Abstract:
The present invention&#39;s network-based directions-provision methodology typically features the establishment of two ranking schemes that reversely parallel each other. The “personal” ranking scheme ranks all permitted persons in terms of the degree of access permission with respect to the variously ranked regions of a facility; the lower the personal rank, the fewer the regional ranks to which the person is permitted access. The “regional” ranking scheme ranks all accessible regions in terms of the degree of access permission with respect thereto by the variously ranked permitted persons; the higher the regional rank, the fewer the personal ranks that are permitted access to the region. According to typical inventive practice, a permitted person logs in to request directions, within the facility, from an original location to a destination location; the directions given (textual and/or graphical) are the optimal directions that are consistent with the personal rank of the requestor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. nonprovisional patent application Ser. No. 11/193,657, filing date 27 Jul. 2005, now U.S. Pat. No. 7,761,226, issue date 20 Jul. 2010, hereby incorporated herein by reference, entitled “Interactive Pedestrian Routing System,” sole inventor Fazal A. Rashid. 
    
    
     STATEMENT OF GOVERNMENT INTEREST 
     The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to travel routes, more particularly to methodologies for providing directions for traveling within a place or premises. 
     According to current U.S. Navy practice, when a new sailor reports aboard a ship, he or she is assigned a designee (sometimes referred to as a “sponsor”) to facilitate acclimation of the new sailor to his or her new surroundings. The sponsor typically is of the same “rate” as the new sailor, and may also work in the same division or workspace as the new sailor. Notwithstanding the effectiveness of the current system of orienting and indoctrinating new sailors, in which a sponsor personally takes a new sailor under the sponsor&#39;s wing, the current system can also result in wasted manpower. During the period of orientation and indoctrination, which may run well over a month, the sponsor may spend large amounts of time guiding and mentoring the sailor. While some of this time is time well spent, a significant portion of this time is time wasted—time that would be better spent by the sponsor on his or her other responsibilities. Each man-hour spent in new sailor indoctrination-orientation constitutes a man-hour away from the primary duty station. Furthermore, decreases in time that sponsors spend on particular tasks tend to necessitate increases in time that other personnel spend on such tasks. 
     A naval ship is large, complex and populous facility containing numerous areas and spaces. At any time onboard the ship, many pedestrians are negotiating the areas and spaces in order to get from one location to another. Navigating the labyrinthic interior of the ship can be difficult for sailors who are unfamiliar with the ship, and is often no simple matter even for sailors who are familiar with the ship. Common time-inefficient endeavors for sponsors involve directing and/or accompanying new sailors between various locations onboard the ship. In addition to Navy sailors, various other categories of people (e.g., non-Navy military personnel, government civilian employee personnel, government contractor personnel), on temporary onboard assignment, may require navigational assistance. Similar considerations as discussed hereinabove with regard to ships may apply to land-based facilities such as buildings, installations, complexes and stadiums. The desirability is manifest for a methodology of facilitating travel of an unacclimated person from one location to another in the confines of a ship or other facility without unduly occupying an acclimated person&#39;s time. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to provide method, system and computer program product for directing people who require pedestrian travel routing between various locations within a facility such as a ship. 
     According to typical inventive practice, a method for determining a route in a facility comprises: (a) providing a database that includes plural persons that are permitted to occupy a facility and plural regions that are accessible in the facility; and, (b) based on the database, determining a path for a person from a first location of the facility to a second location of the facility. In the database, each person has associated therewith a personal clearance level; each region has associated therewith a regional clearance level. There are plural personal clearance levels corresponding to plural regional clearance levels. Each regional clearance level represents the minimum personal clearance level that is permitted access to the region with which the regional clearance level is associated. Each personal clearance level represents the maximum regional clearance level to which is permitted access the person with which the personal clearance level is associated. Associated with every region that the path at least partially intersects is a regional clearance level that is no greater than the personal clearance level associated with the person for whom the path is being determined. According to some inventive embodiments, the determination of a path includes a preliminary finding of two or more paths that meet the foregoing inventive standard, and a final selection among them of the single path that best conforms (e.g., in terms of average regional clearance level characterizing the path) with the personal clearance level associated with the person for whom the path is being determined. 
     As typically embodied, the present invention is a web-based tool for providing walking directions for people traveling within the parameters of a facility that is subject to one or more restrictions. A prime example of a restricted access facility is a U.S. Navy ship, which usually has onboard many Navy military people (including officers and enlisted personnel) along with some people who are not Navy military. The present invention typically provides an interactive shipboard client-server computer network that includes a server and multiple clients. The server is a central computer having inventive software installed therein for processing direction requests by persons using client computers. A person makes a directions inquiry from a client computer by typing in his/her username and password, a starting onboard location and an ending onboard location. The clients can include workstation computers (e.g., for Navy personnel) and/or specially dedicated “direction-finder” computers that are strategically stationed at various locations onboard the ship. The client computer displays textual and/or graphic directions, originating from the server, that can be printed out by the client computer user. Various computer program products in accordance with the present invention can be made available (e.g., on compact disc) for installation, as would be suitable for creating and/or maintaining the present invention&#39;s network. Although the present invention is typically practiced so as to implement a computer network (e.g., internet or intranet), the present invention can also be practiced utilizing one or more computer program products (e.g., residing on one or more compact discs) in the absence of networking requirement or capability. For instance, inventive direction-giving cd-roms can be distributed to facility personnel in accordance with personal clearance level, wherein a different cd-rom edition (entitled, e.g., “VIP Edition,” “Manager Edition,” “Employee Edition”) is issued for each personal clearance level. 
     The present invention thus advantageously promotes the independence of persons who are unfamiliar with a facility. As long as the directions are clear and the unacclimated new person fully appreciates that certain areas and spaces are off-limits to him or her, there is a tremendous upside to encouraging the self-reliance of the unacclimated person. Moreover, practice of the present invention is not relegated to restricted access facilities, but is possible for any facility. Inventive practice can be especially propitious for a restricted access facility, since such a facility already has in place a logical basis for distinguishing between or among two or more categories of people, for instance due to security concerns. Inventive practice can nevertheless prove useful for a facility that is not a restricted access facility, for instance in furtherance of alleviating pedestrian traffic congestion inside a facility. The present invention can serve as an effective traffic engineering tool for regulating the flow of pedestrian traffic, regardless of whether the inventive clearance level designations are logical, arbitrary or some combination thereof. Furthermore, inventive principles are applicable not only to pedestrian travel but also to vehicular travel. For instance, there may be large numbers of pedestrians and vehicles (e.g., forklifts) that are concurrently moving about throughout a large and intricate factory complex. 
     The term “facility,” as used herein, broadly refers to any place or premises—for instance, all or part of a building, structure, edifice, factory, installation, complex, stadium, vehicle or vessel. The term “restricted access facility,” as used herein, broadly refers to any facility that contains one or more areas or spaces to which access is restricted. A space or area is “accessible” if it is physically capable of being reached or entered. “Restricted” access to a space or area suggests lack of permission to access such space or area with regard to at least one person or at least one group. Restricted acess usually entails permission of access with respect to some people and non-permission (e.g., denial) of access with respect to other people. Access to a space or area is “restricted,” for instance, if one or more groups of people are not authorized to reach or enter the space or area. The term “clearance,” as used herein, is a general term meaning permission to proceed. 
     Other objects, advantages and features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the present invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein like numbers indicate the same or similar components, and wherein: 
         FIG. 1  is a schematic of an interactive client-server network as typically embodied in accordance with the present invention. Although a single client is depicted in  FIG. 1  for illustrative purposes, it is to be understood that any number of such clients can be included in the inventive network, each client being connected to the server in the manner shown. 
         FIG. 2  is a diagrammatic representation of two equivalent sets of four clearance levels, viz., a set of four personal clearance levels and a set of four regional clearance levels. The two sets are shown juxtaposed in  FIG. 2 . As further illustrated in  FIG. 2 , each personal clearance level is characterized by permission of access to the regional clearance level of the same level number or smaller. Conversely, each regional clearance level is characterized by permission of access by the personal clearance level of the same level number or greater. 
         FIG. 3A  and  FIG. 3B  together constitute a flow diagram of an interactive method, as typically embodied in accordance with the present invention, for providing directions for an inquiring individual from one location to another within the parameters of a facility such as a restricted access facility. 
         FIG. 4 ,  FIG. 5  and  FIG. 6  are examples of web pages as they might appear to a user of a client computer that is part of a web-based (e.g., internet or intranet) client-server networked system in accordance with the present invention as typically embodied.  FIG. 4  portrays an introductory page on which the user can log in/on.  FIG. 5  portrays a directions request page on which the logged in/on user (logged in/on via  FIG. 4 ) indicates a starting location and an ending location.  FIG. 6  portrays a directions provision page (responsive to the directions request via  FIG. 5 ), which the logged in/on user can view and, optionally, print out. 
         FIG. 7  is a flow diagram illustrating how the “best available route” is selected in accordance with some embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIG. 1 , a typical computer-networked system in accordance with the present invention includes a server  1000  and multiple clients  100 . Server  1000  includes a processor  110  and a storage device  120 . Each client  100  includes a computer  10  (which includes a processor  11  and a storage device  12 ), an interface unit  20  (which includes a keyboard and a mouse), a display  30  and a printer  40 . Installed in each client  100 &#39;s storage  12  and in server  1000 &#39;s storage  120  are client&#39;s network software  13  and server&#39;s network software  130 , respectively, which together enable communication between each client  100  and server  1000  in the context of the inventive networked system. Also installed in server  1000 &#39;s storage  120  are a user identification (ID) database  140 , a facility-mapping database  150 , and routing application program  160 . The present invention&#39;s routing application software  160  includes provision for interactive communication (including logging in, requesting directions, and providing directions, all via a directions website) and directions determination (including processor access to user ID database  140  and facility-mapping database  150 ). 
     With reference to  FIG. 2 , a fundamental aspect of the present invention is the provision of two equivalent but converse clearance level hierarchies, viz., a personal clearance level hierarchy (represented in the lefthand column of  FIG. 2 ) and a regional clearance level hierarchy (represented in the righthand column of  FIG. 2 ). The personal clearance level hierarchy pertains to the authorized occupants of the facility, who are described in user ID database  140  in terms of username, password and personal clearance level. The regional clearance level hierarchy pertains to the layout and regions of the facility itself, which are described in facility-mapping database  150  in terms of region, region location, region dimensions and regional clearance level. The personal clearance level hierarchy and the regional clearance level hierarchy are characterized by converse access (e.g., entry) permissibility schemes. 
     To elaborate, as shown in  FIG. 2 , personal clearance level four (the highest personal clearance level) is followed by personal clearance level three (the second highest personal clearance level), which is followed by personal clearance level two (the third highest personal clearance level, which is followed by personal clearance level one (the lowest and fourth highest personal clearance level). In parallel fashion, regional clearance level four (the highest regional clearance level) is followed by regional clearance level three (the second highest regional clearance level), which is followed by regional clearance level two (the third highest regional clearance level, which is followed by regional clearance level one (the lowest and fourth highest regional clearance level). Some people are attributed with personal clearance level four, some people are attributed with personal clearance level three, some people are attributed with personal clearance level two, and some people are attributed with personal clearance level one. Similarly, some regions are attributed with regional clearance level four, some regions are attributed with regional clearance level three, some regions are attributed with regional clearance level two, and some regions are attributed with regional clearance level one. 
     A personal clearance level four person is permitted access to all regions at any of the four regional clearance levels, viz., any regional clearance level four region, any regional clearance level three region, any regional clearance level two region, and any regional clearance level one region. A personal clearance level three person is permitted access to all regions at three of the four regional clearance levels, viz., any regional clearance level three region, any regional clearance level two region, and any regional clearance level one region. A personal clearance level two person is permitted access to all regions at two of the four regional clearance levels, viz., any regional clearance level two region and any regional clearance level one region. A personal clearance level one person is permitted access to all regions at one of the four regional clearance levels, viz., any regional clearance level one region. 
     As compared with the permissions associated with the personal clearance levels, the permissions associated with the regional clearance levels operate in a reverse manner. A regional clearance level one region permits access to all persons at all four personal clearance levels, viz., any personal clearance level four region, any regional clearance level three region, any regional clearance level two region, and any regional clearance level one region. A regional clearance level two region permits access to all persons at three of the four personal clearance levels, viz., any personal clearance level four person, any personal clearance level three person, and any personal clearance level two person. A regional clearance level three region permits access to all persons at two of the four personal clearance levels, viz., any personal clearance level four person, and any personal clearance level three person. A regional clearance level four region permits access to all persons at one of the four personal clearance levels, viz., any personal clearance level four person. 
     According to typical inventive practice, user ID database  140  contains identifying information (e.g., full name, date of birth, place of birth, military rank, civilian government employment grade, contractor employment information, assignment or detail, and/or security clearance), along with the user name (username) and password, for every individual who is permitted to be present within the confines of the ship or other facility. The password can be changed (e.g., periodically) on the initiative of the user or at the instance of the server&#39;s network software  130 . For U.S. Navy ships, an efficient approach to compiling ship-mapping database  150  may include adoption of the U.S. Navy&#39;s uniform system of ship compartment designations, in accordance with which every ship is identifiably compartmentalized (regionalized). The existing designations for the compartments (regions)  151  onboard the ship can be incorporated into database  150 . 
     The U.S. Navy&#39;s compartment designation system assigns to every space (except certain minor spaces) a compartment designation consisting of three numerical symbols and a letter symbol that are separated by dashes. Each compartment designation is displayed (e.g., in photoluminescent paint) on a label plate referred to by Navy sailors as a “bulls-eye.” Each bulls-eye is attached to a door, bulkhead or hatch of the corresponding compartment  151 . According to the U.S. Navy&#39;s compartment designation system, a compartment designation consists of: (i) a deck number (e.g., main deck, second deck, third deck, etc.); (ii) a frame number, indicating the relationship of the compartment relative to the bow of the ship in a longitudinal direction; (iii) a port-versus-starboard number, indicating the relationship of the compartment relative to the centerline in a transverse direction (wherein even numbers pertain to port side compartments and odd numbers pertain to starboard side compartments); and, (iv) a letter (or double letter) indicating the use of the compartment (e.g., “A” for stowage spaces, “AA” for cargo holds, “C” for control centers such as CIC, “L” for living spaces, etc.). For instance, according to the compartment designation “04-79-1-C,” the number “04” indicates the fourth deck above the main deck (which is indicated by the number “1”), the number “79” indicates frame number  79 , the number “1” indicates the first compartment to starboard side, and the letter “C” indicates compartment use as a control center. A deck number of “3,” for example, indicates the third deck (i.e., two decks below the main deck, which is deck number “1”). A centerline relationship number of “2” indicates the first compartment to port side. See, e.g.,  Basic Military Requirements , NAVEDTRA 14325, United States Navy, Nonresident Training Course, Naval Education and Training Professional Development and Technology Center, (NETPDTC), Pensacola, Fla., February 2002, Chapter 8 (“Ship/Aircraft Characteristics”), pages 8-11 to 8-13; The Bluejackets&#39; Manual, 19 th  Edition, United States Naval Institute, Naval Institute Press, Annapolis, Md., 1973, Chapter 8 (“Ship Construction and Operation”), pages 144-147 ; Principles of Naval Engineering , NAVPERS 10788-B, Revised Edition, prepared by the Bureau of Naval Personnel, Superintendent of Documents, U.S. Government Printing Office, Washington, D.C., 1970, Chapter 2 (“Ship Design and Construction”), pages 26-29. 
     By way of illustration of inventive practice associated with a U.S. Navy ship, a personal clearance hierarchy might be established along the lines of the following. Personal clearance level four designees are U.S. Navy personnel of rank E5 or above, or other U.S. military personnel of rank equivalent to E5 or above. Personal clearance level three designees are U.S. Navy personnel of rank E4 or below, or other U.S. military personnel of rank equivalent to rank E4 or below. Personal clearance level two designees are U.S. government employees or representatives who do not require an escort, or contractor employees or representatives who do not require an escort. Personal clearance level one designees are civilians to whom personal clearance level two does not apply (e.g., non-U.S. Government civilians, non-contractor civilians) and who do not require an escort. Personal clearance level four designees are permitted access to regional clearance level four compartments  151 . Personal clearance level four designees and personal clearance level three designees are permitted access to regional clearance level three compartments  151 . Personal clearance level four designees, personal clearance level three designees, and personal clearance level two designees are permitted access to regional clearance level two compartments  151 . All authorized individuals (i.e., personal clearance level four designees, personal clearance level three designees, personal clearance level two designees, and personal clearance level one designees) are permitted access to regional clearance level one compartments  151 . The variations are endless for configuring the personal clearance and regional clearance classification schemes. Factors such as governmental, military or company security clearance (e.g., top secret security clearance, secret security clearance, confidential security clearance) can be incorporated into the personal and regional clearance regimes. 
     Still referring to  FIG. 1  and  FIG. 2 , reference is also made to  FIG. 3A ,  FIG. 3B ,  FIG. 4 ,  FIG. 5 ,  FIG. 6  and  FIG. 7 . As illustrated in  FIG. 3A , the user logs on (logs in) to the inventive website by entering (using interface  20 ) his/her username and password at the website&#39;s home (or main) page, such as depicted in  FIG. 4 . The user is properly logged on provided that the routing application program  160 , looking to user ID database  140 , accepts both the user&#39;s username and the user&#39;s password. Once logged on, the user requests directions by entering (using interface  20 ) a starting location and an ending location at the website&#39;s directions request page, such as depicted in  FIG. 5 . When both the starting location and the ending location are accepted by application program  160  as being contained in facility-mapping database  150 , application program  160  continues through its directions-determination logic as illustrated in  FIG. 3B . 
     As depicted in  FIG. 4  through  FIG. 6 , the user is a Navy officer requesting directions from the Enlisted Galley to the Combat Information Center (CIC). The directions shown in  FIG. 6  are in the form of written step-by-step instructions accompanied by two plan views, viz., of two adjacent ship decks. A bold path line traces the route from the starting location (compartment  1515 , which the Enlisted Galley includes) and the ending location (compartment  151 E, which the CIC includes). Compartments  151 S and  151 E, indicated in  FIG. 6 , are but two of numerous compartments  151  that are contained in ship-mapping database  150 . The insets containing compartments  151 S and  151 E, shown in  FIG. 6 , are for illustrative purposes and are not part of the display screen (viewable by the user) in  FIG. 6 . In database  150 , with the exceptions of certain minor spaces (e.g., some closets), all onboard space (or all accessible onboard space) is regionalized/compartmentalized; each region/compartment is assigned a minimum permissible clearance level, below which access is denied. 
     There are diverse types of graphic displays that are possible in inventive practice for communicating the directions to the user. Although plan views are provided to the user as depicted in  FIG. 6 , inventive practice admits of the possibility of one or more plan views, elevation views and/or perspective views, in any combination, and of any portion of (e.g., a single deck or a group of longitudinal frames) or the entirety of the ship. In addition, some inventive embodiments provide for a kind of “virtual reality tour” whereby the user views, on the display screen, a dynamic rendering of the pedestrian route from the starting location to the ending location. For instance, upon the completion and entering of the user&#39;s directions request such as shown in  FIG. 5 , the display screen splits and the user views a visual walk through the route from the starting location to the ending location; once the visual walk is completed the user may have the option of repeating the visual walk or may log off. If the user does nothing, the computer can wait a period of time and then reset itself for the next person. 
     The user is identified, from user ID database  140 , as having a particular personal clearance level. For instance, taking the example shown in  FIG. 2 , every user contained in user ID database  140  is designated as having either personal clearance level four, or personal clearance level three, or personal clearance level two, or personal clearance level one. In accordance with the personal clearance level of the user, application program  160  delimits the scope of possibilities of “available” routes—i.e., routes that are permitted to be taken by the user. An “available” route is a route that connects the starting and ending locations and that only touches regions having a regional clearance level that is equal to or less than the personal clearance level of the user. Application program  160  goes on to determine the “best” available route for the user, which is exhibited by application program  160  on the website&#39;s directions provision page, such as depicted in  FIG. 6 . A typical inventive reasoning process of narrowing down the routing possibilities to a single “best” available route is illustrated in  FIG. 7 . The user views the directions on display  30 , and/or prints out the directions using printer  40 . The user also has the option of requesting directions for a different pair of starting and ending locations. When the user has completed his/her session, he/she logs off (logs out) from the website. 
     The generally preferred inventive approach is to communicate to the inquiring person a single route, although it is possible in inventive practice to design an inventive application program that communicates two or more routes, thus allowing the inquiring person the option of choosing the route to be taken. Inventive practice typically determines what is referred to herein as the “best available route,” which is based on personal clearance and regional clearance information. In the expression “best available route,” the adjectives “best” and “available” pertain to different aspects of an inventively determined route. An “available” route is any route that can be taken in accordance with basic inventive principles insofar as being consistent with a given person&#39;s personal clearance level and the regional clearance level scheme of the facility. As for finding which available route is “best,” inventive practice can embody any of multifarious possible ways for reaching this decision. For instance, a server  100  can be inventively programmed to preliminarily determine all of the available routes, and to then finally determine which available route is the “best available route”; if there is only one available route, then the best available route has already been determined. 
       FIG. 7  represents but one example of this kind of multi-stage logic in accordance with the present invention. In Stage I, the inventive application program determines all of the available routes by applying the present invention&#39;s fundamental standard that no route shall encounter a regional clearance level that is higher than the personal clearance level of the person being directed. If more than one available route is found in stage I, the inventive application program proceeds to Stage II. In Stage II, the inventive application program applies a distance criterion, selecting, from among all of the available routes, a small number of (e.g., the two or three) available routes that are shortest in distance. An algorithmic cutoff can be applied to limit the number of available routes under consideration in terms of acceptable variation of distance. In Stage III, the program applies a “priority” criterion so as to choose a single route from among the two or three routes resulting from Stage II. According to this prioritization, the route selected is that which is most in comportment with the personal clearance level of the person being directed. 
     To illustrate by way of example the present invention&#39;s prioritized selection of a best available route, let us assume that the present invention attributes, to a company&#39;s large facility, four personal clearance levels and four matching regional clearance levels, viz., Levels,  4 ,  3 ,  2  and  1 , in order from highest to lowest. Level  4  is the highest (most permissive) personal clearance level, reserved for corporate officers and VIPs. Level  3  is the second highest (second most permissive) personal clearance level, reserved for managerial personnel. Level  2  is the third highest (third most permissive) personal clearance level, reserved for non-managerial personnel. Level  1  is the lowest (least permissive) personal clearance level, reserved for visitors and guests. A Level  3  person goes online, seeking directions from the cafeteria to the tennis court. Stage I-through-Stage II reasoning by the inventive application program yields two alternative available routes, viz., Route A and Route B, as follows. Route A: cafeteria, to Level  1  region, to Level  2  region, to Level  2  region, to Level  3  region, to Level  3  region, to tennis court. Route B: cafeteria, to Level  1  region, to Level  1  region, to Level  1  region, to Level  2  region, to Level  2  region, to Level  2  region, to tennis court. A Level  2  person goes online seeking directions from the same starting point (cafeteria) to the same ending point (tennis court). The only available route that is determined for the Level  2  person via the inventive application program&#39;s Stage I reasoning is the above-noted Route B. 
     Continuing with this example, by various forms of reasoning Route A may be considered to be more suitable than Route B for the Level  3  person. Typically, the present invention&#39;s goal in Stage III is to select the “best-fit” route as the best available route; that is, Stage II selects, from among the Stage II-determined candidates for the best available route, the one route that is the very best “fit” for the person being directed in terms of that person&#39;s personal clearance level. Depending upon the inventive embodiment, this best-fit route is variously arrived at. Some inventive embodiments incorporate in some capacity, into the best-fit reasoning process, the premise that higher personal clearance level individuals should be permitted “better” routes than lower personal clearance level individuals. Inventive practice can be geared in various ways toward favoring the higher personal clearance level individual over the lower personal clearance level individual. More generally, a typical inventive strategy is to find routes that are commensurate with the personal clearance levels of the users. Nevertheless, not every pair of starting and ending locations will have mutually exclusive routes for every personal clearance level; that is, for given starting and ending locations, the inventively determined routes may vary, but will not necessarily vary, for two or more individuals having different personal clearance levels. 
     One inventive approach is to adopt, as the best-fit route, the available route in which the “average” regional clearance level is closest to the personal clearance level of the person being directed. This “average” regional clearance level can be, for example, the arithmetic mean of the regional clearance levels corresponding to the regions encompassed by the route. According to this rationale, Route A is characterized by an average regional clearance level of 11/5=2.2, whereas Route B is characterized by an average regional clearance level of 9/6=1.5. Alternatively, either the median or the mode can be taken of the pertinent regional clearance levels. As another alternative, for each of the candidates for best available route, an “average” is taken of the regional clearance levels along the overall distance (length) described by the route, with different percentages of the overall route distance/length being associated with different regional clearance levels. 
     Regardless of how the “average” of the regional clearance levels is inventively defined, this “average” is taken of the route between, but not including, the starting location (cafeteria) and the ending location (tennis court). Inventive incorporation of the notion of “average” regional clearance level might inherently serve to promote better inventive route selections for higher personal clearance level individuals. In a qualitative sense, the best-fit route often comes down to that route whose predominant regional clearance level best matches the personal clearance level of the person being directed. By affording the capability of applying a prioritization model of these types to all individual direction requests, inventive practice may serve to attribute balance to, or alleviate congestion of, pedestrian traffic patterns. In the above example, it is consistent with such objective if the Level  3  person and the Level  2  person are advised to take different routes from the same starting location (cafeteria) to the same ending location (tennis court); that is, the Level  3  person is directed along Route A, whereas the Level  2  person is directed along Route B. 
     Installation of an inventive system onboard a ship can be accomplished in several phases. By way of example, during an initial phase an AutoCAD layout of the ship is obtained using a three-dimensional (3D) computer tool such as VIRTOOL (“Virtual Reality for Machine-Tool”), an interactive application under development by a European consortium. VIRTOOL uses 3D graphics and virtual reality. A layout for a class of ship (e.g., a U.S. Navy ship class such as CG, CVN, etc.) may already be available in AutoCAD format, and this may lend itself to incorporation into the VIRTOOL rendering. Upon completion of the ship layout in 3D, the ship is mapped out using regional designations for all accessible locations, such as the aforenoted compartmental designations commonly used for U.S. Navy ships. For instance, correspondence is made or adopted between the CIC (Combat Information Center) and the compartmental designation “03-0-45-0.” The personal and regional clearance level classification schemes are established, subject to the approval of the ship captain. In order that the ship maintain absolute control over who gains physical access to the ship and how deep the physical access is, a ship department is tasked with controlling user access to the inventive system; only the designated ship department grants the passwords and permissions. Once the inventive system is completely installed and tested onboard ship, the inventive system is ready for end use. The controlling department personnel are trained to operate and maintain the inventive system, including correcting any computer glitches that may arise. 
     The present invention, which is disclosed herein, is not to be limited by the embodiments described or illustrated herein, which are given by way of example and not of limitation. Other embodiments of the present invention will be apparent to those skilled in the art from a consideration of the instant disclosure or from practice of the present invention. Various omissions, modifications and changes to the principles disclosed herein may be made by one skilled in the art without departing from the true scope and spirit of the present invention, which is indicated by the following claims.