route guidance, for both motorized vehicles and bicycles. When providing
 navigation-related features for travel by bicycle, the navigation system
 evaluates the road segments for suitability for travel by bicycle.
 According to another aspect of the disclosed subject matter, a navigation
 system in a motorized vehicle provides warnings about potential bicycle
 traffic around the motorized vehicle as the motorized vehicle is being
 driven. Using a geographic database that includes data about the locations
 of bicycle lanes and paths, the navigation system provides warnings as the
 motorized vehicle approaches a bicycle lane or path or otherwise is in
 proximity to a bicycle lane or path.
 The aforementioned features are enabled by another aspect of the disclosed
 subject matter. According to this latter aspect, information about bicycle
 lanes is included in a geographic database used by a navigation system.
 The geographic database includes data that represent roads used by
 motorized vehicles. The geographic database also includes data about
 bicycle lanes that are located adjacent to lanes of represented roads used
 by motorized vehicles. The geographic database also includes data about
 bicycle lanes that are located separately from lanes of roads used by
 motorized vehicles.
 According to yet another aspect of the disclosed subject matter, a receiver
 in a motorized vehicle receives signals indicating actual bicycle traffic
 around the motorized vehicle. The receiver may be included as part of a
 navigation system installed in the vehicle. Bicycles are equipped with
 transmitters that send signals indicating their presence and, optionally,
 their location. The signals sent by bicycles are received in the receiver.
 The signals received in the vehicle are the signals sent by the bicycles
 equipped with transmitters or are derived from the signals sent by the
 bicycles equipped with transmitters. The navigation system provides
 warnings to the driver of the motorized vehicle as the motorized vehicle
 approaches the location of the bicycle from which the signals were
 transmitted.
 For purposes of this disclosure, a "navigation system" is understood to
 mean a navigation system installed in a vehicle (i.e., an in-vehicle
 navigation system). A "navigation system" is also understood to mean any
 software application installed on a computer platform that provides
 navigation-related features and uses geographic data, including
 applications that are installed on personal computers, networks, portable
 electronic devices, and so on. In addition, for purposes of this
 specification, the terms "bicycle lane" and "bicycle path" will be used
 interchangeably to mean a road or portion thereof designated for use by
 bicycles.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
 I. Exemplary Navigation System Platform
 A. Overview
 Referring to FIG. 1, there is a diagram illustrating an exemplary
 embodiment of a navigation system 110. The navigation system 110 may be
 stationary or portable. In the embodiment shown in FIG. 1, the navigation
 system 110 is a portable system located in a vehicle 111, such as an
 automobile, truck, or bus. In other embodiments, the navigation system 110
 may be installed in other platforms, as explained below.
 The navigation system 110 is a combination of hardware and software
 components. The hardware components of the navigation system 110 may
 include a processor 112, memory 120, and so on. In the embodiment of FIG.
 1, the navigation system 110 also includes a positioning system 124 that
 determines the position of the vehicle 111 in which it is installed. The
 positioning system 124 may include sensors 125 or other components that
 sense the speed, orientation, direction, and so on, of the vehicle 111.
 The positioning system 124 may also include a GPS system.
 The navigation system 110 also includes a user interface 131. The user
 interface 131 includes appropriate means 127 for receiving instructions
 and/or input from an end user of the navigation system. The instruction
 receiving means 127 may include a keyboard, keypad, or other type of input
 panel 127(P), a microphone 127(M), as well as other means for accepting
 end-user input, such as voice recognition software, and so on, through
 which the end user may request navigation information and services. The
 user interface 131 also includes appropriate means 129 for providing
 information back to the end user. The information providing means 129 may
 include a display 129(D) and speakers 129(S) (including speech synthesis
 hardware and software) through which the end user can be provided with
 information and services from the navigation system 110.
 All of the components described above may be conventional (or other than
 conventional) and the manufacture and use of these components are known to
 those of skill in the art. For example, the processor 112 may be of any
 type used in navigation systems, such as 32-bit processors using a flat
 address space, such as a Hitachi SH1, an Intel 80386, an Intel 960, a
 Motorola 68020 (or other processors having similar or greater addressing
 space). Processor types other than these, as well as processors that may
 be developed in the future, are also suitable.
 B. The Geographic Database
 In order to provide navigation features to an end user, the navigation
 system 110 uses geographic data 140. The geographic data 140 includes
 information about one or more geographic regions or coverage areas. The
 geographic data 140 may be stored in the vehicle 111 or alternatively, the
 geographic data 140 may be stored remotely and made available to the
 navigation system 110 in the vehicle 111 through a wireless communication
 system which may be part of the navigation system 110. In another
 alternative, a portion of the geographic data 140 may be stored in the
 vehicle 111 and a portion of the geographic data 140 may be stored in a
 remote location and made available to the navigation system 110 in the
 vehicle 111 over a wireless communication system from the remote location.
 In the embodiment shown in FIG. 1, some or all of the geographic data 140
 are stored on a medium 132 which is located in the vehicle 111.
 Accordingly, the navigation system 110 includes a drive 114 (or other
 suitable peripheral device) into which the medium 132 can be installed and
 accessed. In one embodiment, the storage medium 132 is a CD-ROM disk. In
 another alternative embodiment, the storage medium 132 may be a PCMCIA
 card in which case the drive 114 would be substituted with a PCMCIA slot.
 Various other storage media may be used, including fixed or hard disks,
 DVD disks or other currently available storage media, as well as storage
 media that may be developed in the future.
 The geographic data 140 may take a variety of different forms. In one
 embodiment, the geographic data 140 is in the form of one or more
 computer-readable data files or databases. The geographic database
 includes data specifying the positions of the roads in the covered
 geographic region(s). The geographic database also includes data relating
 to the roads, such as restrictions on directions of travel along the roads
 (e.g., one-way streets), street addresses along the roads, street names,
 speed limits along the roads, turn restrictions at intersections, and so
 on. The geographic data 140 may also include information about points of
 interest in the geographic area, such as hotels, restaurants, museums,
 stadiums, offices, automobile dealerships, auto repair shops, etc. The
 geographic data 140 may also include information about places, such as
 cities, towns, or other communities. The geographic database 140 may
 include other kinds of data about the geographic area.
 In one embodiment, the geographic database contains a plurality of road
 segment data entities. Each road segment data entity represents a portion
 (or segment) of a navigable road in the geographic region. In one type of
 geographic database, there is at least one database entry (also referred
 to as "entity" or "record") for each represented road segment in a
 geographic region. Each physical road segment has two nodes associated
 with it, one at each of the endpoints of the road segment. In this
 embodiment, the geographic data 140 also includes a plurality of data
 entities that represent these nodes. (The terms "segment" and "node"
 represent only one terminology for describing these physical geographic
 features and other terminology for these features is intended to be
 encompassed within the scope of these concepts.)
 Data attributes are associated with each road segment data record to
 describe features or characteristics of the represented road segment. The
 various attributes associated with a road segment may be included in a
 single road segment record, or may be included in more than one type of
 record which are cross-referenced to each other.
 FIG. 2 illustrates some of the components of a road segment data entity 222
 included in the geographic data 140. The road segment entity 222 includes
 a segment ID 222(1) by which the record can be identified in the
 geographic database.
 The road segment data entity 222 may also include data 222(3) that
 indicates the maximum permitted vehicular speed of travel on the
 represented road segment record. The road segment data entity 222 may also
 include data 222(4) indicating whether the represented road segment is
 part of a controlled access road (such as an expressway), a ramp to a
 controlled access road, a bridge, a tunnel, a toll road, a ferry, and so
 on. The road segment data entity 222 may also include data 222(5) that
 indicates a rank of the represented road segment. (A rank of a road
 segment may correspond to its functional class. For example, road segments
 having a rank of "4" may include high volume, controlled access roads,
 such as expressways and freeways. Road segments having a rank of "3" may
 be high volume roads with few speed changes, but are not necessarily
 controlled access roads. The lower ranked roads handle corresponding lower
 volumes and generally have more speed changes or slower speeds. Road
 segments having a rank of "0" can handle the lowest volumes. For example,
 these may include side streets, alleyways, etc.)
 The road segment data entity 222 also includes data, 222(8)(1)(1) and
 222(8)(2)(1), identifying the endpoints of the road segment. In one
 embodiment, these data, 222(8)(1)(1) and 222(8)(2)(1), include references
 to node data entities 223(1) and 223(2) defined for the nodes
 corresponding to the endpoints of the represented road segment. By
 convention, each road segment is considered to have a "left" node and a
 "right" node. The left node may be the node having greater longitudinal
 coordinates, or in the case in which the longitudinal coordinates are the
 same, the node having the lesser latitude. (Of course, which node is
 defined as the left or right node can be alternatively defined.) Each node
 data entity 223 includes data, 223(l)(1) or 223(2)(1), identifying the
 geographic coordinates (e.g., the latitude, longitude, and optionally
 altitude) of the represented endpoint.
 Also associated with the road segment data entity 222 are data 222(8)(1)(2)
 and 222(8)(2)(2) indicating valid successor segments (if any) at each of
 the endpoints of the represented road segment. A valid successor segment
 is a road segment to which vehicular travel is legally permitted from the
 represented road segment. Also associated with the road segment data
 entity 222 are data 222(8)(1)(3) and 222(8)(2)(3) indicating invalid
 successor segments (if any) at each of the endpoints of the represented
 road segment. An invalid successor segment is a road segment to which
 vehicular travel is not legally permitted from the represented road
 segment.
 The road segment data entity 222 may also include data 222(2) that indicate
 which direction on the represented road segment each of a plurality of
 different types of vehicles (or non-vehicles) are legally permitted to
 travel. For example, with respect to automobile traffic 222(2)(1), there
 are two data fields, labeled "L/R" and "R/L." These data fields are used
 to indicate whether automobile traffic is permitted on the represented
 road segment in the direction from the left node to the right node of the
 segment and from the right node to the left node, respectively. Each of
 these data fields, "L/R" and "R/L", may be represented with a single bit.
 As shown in FIG. 2, there may be separate data fields for trucks,
 222(2)(2), bicycles 222(2)(3), pedestrians 222(2((4), and so on. In
 addition, there may be separate data fields for weight classes of trucks.
 There may also be separate fields for motorcycles, horses, skaters, etc.
 The embodiment of the road segment data record 222 shown in FIG. 2 includes
 bicycle lane/path location data 222(7). These bicycle lane/path location
 data 222(7) are discussed below.
 The road segment record 222 may also include or be associated with other
 data 222(6) that include or refer to various other attributes of the
 represented road segment, such as the street address range along the
 represented road segment, the name of the road of which the represented
 road segment is a part, the highway designation of the road of which the
 road segment is a part, and so on.
 In one embodiment, the geographic data are provided by Navigation
 Technologies Corporation of Rosemont, Ill. However it is understood that
 the inventive concepts disclosed herein are not restricted to any
 particular source of data.
 C. The Navigation Programming.
 Referring again to FIG. 1, in addition to the hardware components and
 geographic database, the navigation system 110 includes or uses navigation
 programming 228. The navigation programming 228 includes the software that
 provides for the functions and/or features performed by the navigation
 system 110. The navigation programming 228 uses the geographic data 140 in
 conjunction with input from the end user via the user interface 131, and
 possibly in conjunction with outputs from the positioning system 124, to
 provide various navigation-related features and/or functions.
 The navigation programming 228 may be stored in a non-volatile storage
 medium 229 in the navigation system 110. Alternatively, the navigation
 programming 228 and the geographic data 140 may be stored together on a
 single storage device or medium. Alternatively, the navigation programming
 228 may be located at a remote location and may be provided to or accessed
 by the navigation system 110 over a communications system.
 In one embodiment, the navigation programming 228 is written in the C
 programming language although in alternative embodiments other programming
 languages may be used, such as C++, Java, Visual Basic, and so on.
 The navigation programming 228 may be formed of separate component
 applications (also referred to as programs, subprograms, routines, or
 tools). The component applications of the navigation programming 228 work
 together through defined programming interfaces. FIG. 3 shows a block
 diagram illustrating some of the component applications for one embodiment
 of the navigation programming 228 included in the navigation system 110 of
 FIG. 1. In addition to the component programs shown in FIG. 3, the
 navigation programming 228 may include other component sub-routines or
 programs.
 In FIG. 3, the navigation programming 228 is shown to include a navigation
 application manager 240. The navigation application manager 240 is a
 program or routine that provides for overall management of the functions
 of the navigation system 110. The navigation application manager 240 may
 also include support for and interfaces to the navigation system hardware,
 such as the positioning system 124 and the user interface 131. The
 navigation application manager 240 includes user interface functions 242
 to interface with the user interface hardware 131. These user interface
 functions 242 may provide for presenting a menu to the end user on the
 screen display 129(D) of the user interface hardware 131, accepting inputs
 from the end user via the input devices 127 of the user interface hardware
 131, displaying results to the end user on the screen display 129(D) of
 the user interface hardware 131, and so on.
 The navigation programming 228 includes sub-programs or routines that
 interface with the navigation application manager 240 and that provide for
 specific navigation-related features or functions to be performed by the
 navigation system. These sub-programs include a route calculation
 application 250, a route guidance application 252, a map display
 application 253, and a map matching function 256. The navigation
 programming 228 may include navigation applications in addition to these.
 The route calculation application 250 receives a request to calculate a
 route to a desired destination. The request may be in the form of an
 identification of a starting location and a desired destination location.
 The identification of these locations may include the geographic
 coordinates of these locations. The route calculation application may also
 be provided with other data or parameters, such as driving preferences
 (e.g., avoid toll roads). Given at least the identification of a starting
 location and a desired destination location, the route calculation
 application 250 attempts to determine one or more solution routes between
 the starting location and the destination location. A solution route is
 formed of a series of connected road segments over which a vehicle can
 travel from the starting location to the destination location. When the
 route calculation application 250 calculates a route, it accesses the
 geographic data 140 and obtains road segment data entities 222 that
 represent road segments around and between the starting location and the
 destination location. The road calculation application 250 uses the
 information in the road segment data entities 222 to attempt to determine
 at least one valid solution route from the starting location to the
 destination location. In determining a valid solution route for a vehicle
 to travel, the route calculation program 250 uses the data attributes
 associated with the road segment data entities to account for direction of
 travel restrictions (e.g., one-way streets), turn restrictions at
 intersections (e.g., no left turns), and so on. The route calculation
 application 250 may attempt to find a solution route that takes the least
 time to travel, that covers the least distance, or that meets some other
 specifiable criteria.
 The route calculation application 250 may use various means or algorithms
 in determining solution routes. Methods for route calculation are
 disclosed in Ser. No. 09/047,698, Mar. 25, 1998, the entire disclosure of
 which is incorporated by reference herein. (The methods disclosed in the
 aforementioned patent application represent only some of the ways that
 routes can be calculated and the subject matter claimed herein is not
 limited to any particular method of route calculation. Any suitable route
 calculation method now known or developed in the future may be employed.)
 The route calculation application 250 provides an output. In the embodiment
 of FIG. 3, the output of the route calculation application 250 is in form
 of an ordered list 254 identifying a plurality of road segments. The
 plurality of road segments form the continuous navigable route between the
 origin and the destination that had been calculated by the route
 calculation application 250. (The route calculation application 250 may
 calculate more than one solution route.)
 The list 254 of road segments determined by the route calculation
 application 250 is provided to the route guidance application 252. The
 route guidance application 252 uses the information in the list 254, as
 well as additional information from the geographic database 140, to
 provide instructions and advice to the end user to travel the route
 defined by the list 254 output by the route calculation application 250.
 The route guidance application 252 may include functions that identify
 locations along the calculated route at which maneuvering instructions may
 be provided to the end user. The route guidance application 252 may also
 include functions that formulate the maneuvering instructions for visual
 output and/or audio output. The route guidance application 252 may provide
 the maneuvering instructions all at once, or alternatively, the route
 guidance application 252 may provide the maneuvering instructions one at a
 time as the vehicle is traveling. In one embodiment, each maneuvering
 instruction is provided separately (or in small groups of combined
 maneuvering instructions) in advance of when the specific maneuver is
 required to be taken so that the end user can prepare to make the required
 maneuver.
 In order to provide maneuvering instructions at appropriate times and/or
 locations, the navigation system 110 uses data from the positioning system
 124. The positioning system 124 determines the position of the vehicle as
 it is traveling. The map-matching application 256 in the navigation
 programming 228 compares the vehicle position determined by the
 positioning system 124 to the positions of the road segments in the
 solution driving route 254. Using this comparison, the maneuver
 instructions, which are related to positions along the solution route, can
 be provided at appropriates times as these positions are approached.
 The route guidance application 252 may also provide the end user with
 information about the remaining distance to the destination location. The
 navigation application manager 240 and the route guidance application 252
 may also use the outputs from the positioning system 124 and the
 map-matching application 256 for this purpose.
 The list 254 of road segments from the route calculation application 250
 may also be provided to the map display application 253. The map display
 application 253 uses the information in the list 254, as well as
 additional information from the geographic database 140, to provide
 graphical maps on the display (129(D) in FIG. 1) of the user interface
 131. The graphical maps illustrate the areas through which the calculated
 route passes. The path of the calculated route may be highlighted on the
 displayed maps. The map display application 253 interfaces with the
 navigation application manager 240 so that the display maps are provided
 as the vehicle is traveling the calculated route. The navigation
 application manager 240 and the map display application 253 may receive
 the outputs from the positioning system 124 and the map-matching
 application 256 for this purpose.
 II. Including Bicycle Data in Geographic Database
 As mentioned above, navigation systems can be very useful, providing end
 users with helpful navigation-related information. End users may enjoy
 even greater advantages with one or more of the embodiments disclosed
 herein. According to some of the disclosed embodiments, navigation systems
 (or navigation applications installed on other platforms) are augmented or
 enhanced by providing guidance about the presence of bicycle traffic so
 that vehicle drivers can take extra precautions. Further according to some
 of the disclosed embodiments, navigation systems (or navigation
 applications installed on other platforms) are augmented or enhanced by
 providing navigation-related features, such as route calculation and route
 guidance, for travel by bicycle.
 These features are provided in part by data included in the geographic
 database 140. Referring again to FIG. 2, bicycle data 222(2)(3) and 222(7)
 are included in some or all the data records that represent road segments.
 According to one embodiment, the bicycle data 222(2)(3) and 222(7) include
 several component items of information. (In alternative embodiments, there
 may be more or fewer than these items of information.)
 A first component of the bicycle data includes the bicycle permitted
 direction attributes 222(2)(3). The bicycle permitted direction attributes
 222(2)(3) are used to indicate whether the represented road segment
 permits bicycle traffic and which directions along the road segment
 bicycle traffic is permitted.
 The bicycle data includes the bicycle location left-to-right attribute
 222(7) "L/R" and the bicycle location right-to-left attribute 222(7)
 "R/L." These attributes 222(7) "L/R" and 222(7) "R/L" are used when a
 bicycle lane is located parallel to a lane of a road segment used by
 motorized vehicles. These attributes 222(7) "L/R" and 222(7) "R/L" are
 used to indicate on which side of a road segment the bicycle lane is
 located. (The explanation provided herein applies to geographic databases
 that represent road segments in countries in which motorized vehicles
 travel on the right-hand side of the road. In countries in which motorized
 vehicles travel on the left-hand side of the road, appropriate
 modifications would be made.)
 A bicycle lane that is parallel to a motor vehicle lane of a road segment
 is assumed to be located to the right of all the motor vehicle lanes of
 the road, i.e., toward the shoulder and away from the centerline of the
 road. The bicycle location left-to-right attribute 222(7) "L/R" is used to
 indicate that a bicycle lane is located along the side of the road segment
 to the right of the vehicle lanes (if any) that permit vehicle from the
 left node to the right node. Similarly, the bicycle location right-to-left
 attribute 222(7) "R/L" is used to indicate that a bicycle lane is located
 along the side of the road segment to the right of the vehicle lanes (if
 any) that permit vehicle from the right node to the left node. The
 attributes 222(7) "L/R" and 222(7) "R/L" are used to define the locations
 of bicycle lanes without regard to whether vehicular traffic is legally
 permitted in the direction relative to which the location of the bicycle
 lane is defined. The bicycle location left-to-right attribute 222(7) "L/R"
 is used to define the relative location of a bicycle lane even if the
 represented road segment is a one way street in which the direction of
 vehicular traffic is restricted to the direction from the right node to
 the left node. Likewise, the bicycle location right-to-left attribute
 222(7) "R/L" is used to define the relative location of a bicycle lane
 even if the represented road segment is a one way street in which the
 direction of vehicular traffic is restricted to the direction from the
 left node to the right node.
 Note that the bicycle permitted direction attributes 222(2)3) and 222(7)
 may be independent of each other. If bicycle traffic is legally permitted
 along a road in a particular direction, even if the road does not have a
 separate lane or path exclusively for bicycles, the bicycle permitted
 direction attribute 222(2)(3) is set to indicate that bicycle traffic is
 allowed for that direction. If no separate lane exclusively for bicycle
 traffic is present, the bicycle location attribute 222(7) would be set to
 negative even if bicycle traffic is permitted along the road for that
 direction (as indicated by the bicycle permitted direction attribute
 222(2)(3).
 Use of the bicycle data 222(2)(3) and 222(7) to represent roads that
 include bicycle lanes is illustrated in connection with FIGS. 4A-4D. FIGS.
 4A-4D show four different road configurations with bicycle lanes. (These
 four different road configurations are only examples and it should be
 understood that embodiments of the inventive subject matter disclosed
 herein may be used in many more different kinds of road configurations.)
 FIG. 4A shows road segments 300(1), 300(2), 300(3), 300(4), 300(5), 300(6),
 and 300(7), and intersections 302(1) and 302(2). Located along the road
 segments 300(3), 300(4), and 300(6) are bicycle lanes 306(1), 306(2), and
 306(3). In the road configuration shown in FIG. 4A, the bicycle lanes
 306(1), 306(2), and 306(3), are formed of portions of the road segments
 300(3), 300(4), and 300(6). In the geographic database 140, each of the
 road segments 300(1), 300(2), 300(3), 300(4), 300(5), 300(6), and 300(7)
 is represented by a road segment data entity (similar to the entity 222
 shown in FIG. 2). The road segment data entities 222 that represent the
 road segments 300(3), 300(4), and 300(7) include data attributes that
 indicate that a bicycle lane is associated with the represented road
 segment. For example, in the data record 222 that represents the road
 segment 300(4), the permitted bicycle direction attribute 222(2)(3) "R/L"
 is set, indicating that the road segment represented by the data entity
 permits bicycle traffic from the right node to the left node. (Note that
 motorized vehicle traffic is also permitted along the road segment 300(4)
 so the attributes 222(2)(1) "L/R" and "R/L" (for autos) and possibly
 222(2)(2) "L/R" and "R/L" (for trucks) are also set. The bicycle location
 left-to-right attribute 222(7) "L/R" is not set, indicating that the road
 segment represented by the data entity does not include a bicycle lane to
 the right of the lane(s) for motorized vehicles extending from the left
 node 302(1) to the right node 302(2). The bicycle location right-to-left
 attribute 222(7) "R/L" is set, indicating that the road segment
 represented by the data entity includes a bicycle lane to the right of the
 lane(s) for motorized vehicles from the right node 302(2) to the left node
 302(1). The bicycle data attributes 222(2)(3) and 222(7) for the data
 entities that represent the road segments 300(3) and 300(7) would be
 similarly set.
 FIG. 4B shows another configuration of road segments including a bicycle
 lane. FIG. 4B shows road segments 300(11), 300(12), 300(13), 300(14),
 300(15), 300(16), and 300(17), and intersections 302(11) and 302(12).
 Located along the road segments 300(1), 300(4), and 300(6) are bicycle
 lanes 306(11), 306(12), and 306(13). In the road configuration shown in
 FIG. 4B, the bicycle lanes 306(11), 306(12), and 306(13), are separate
 road segments that are located close to but physically apart from the road
 segments 300(13), 300(14), and 300(17). (In the embodiment shown in FIG.
 4B, two-way bicycle traffic is permitted on the bicycle path 306(11),
 306(12, and 306(13).)
 As stated above, each of the road segments 300(11), 300(12), 300(13),
 300(14), 300(15), 300(16), and 300(17) is represented by a road segment
 data entity in the geographic database 140. Even though the bicycle lanes
 306(11), 306(12), and 306(13) are located separate from the road segments
 300(13), 300(14), and 300(17), they are relatively close to these road
 segments, e.g., within the right-of-way of the road segments. Thus, these
 bicycle lanes are represented as parts of the respective road segments
 along which they located. Accordingly, the road segment data entities 222
 that represent the road segments 300(13), 300(14), and 300(17) include
 data attributes that indicate that a bicycle lane is associated with the
 represented road segment. For example, in the data record 222 that
 represents the road segment 300(14), the permitted bicycle direction
 attributes 222(2)(3) "L/R" and "R/L" are set indicating bicycle traffic is
 permitted along the road segment from the left node to the right node and
 from the right node to the left node. The bicycle location left-to-right
 attribute 222(7) "L/R" is not set, but the bicycle location right-to-left
 attribute 222(7) "R/L" is set, indicating that the road segment
 represented by the data entity includes a bicycle lane to the right of the
 lane(s) for motorized vehicles from the right node 302(12) to the left
 node 302(11). The bicycle data attributes 222(2)(3) and 222(7) for the
 data entities that represent the road segments 300(13) and 300(17) would
 be similarly set.
 FIG. 4C shows another configuration of road segments including bicycle
 lanes. FIG. 4C shows road segments 300(21), 300(22), 300(23), 300(24),
 300(25), 300(26), and 300(27), and intersections 302(21) and 302(22).
 Located along the road segments 300(23), 300(24), and 300(27) are bicycle
 lanes 306(21), 306(22), 306(23), 306(24), 306(25), and 306(26). In the
 road configuration shown in FIG. 4C, the bicycle lanes are located on both
 sides of the road segments 300(23), 300(24), and 300(27). The road segment
 data entities 222 that represent the road segments 300(23), 300(24), and
 300(27) include data attributes that indicate that a bicycle lane is
 associated with the represented road segment. For example, in the data
 record 222 that represents the road segment 300(24), the permitted bicycle
 direction attributes 222(2)(3) "L/R" and "R/L" are set indicating that
 bicycle traffic is permitted from the left node to the right node and from
 the right node to the left node. The bicycle location left-to-right
 attribute 222(7) "L/R" is set, indicating that the road segment
 represented by the data entity includes a bicycle lane to the right of the
 lane(s) for motorized vehicles from the left node 302(21) to the right
 node 302(22). Likewise, the bicycle location right-to-left attribute
 222(7) "R/L" is set, indicating that the road segment represented by the
 data entity includes a bicycle lane to the right of the lane(s) for
 motorized vehicles from the right node 302(22) to the left node 302(21).
 The bicycle data attributes 222(2)(3) and 222(7) for the data entities
 that represent the road segments 300(23) and 300(27) would be similarly
 set.
 FIG. 4D shows another configuration of road segments including bicycle
 lanes. FIG. 4D shows road segments 300(31), 300(32), 300(33), 300(34),
 300(35), 300(36), 300(37), and 300(38), and intersections 302(31) and
 302(33). A bicycle path, formed of segments 306(1) and 306(2), crosses the
 road segments 300(34) and 300(35) forming the intersection 302(32).
 Separate road segment data entities are included in the geographic
 database 140 to represent the segments, 306(1) and 306(2), that form the
 bicycle path. In the road configuration shown in FIG. 4D, the bicycle
 lanes are not associated with any particular road segments on which
 motorized vehicle traffic is permitted. In the data entities that
 represent these bicycle path road segments, the bicycle permitted
 direction attributes 222(2)(3) "L/R" and "R/L" are set, indicating that
 the road segment represented by the data entity allows bicycle traffic in
 both directions. The motorized vehicle attributes 222(2)(1) and 222(2)(2)
 are not set for these data entities since the represented road segments do
 not have lanes for motorized vehicle traffic.
 The foregoing represents one way that data about bicycle paths can be
 included in the geographic database. Other arrangements and other kinds of
 data about bicycles may be included.
 III. Using Bicycle Data in Navigation Systems
 A. Bicycle Route Calculation and Guidance.
 According to one embodiment, a navigation system can provide an end user
 with route calculation and route guidance for traveling to a desired
 destination by bicycle. According to this embodiment, the navigation
 system uses a geographic database that includes bicycle data, such as the
 geographic database described in connection with FIGS. 2 and 4A-4D.
 There are several ways that a navigation system can be used to provide
 navigation-related features for travel by bicycle. For example, some
 navigation systems are portable and can be carried by the user. With a
 portable navigation system, the user can operate the navigation system to
 calculate a route. Then, after the route has been calculated, the portable
 navigation system can be carried by the user while riding a bicycle along
 the calculated route. The portable navigation system may include mounting
 hardware so that it can be mounted on the bicycle. Alternatively, the
 portable navigation system may be strapped or otherwise fastened to the
 body of the bicyclist. Alternatively, the portable navigation system may
 be carried in a knapsack, a bicycle carrier, etc. The navigation system
 may provide guidance for following the route while the bicyclist is
 traveling along the calculated route. The guidance may be in the form of
 maneuvering instructions to follow the calculated route. The guidance may
 also include other kinds of advice. The guidance may be in visual or audio
 form.
 Another way that a navigation system that can be used to provide
 navigation-related features for traveling a route by bicycle is have the
 navigation system provide an output that is then carried by the user as
 the route is ridden by bicycle. FIG. 5 shows one example illustrating this
 embodiment. In FIG. 5, a navigation application program 400 is run on a
 personal computer 402. (The navigation application program 400 may be
 similar or identical to the navigation programming 228, described above.)
 The navigation application program 400 is used to calculate a bicycle
 route to a destination. Then, guidance 404 for following the calculated
 route is printed out and carried by the bicyclist 406 as the route is
 being driven. The guidance 404 can take the form of printed instructions
 describing the maneuvers to be taken while riding the route or can include
 one or more maps that show the bicycle route highlighted.
 In another alternative shown in FIG. 6, the navigation application 400
 provides a data output 410 that is transmitted into a portable electronic
 device 412 which is then carried by the bicyclist 406 as the route is
 being ridden. The bicyclist 406 can then obtain route guidance from the
 portable electronic device 412. The portable electronic device 412 may be
 a portable personal computer, a personal digital assistant, a
 PalmPilot.RTM.-type device, a portable navigation device, etc.
 A navigation system installed in a vehicle can also be used to provide
 route calculation and route guidance features for a bicycle route. FIG. 7
 is a diagram showing an example of this embodiment. A user who wishes to
 travel by bicycle operates the in-vehicle navigation system 110 to
 calculate a bicycle route. Then, after the in-vehicle navigation system
 110 has calculated the bicycle route, the user may copy the route guidance
 by hand 421, obtain a printed output 422 of the route guidance, or
 transmit the route guidance data to a portable electronic device 424.
 Alternatively, the user may review the route guidance on the display
 129(D) of the navigation system and commit it to memory.
 There are other ways in addition to those described above in which a
 navigation system or navigation application can be used to provide
 navigation-related functions for traveling by bicycle.
 When a navigation system is used calculate a bicycle route, several
 considerations apply. For example, when a bicycle route is requested, the
 end user may provide input indicating that the route is going to be
 traveled by bicycle. Referring to FIG. 3, an input 425 is provided to the
 navigation system 110 by the end user indicating that the route is going
 to be traveled by bicycle. The user can provide this input 425 using an
 input or setup menu provided by the user interface 131.
 After the user has requested a bicycle route to a destination, the route
 calculation application 150 determines a solution route. The route
 calculation application 250 operates in a manner similar to the manner in
 which it operates when a route for a motorized vehicle is determined with
 the following differences. First, when determining a solution route for a
 bicycle, road segments that are "bicycle only" can be used in the solution
 route. "Bicycle only" roads are those roads in which the data fields for
 permitted motorized vehicle traffic, e.g., 222(2)(1) and 222(2)(2) in FIG.
 2, are set to negative and at least one of the data fields for permitted
 bicycle traffic direction, e.g., 222(2)(3), is set on.
 Another difference that occurs in the route calculation application when
 determining a bicycle route relates to controlled access roads. If data
 222(4) in a record that represents a road segment indicates that the
 represented road segment is part of a controlled access road (e.g., an
 expressway), the represented road segment is not used in a solution route
 for a bicycle. (Note that a controlled access road segment may be
 represented by a data entity 222 in which the permitted bicycle direction
 of travel attributes 222(2)(3) "L/R" and "R/L" are both set to negative.)
 Another difference that may apply relates to valid and invalid successors.
 Because bicyclists can dismount and walk their bicycles across
 intersections, turn restrictions at intersections may not apply.
 Accordingly, when determining a solution route for a bicycle, invalid
 successors (222(8)(3)(1) and 222(8)(3)(2)) as well as valid successors
 (222(8)(3)(1) and 222(8)(3)(2)) of a segment may be used in a solution
 route.
 Another difference that applies when calculating a solution route for
 travel by bicycle is that the bicycle is assumed to travel at a speed
 appropriate for a bicycle regardless of the posted vehicle speed limit.
 Thus, the speed category or speed limit attribute (222(3) in FIG. 2) may
 not be used (except as noted below) when determining which road segments
 to include in a solution route for a bicycle because a bicycle is assumed
 to travel at the same speed along any road segment regardless of the
 posted vehicle speed. Accordingly, when determining a solution route for a
 bicycle, the shortest route may be determined as the best route.
 Although speed limits along roads may not be used to determine which road
 segments provide the fastest travel times for travel by bicycle, data
 about the speed limits along roads may be used to suppress high speed
 roads from consideration in a solution route for travel by bicycle. This
 feature is preferably optional and may be specified by the user. As
 mentioned above in connection with FIG. 2, in the geographic database, the
 data representing a road segment includes an attribute, e.g., 222(3), that
 indicates a permitted vehicle speed along the represented road segment.
 This attribute may include the actual speed limit or a speed category that
 defines ranges of speed limits. If the user specifies that high speed
 roads should not be used when calculating a bicycle route, road segments
 having high speed limits, e.g., 45 miles per hour or above, are not used
 in a solution route for a bicycle unless there is no other way to get to
 the destination.
 Another factor that can be considered when determining a solution route for
 travel by bicycle is altitude. Bicycle travel may be assumed to be
 affected by changes in altitude. By contrast, motorized vehicles may be
 assumed to be relatively unaffected by changes in altitude. As mentioned
 above, in a geographic database, the data that represent roads and other
 geographic features may include attributes that indicate the geographic
 positions of the represented features, including latitude, longitude and
 optionally altitude. Using the information in the geographic database
 about altitudes of geographic features, a solution route for travel by
 bicycle can be determined that minimizes changes in altitude (e.g.,
 minimizes hills) or avoids abrupt increases in altitude (e.g., avoids
 steep hills), etc. Alternatively, hilly roads may be preferred for
 exercise purposes and the route calculation function can be configured to
 favor such routes.
 Other differences in addition to those mentioned above may apply to the
 determination of a solution route for a bicycle. After the solution route
 for the bicycle is determined, guidance for following the calculated
 solution route is provided to the user in any of the ways described above.
 B. Bicycle Warnings While Driving
 According to another aspect of a disclosed embodiment, a navigation system
 installed in a motorized vehicle can provide guidance to the vehicle
 driver that includes warnings about bicycle traffic around the vehicle. As
 mentioned above, an in-vehicle navigation system can be used to provide
 guidance for following a calculated route. The guidance may take the form
 of visual or audio instructions that identify the maneuvers to be taken to
 drive the calculated route. These instructions may be provided as the
 route is being driven. In one embodiment, the output of the positioning
 system (124 in FIG. 1) determines the position of the vehicle in the
 geographic area. From this information, the position of the vehicle along
 the calculated route can be determined using the map matching application
 (256 in FIG. 3). Then, the maneuvering instructions can be provided in
 advance of when the maneuver has to be made by the driver. Thus, the
 driver can readily follow the maneuvering instructions to drive the
 calculated route.
 The guidance provided by the navigation system while the route is being
 driven may include information in addition to maneuvering instructions.
 The additional information may be provided for the interest of the driver.
 For example, when the vehicle passes a municipal boundary, the navigation
 system may provide the driver with a notification about the boundary
 crossing (e.g., "ENTERING WISCONSIN"). Similarly, the navigation system
 may provide guidance informing the driver when a point of interest is
 being passed.
 According to an embodiment, the navigation system provides the driver with
 information about potential and/or actual bicycle traffic. This
 information is provided for safety purposes. The information can be used
 by the driver to look out for bicycles, to slow down, honk, etc.
 Referring to FIG. 3, the information about bicycle traffic is provided by a
 bicycle warning application 400. The bicycle warning application 400 is
 part of the navigation programming 228 of the navigation system 110. The
 bicycle warning application 400 may be part of the route guidance
 application 252 or may be provided as a separate application.
 When providing information about bicycles, the bicycle warning application
 400 uses the bicycle data (222(2)(3) and 222(7) in FIG. 2) in the
 geographic database 140 to determine when a bicycle traffic warning should
 be provided. Using the output from the positioning system 124 and the
 calculated route 254, the bicycle warning application 400 can provide a
 warning when the path of the vehicle is about to cross a bicycle lane.
 Situations in which the navigation system provides warnings are described
 in the following examples.
 EXAMPLE 1
 A first example is described in connection with FIG. 8. FIG. 8 shows the
 same road configuration illustrated in FIG. 4A. In FIG. 8, the vehicle 111
 is located at a position 500 on the segment labeled 300(4) traveling
 westbound toward the intersection labeled 302(1). The vehicle 111 is
 following a route calculated by the navigation system installed in the
 vehicle 111. The calculated route calls for making a right turn at the
 intersection 302(1) from the segment 300(4) onto the segment labeled
 300(1). As the vehicle 111 approaches the intersection 302(1), the
 navigation system installed in the vehicle 111 provides route guidance in
 the form of a maneuvering instruction that informs the driver to make a
 right turn at the upcoming intersection onto the segment 300(1). According
 to a present embodiment, in conjunction with providing the route guidance
 for making the right turn, the navigation system 110 also provides a
 warning to the driver informing him/her that the vehicle will be crossing
 a bicycle lane immediately when turning onto the segment 300(1). This
 warning may be provided visually on the display screen 129(D) and/or as an
 audible warning over the speaker 129(S). An example of a warning 502
 provided on the display 129(D) of the navigation system 110 is shown in
 FIG. 9.
 EXAMPLE 2
 According to another embodiment, a warning about crossing a bicycle lane
 may be provided by the bicycle warning application 400 (of FIG. 3) even if
 the vehicle 111 is not following a calculated route. If the vehicle is not
 following a calculated route, warnings about bicycle traffic are based
 upon the present vehicle location (as determined by the positioning system
 124 and the map matching application 256) and the vehicle heading. An
 example illustrating this embodiment is shown in FIG. 10.
 FIG. 10 shows the same road configuration illustrated in FIG. 4D. In FIG.
 10, the vehicle 111 is located at a position 510 on the segment labeled
 300(35) traveling westbound. The vehicle 111 is not following a route
 calculated by the navigation system installed in the vehicle 111. However,
 using the positioning system 124 and the map matching application 256, the
 bicycle warning application 400 determines that the vehicle is approaching
 a bicycle path crossing. Accordingly, the bicycle warning application 400
 causes a warning to be provided to the driver as the location of the
 bicycle path crossing at 302(32) is approached. This warning may be
 provided visually on the display screen 129(D) and/or as an audible
 warning over the speaker 129(S). An example of a warning 512 provided on
 the display 129(D) of the navigation system 110 is shown in FIG. 11.
 According to a further aspect of this embodiment, if a driver indicates an
 intention to turn, such as by turning on the vehicle's directional signal,
 the bicycle warning application 400 immediately evaluates the bicycle lane
 location data 222(7) associated with the segment upon which the vehicle is
 traveling to determine whether a bicycle lane is located along the segment
 in the direction indicated by the vehicle's directional signal. If the
 data 222(7) indicate the presence of a bicycle lane in the signaled
 direction, the bicycle warning application 400 causes a warning, to be
 provided to the driver. The warning may be similar to the warnings shown
 in FIGS. 9 and 11.
 EXAMPLE 3
 According to another embodiment, warnings about bicycle traffic may be
 provided by the bicycle warning application 400 even if the vehicle path
 is not going to cross a bicycle path. According to this embodiment,
 warnings may be provided when the vehicle is close to a bicycle path. An
 example illustrating this embodiment is shown in FIG. 12. FIG. 12 shows
 the same road configuration illustrated in FIG. 4A and FIG. 8. In FIG. 12,
 the vehicle 111 is located at a position 520 on the segment labeled 300(4)
 traveling westbound. The vehicle 111 is following a route calculated by
 the navigation system installed in the vehicle 111. The calculated route
 calls for continuing straight at the intersection 302(1) from the segment
 300(4) onto the segment labeled 300(3). According to a present embodiment,
 the bicycle warning application 400 provides a warning to the driver
 informing him/her that the vehicle is traveling next to a bicycle path.
 This warning may be provided visually on the display screen 129(D) or as
 an audible warning over the speaker 129(S). An example of a warning 522
 provided on the display 129(D) of the navigation system 110 is shown in
 FIG. 13. This warning 522 may be provided periodically while vehicle is
 traveling next to a bicycle path.
 C. Alternative Embodiment for Providing Warnings While Driving
 According to another embodiment, an electronic device, such as a navigation
 system located or installed in a motorized vehicle, can provide warnings
 about objects actually located in the vicinity around the vehicle. The
 electronic device located or installed in the vehicle can provide these
 warnings using wireless transmissions from the objects. Included among the
 types of objects about which warnings can be provided are any slow-moving
 vehicles or objects, any fast-moving vehicles or objects, or any
 stationary vehicles or objects. For example, slow-moving vehicles may
 include bicycles, joggers, wide load trailers, etc. Fast moving vehicles
 may include ambulances, police cars, and other emergency vehicles.
 Stationary objects include stopped vehicles, construction sites, etc. An
 implementation of this alternative embodiment in connection with bicycle
 traffic is described below.
 According to this embodiment, bicycles are equipped with transmitters.
 These transmitters send signals on a regular basis, such as every 5
 seconds, every 10 seconds, etc. These signals may be relatively low
 powered so that they are transmitted over only a limited area. These
 signals may include information, such as the instantaneous geographic
 position of the bicycle. (Optionally, the signal may also include a
 bicycle ID or other data.) To provide information such as the geographic
 position, a transmitter on a bicycle may be coupled to or include a
 positioning system, such as a GPS system. Alternatively, the signals that
 are output by the transmitter on the bicycle may provide only an
 indication of the presence of a bicycle and not include any information
 indicating the geographic position.
 The vehicle includes equipment that can receive signals transmitted
 directly from the bicycle transmitters or signals derived from the signals
 transmitted by the bicycle transmitters. Upon receiving the signals, the
 equipment in the vehicle provides a warning to the vehicle driver about
 the presence of bicycles in the vicinity of the vehicle. If the signals
 received by the equipment in the vehicle include information about the
 positions of the bicycles, the warning provided to the vehicle driver can
 include information about the bicycle locations. In one embodiment, the
 equipment in the vehicle that receives the signals about bicycles located
 around the vehicle and/or that provides the warnings to the driver is part
 of or coupled to an in-vehicle navigation system. If bicycle position
 information is available, the position of the bicycle relative to the
 vehicle can be indicated by the in-vehicle navigation system. For example,
 the position of the bicycle can be displayed on a map on a display screen
 of the navigation system. If the bicycle location relative to the vehicle
 location and heading is such that there is little or no likelihood of an
 accident, the warning may be suppressed. Alternatively, those bicycles
 that are located outside of an area along a path ahead of the vehicle can
 be shown in one color (e.g., green) and those bicycles located along the
 path ahead of the vehicle can be shown in a different color (e.g., red).
 As mentioned above, some bicycles may only transmit signals indicating
 their presence and not their location. For these bicycles, a separate
 means of determining the location of the bicycle may used. For example,
 since the vehicle is usually moving relatively rapidly compared to the
 bicycle, the position of the bicycle can be determined using
 triangulation. The vehicle may include appropriate equipment for this
 purpose. (If the vehicle is not moving above a specified speed, e.g., 25
 mph, for any reason, such as a traffic jam, operation of the triangulation
 feature is suspended.) Alternatively, the transmitters on the bicycles can
 transmit signals that allow them to be located using the systems that are
 used to locate cellular phone users (or systems similar to such systems).
 With such systems, a bicycle position can be determined remotely and data
 indicating the bicycle position is transmitted (e.g., wirelessly) to the
 vehicle. In the vehicle, the data is received and used in the same manner
 as described above.
 In one embodiment, the transmitters on the bicycles are portable so that
 they can be carried by the bicyclist from one bicycle to another.
 As stated above, in alternative embodiments this warning feature may be
 used for objects other than bicycles. For example transmitters, like the
 kinds described above, can be used on joggers, pedestrians, wide load
 trailers, stopped vehicles, stationary objects, construction sites,
 motorcycles, ambulances, police cars, and other emergency vehicles.
 According to one embodiment described above, the electronic device located
 in the vehicle that receives these warning signals is a navigation system.
 In an alternative embodiment, the electronic device may be a radar
 detector or other type of electronic device capable of receiving the
 wireless transmissions.
 FIG. 18 is an illustration of a bicycle/motorcycle/pedestrian warning
 system for according this embodiment.
 Alternative Embodiments.
 In further alternative embodiments, the type of warnings provided by the
 bicycle warning application 400 may take into account the time of day,
 ambient light conditions, and weather conditions. For example, warnings
 about bicycle path crossings may be made more prominently (e.g., louder)
 in the evening or when lighting or visibility conditions are poor. In
 still further alternative embodiments, the kinds of warnings provided by
 the bicycle warning application 400 may be user configurable (e.g.,
 audible, visual, textual, etc.)
 It is intended that the foregoing detailed description be regarded as
 illustrative rather than limiting and that it is understood that the
 following claims including all equivalents are intended to define the
 scope of the invention.