Abstract:
A method of constructing an elevated roadway, utilizing a crane having an articulated boom arm and a gripping mechanism, at the end of the arm for gripping a pylon, below a roadway cradle of the pylon, in order to temporarily transfer loads, generated by a tramway moving a precast bridge section along the crane arm and onto a pair of cradles, mounted upon the pylons. The construction method permits the crane to be positioned on an assembled portion of the elevated roadway, while constructing the remaining portion of the elevated roadway.

Description:
CROSS-REFERENCE TO RELATED DOCUMENTS 
     The present application is a divisional application of prior patent application Ser. No. 09/289,159 filed Apr. 9, 1999 now U.S. Pat. No. 6,169,954. 
    
    
     FIELD OF THE INVENTION 
     The present Invention is in the field of mass transit and pertains more particularly to methods and apparatus for enabling an intelligent public transit system using dual-mode vehicles. 
     BACKGROUND OF THE INVENTION 
     As urbanized areas in major industrialized nations have become more congested in population, roadways, turnpikes, expressways, freeways, and the like have become more and more congested, and new ways of moving people have become more important. A good example of such congestion is in Southern California, particularly the Los Angeles area. Urban sprawl continues for many miles around Los Angeles, requiring ever more investment in highway infrastructure, which the relatively recent devastating earthquake in that area proves is a vulnerable investment. 
     These developments over many years have also prompted development and implementation of various mass transit schemes designed primarily for commuters who live and work in the area. Bus systems, train systems, and other rail-type mass transport systems are generally available for commuters in the more industrialized and modern areas. 
     There are also many congested urban areas around the world that are not modernized with respect to transportation. Often too few roadways are available in these areas. The roadways that are available are often congested to the point of gridlock. Lacking rail systems, commuter-lane freeways and other such infrastructure enjoyed in more modern urban areas, these poorer areas are disadvantaged, at least from the aspect of efficient transportation infrastructure, such that they may not contribute and develop economically, as they would be enabled to do if there were adequate transportation. 
     It has been generally believed that introducing more conventional forms of mass transit such as rail systems, more buses, trolleys, etc. could alleviate congestion problems on roadways and the like. To this end billions of dollars are devoted to more-or-less conventional mass transit systems. However, it has been found that in modern areas people more often prefer independent modes of travel, such as by automobile, even when commuter lanes on freeways are available for private automobiles, it seems most commuters would rather go it alone than join a carpool or solicit others to form one. Moreover, rail systems and other common mass-transit modes are enormously expensive and must be generally supported through paying ridership by the public. When enough individuals cannot be solicited to patronize such a system, it may suffer from lack of maintenance, poor service, and in some instances, service may be discontinued altogether. The alternative of building more freeways to accommodate individual motorists is extremely expensive and takes up otherwise usable space. 
     In view of the above considerations, it is very desirable as public policy to provide an economically-feasible system of mass transit that also provides personal privacy and individual freedom to users of such a system. While there have been efforts to provide more personalization and individuality with respect to mass-transit modes, these systems are often prohibitively expensive, or do not provide enough individuality or personalization to attract large numbers of users, which, in the long run is self-defeating. Some of these prior art systems involve no more than providing improved communication between transit authorities and passengers, while others attempt to provide independent modes of travel on special roadways that are modified from existing roadways, or built new at extravagant costs. 
     One such prior art system is taught by U.S. Pat. No. 5,669,470, issued on Sep. 23, 1997 to Howard R. Ross, hereinafter referred to as Ross. Ross provides an electrically-powered vehicle with on-board batteries adapted to ride on a special designated roadway adapted to inductively distribute electrical energy to each vehicle. While this system may alleviate some traffic on normal roadways and provide for individually personalized transportation, either normal roadways must be modified, or new roadways must be constructed to facilitate such electrically powered vehicles. 
     Breaking up existing roadways is extremely expensive as is building new roadways. Moreover, with many roadways already widened to support special commuter lanes, it is doubtful that adding lanes for electric vehicles would be practical even if the expense could be met. 
     Another prior art system, U.S. Pat. No. 5,739,744 issued to Antonio Carlos Tambasco Olandesi, hereinafter referred to as Olandesi, simply provides computer capability to gas-powered buses in a transit capacity. Such capability affords drivers and passengers with a knowledge of scheduling information, current time status such as length of delays, scheduled arrivals, and so on. The onboard computer means communicates with terminals at stops along the route. However, passengers still must pack in as a group and do not have any individual control accept for boarding and disembarking, as with conventional bus systems. 
     Still other prior art systems provide individual vehicles adapted to ride on a rail-like above-ground structure. Almost invariably, such systems require rigid confinement of the vehicles to the rail-structure such that the vehicle is constrained to ride on a special rail or in a special groove. No dual mobility is afforded with these rail systems which is a common constraint seen with many prior art aboveground rail systems. 
     It is desirable in view of the above limitations associated with the state of the art to provide a transit system that provides a passenger with all of the privacy of driving a personal vehicle, while also enabling the passenger to enjoy a worry-free commute void of any requirement to navigate the vehicle. It is further desirable to provide such a system relatively inexpensively and with infrastructure that is modular in nature and may be quickly assembled or taken down without taxing precious land resource or significantly disturbing the environment. 
     One prior art system that provides a relative few of the desired characteristics described above is taught by U.S. Pat. No. 5,473,233 issued on Dec. 5, 1995 to Mark A. Stull and George F. Dippel, hereinafter referred to as Stull et al. Stull et al. teaches a mass transit system that uses a special roadway whereon a vehicle is driven via electromagnetic power provided by an electric utility and special electromagnetic elements or coils implanted at short intervals along the roadway. The implanted elements communicate with magnetic apparatus (large magnets) installed in each vehicle. The vehicles are urged forward by an electromagnetic current distributed at various modulations to control the speed of each vehicle. 
     Each vehicle in the Stull et al. system may operate in dual mode in the sense that when not on the special roadway whereon electromagnetic propulsion is the only option, it may be operated as an electric vehicle capable of self-propulsion on a typical surface roadway. Each vehicle is adapted to carry only a few passengers, a constraint necessary due to the mode of travel. 
     One problem with this system is that it relies on a special roadway that must be modified from an existing roadway, or created new. As described above, tearing up existing roadway to embed special surfaces and electromagnetic modules is prohibitively expensive. Such a dedicated roadway or guide-way also requires many entrance and exit ramps of sufficient length to accommodate acceleration to an optimum speed of travel, which may be up to 150 miles per hour according to Stull. Similarly, the amount of electric current needed to provide power for the embedded coils limits the scope of Stull&#39;s system requiring, that it be implemented for short distances only such as in urban locales. This constraint limits the number and type of commuters that may benefit to those local commuters living within the city. Moreover, in areas where heat during the summer may cause unusual demand on electricity, the system appears vulnerable. 
     Even though the infrastructure of Stull et al. is prohibitively expensive and complex, a desirable feature is exhibited with respect to the vehicles. That is that each vehicle is equipped with an on-board computer means for communicating with a “computerized global system”. Such communication capability includes diagnostic evaluations of vehicle integrity for traveling on the system, control of vehicle speed, and control of vehicle position as related to other vehicles traveling on the same guide-way. Unfortunately, the global system uses hardwired local control stations having a plurality of roadway modules that must be installed and operational for successful vehicle to system communication. Such wiring and distributed modules must be constantly maintained and tested which is an ongoing and considerable expense. 
     More importantly, vehicles traveling on the guide-way are not self-propelled. Rather, they are controlled as a group under a shared system of electromagnetic propulsion. This fact introduces an undesired complexity wherein the global system must communicate with each vehicle and the power source supplying the shared power. Based on each individual vehicle needs, the global system must regulate the electromagnetic system so as to supply the required power at the required location within a required time window such as when vehicles must be brought up to speed for entering the system. In fact, the electromagnetic system must be divided into two parts: one for the main guide-way, and one for the entrance and exit ramps. This kind of complexity is difficult to maintain even over short distances. Furthermore, the speed capability of Stull et al&#39;s system is disclosed as from 50 miles per hour to 150 miles per hour. While this capability may be impressive in a long, straight, commute, a short distance would never require such capability, and as Stull&#39;s vehicles are not constrained to the guide-way, an element of danger is exposed at higher speed levels. 
     As can be seen above, Stull et al, while able to provide some individual privacy for commuters by way of dual-mode vehicles, fails to provide a system that is economical and practical for more than short-range use. It is even dubious that a short-range system practicing under the concepts of Stull et al. could be implemented economically, especially in areas that are not particularly rich in resources. Much innovation is still needed to achieve the desired characteristics for a really successful mass transit system. 
     For a mass transit system to be economical in terms of infrastructure, it must be modular in nature, meaning that the roadway must be of such a construction that it may be installed in urban, suburban, and rural areas without adding to existing roadways or otherwise disturbing useful land areas extensively. For a mass transit system to be successful in terms of providing convenience and amenity to proposed commuters, it must be flexible in nature, conciliatory toward commuter preferences, and affordable for commuters. For a mass transit system to be successful in terms of social practicability, it must, along with the above, be aesthetically acceptable within the community and help to solve transportation problems existing within the community. 
     Another apparent difficulty with the mass transit systems described above as in and defining the state of the prior art, is that all are relatively mechanically complex. That is, they all require in some degree power distribution in the roadway, complicated mechanical switching, and the like. Complexity equals expense and unreliable operations. 
     Accordingly what is clearly needed is a mass transit system that is very simple, avoids mechanical complexity, can be personalized to commuters, and that may be implemented regionally and economically in terms of infrastructure. Such as system would allow people to commute en mass while retaining individual privacy as if driving their own vehicle from point of departure to point of arrival to a final destination. Such a system would also allow less developed areas to obtain badly needed infrastructure at a minimal investment, which would also attract other economic investment. 
     SUMMARY OF THE INVENTION 
     In a preferred embodiment of the present invention a transit system is provided, comprising an internally powered, wheeled, transport vehicle having both manual controls enabling a user to drive the vehicle on a surface street and an on-board computer (OBC) system enabling software control of at least vehicle steering and velocity; and a controlled roadway system having a roadway surface upon which the transport vehicle runs on its internal power on the same wheels as on surface streets. On surface streets off the controlled roadway the manual controls are active, and on the controlled roadway the software controls are active. In a preferred embodiment in selection of computer control is triggered by entrance to the controlled roadway system. 
     In a preferred embodiment the transit system further comprises plural transport vehicles having individual OBCs and a roadway Master computer system, and the Master computer system and OBCs are enabled to establish two-way communication. The Master computer system preferably controls speed of transport vehicles on the controlled roadway in a manner to prevent any two transport vehicles occupying the same physical space. In this and other embodiments the Master computer system maps the controlled roadway into fixed length virtual packets traveling at a constant speed, identifies the packets uniquely, identifies all compatible transport vehicles uniquely, and controls transport vehicles to occupy virtual packets. 
     In embodiments of the invention there are access stations at predetermined positions along the controlled roadway, the access stations connecting to the controlled roadway by entrance and exit ramps such that transport vehicles may accelerate and join the controlled roadway via entrance ramps, and may also exit the controlled roadway via exit ramps and decelerate. 
     In some embodiments there are side-by-side lanes in the controlled roadway system, for opposite directions of travel. Also in some embodiments there are further enclosures covering substantial portions of travel lanes of the controlled roadway, such that air within the enclosure is caused to move in the direction of transport vehicle travel, therefore reducing air friction impeding progress of vehicles moving on the roadway. In some of these embodiments there is at least one air pump mechanism for moving air within the enclosure in the direction of vehicle travel. 
     In one aspect of the invention the communication system is by a wireless network. The wireless network in some cases covers the entire controlled roadway system and extends in range to cover a substantial portion of the range of compatible transit vehicles on surface streets, such that the Master computer may communicate with transit vehicle OBCs both on and off the controlled roadway system. Also in some embodiments the Master computer system is Internet-connected, allowing users of compatible transit vehicles to access and interact with Master computer functions by Internet connection with an Internet appliance. These functions include at least reserving space in specific time slots for travel on the controlled roadway system. In some embodiments transit vehicles are electrical vehicles (EVs). 
     In another aspect of the invention a wheeled personal transport vehicle (PV) is provided, comprising an on-board power plant; manual controls comprising at least steering and speed controls enabling an operator to operate the vehicle on surface streets; an on-board computer (OBC) system enabled to operate at least the steering and speed controls by software; and an exclusive selection mechanism for selecting either manual or OBC control. 
     In some embodiments of the PV the OBC comprises a wireless communication link to an off-board Master computer system, and the Master computer system selects between OBC and manual control for the PV. In some of these embodiments the manual controls operate through the OBC by providing input to the OBC which in turn drives steering and speed control mechanisms. 
     In some preferred embodiments the PV further comprises proximity sensors sensing proximity of structures to either side of the direction of travel of the PV, the proximity sensors providing input to the OBC, which uses the input in conjunction with software to steer the PV between the structures to either side of the PV. There may also be proximity sensors facing in the direction of travel of the PV and providing input to the OBC used for adjusting speed of the PV to adjust proximity of the PV to a second PV moving in the same direction of travel. The software executing on the OBC may use input from the side-facing proximity sensors and OBC steering control to cause the PV to selectively follow a structure to one side or the other of the direction of travel of the PV. This function can be used for entrance and exit switching on a controlled roadway. 
     In preferred embodiments the PV comprises a user interface with the OBC such that an operator is enabled to interact with functions provided by the off-board computer system. Such functions may include at least logging and reserving travel time and space on a compatible controlled roadway system. 
     In preferred embodiments of the present invention dual-mode vehicles are provided to operate both on surface streets and a unique controlled roadway, and the system is provided at a fraction of the cost of mass-transit systems capable of handling even a portion of the traffic this unique system may handle. The system and subsystems of the invention in a variety of embodiments are taught in enabling detail below. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 is an elevation view of a section of elevated roadway with personal vehicles (PVs) commuting on a personalized transit system (PTS) according to an embodiment of the present invention. 
     FIG. 2A is a cross-section of the elevated roadway of FIG. 1 taken along the sectioning lines  2 — 2  of FIG.  1 . 
     FIG. 2B is a cross-section of the elevated roadway of FIG. 1 taken along the sectioning lines  2 — 2  of FIG. 1 in an alternative embodiment. 
     FIG. 3 is an overhead view of an embarking-disembarking station of a PTS system according to an embodiment of the present invention. 
     FIG. 4 is an elevation view of a PTS-compatible personal vehicle (PV) with an on-board computer (OBC) and other components according to an embodiment of the present invention. 
     FIG. 5 is a general block diagram illustrating a PTS computer control network according to an embodiment of the present invention. 
     FIG. 6 is a block diagram of OBC  73  of FIG. 4 illustrating various required and optional components. 
     FIG. 7 is an elevation view of a vehicle coupling system (VCS) according to an embodiment of the present invention. 
     FIG. 8 is an end view of PV  15  illustrating various installed sensors and connections comprising a proximity sensing system. 
     FIG. 9 FIG. 9 is a plan view of an exemplary section of controlled roadway illustrating PV exiting capability. 
     FIG. 10 is a plan view of an exemplary section of controlled roadway illustrating PV entrance capability. 
     FIG. 11 is an elevation view of a portion of a partially-completed roadway illustrating a construction crane used in an embodiment of the invention. 
     FIG. 12 is an elevation view of the crane and roadway of FIG. 11 illustrating the crane in an intermediary position of construction. 
     FIG. 13 is another elevation view of the crane and roadway of FIGS. 11 and 12 illustrating the crane in a further position in construction of a roadway. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     According to a preferred embodiment of the present invention, a personal transportation system (PTS) is provided and implemented in a fashion such that much personalization is afforded to individual commuters. Personalization is achieved by providing self-propelled dual-mode personal vehicles (PVs) in which commuters may travel either on or off a unique controlled roadway system. Other facilitating systems and components thereof are provided as part of a unique overall personal transportation system (PTS). These include at least a modular infrastructure system that may be built up or taken down quickly and economically. Also, a Master computer system is provided for overall system management, diagnosing problems, and controlling aspects and performance of compatible vehicles. The Master computer system communicates with local stations of the controlled roadway and also with onboard computers in vehicles. In various implementations and embodiments of the system particular functions are assigned to different parts of the computer system. In a preferred embodiment the overall system is managed as a real-time continuing system wherein moving virtual positions, herein termed vehicle packets, for PVs in the system are constantly tracked, and recorded as occupied or available packets. 
     In various embodiments each PV is provided with an individual proximity sensing system which communicate both with an on-board computer (OBC) for the PV and in some instances with the Master computing system as well. The proximity sensor system in each PV is adapted to cooperate with the overall computer system to recognize PV positioning relative to other PVs and position on the controlled roadway, such as position integrity relative PV packets as introduced above, which are described in more detail below. 
     The proximity system in each PV reports to the OBC, which in turn reports to the Master computing system either directly or through local computerized stations. According to system parameters, the OBC systems control and adjust vehicle speed and steering while the PV is traveling on the controlled roadway. Proximity sensing between PVs moving on the controlled roadway provides a virtual coupling system, whereby PVs may behave as though coupled and moving in tandem. Additionally, in an alternative embodiment, a physical vehicle coupling system is provided and adapted to allow actual physical coupling or uncoupling of vehicles during operation on the controlled roadway. 
     Infrastructure 
     FIG. 1 is an elevation view of a section  13  of a controlled roadway in an embodiment of the invention with personal vehicles (PVs)  15  traveling on a personalized transit system (PTS)  11  according to an embodiment of the present invention. PTS  11  utilizes an infrastructure composed in many embodiments at least primarily of elevated roadway, of which one section is seen in this view. In many embodiments at least some portions of the controlled roadway may be at surface level or below as well. Some portions of controlled roadway  13  are shown in broken section to show otherwise hidden components. 
     Roadway section  13  is supported by two substantially upright pillars  21  in this example, spaced apart a suitable distance over the length of controlled roadway to support individual sections, such as section  13 . In this example, pillars  21  are conical, being circular in cross-section and tapered in shape from a base to a top end. In a preferred embodiment pillars  21  are manufactured from steel in a prefab fashion of standard lengths. In one embodiment, pillars  21  may be manufactured from steel and may take various shapes such as a tapered ribbed or finned pre-formed structures. In another embodiment, pillars  21  may be reinforced tubular structures having a welded outer skin of steel forming the tube portion of the structure. Suitable extension members (not shown) are also provided for attaining various lengths as may be required for implementation over uneven terrain. Such extension portions may be cut on-site if required to attain specific lengths as is known in the art of construction. It will be apparent to the skilled artisan that such support pillars may take many diverse forms. 
     Each pillar  21  in this embodiment has a steel pillar-support base  25  welded or otherwise rigidly affixed thereto. Support base  25  acts to stabilize pillar  21  such that it may be aligned and mounted by a method such as bolting to a concrete support pad  27 . Support pad  27  is typically made level and anchored into the earth by known methods of earth-anchoring structures. Such support pillars provide a modular support for elevated sections of PTS  11 , such that controlled roadway may be constructed over various surface terrains in virtually any surrounding environment. This type of elevated architecture may be implemented in urban, suburban, and rural areas without altering land and land use other than in the immediate vicinity of pads  27 . In many places pre-existing right-of-way may be used, such as railroad access, existing roads having easements, canals, fireroads, and the like. 
     Roadway section  13  in this embodiment comprises a roadway support tube  19 , a plurality of I-beam support members  31 , and a roadway surface  29 . Support tube  19  provides the base support for roadway  29 . Tube  19  is centrally located beneath and parallel to road surfaces  29 , which may indeed be multiple roadways. Tube  19  is preferably made of durable steel and is approximately 48 inches in diameter in this example, although many other sizes might be used. Support tube  19  has a wall thickness suitable for support and welding purposes. Tube  19  is structurally supported by a plurality of cross members  23  suitably spaced along roadway section  13 . Cross members  23  are of steel and are welded or otherwise rigidly affixed to tube  19  and in appropriate junctions, pillars  21 . Cross-members  23  act as a ribbing support, lending strength to roadway section  13  as well as providing support platforms from which other structure such as longitudinal walkways, side railings, and so on may be attatched. Such additional structures are not included in this view for the purpose of clarity as described above. 
     Roadway surfaces  29  are supported in an elevated position above support tube  19  by I-beams  31 . Each roadway surface  29  is, in a preferred embodiment, is at least partially a steel grating having openings therein for allowing snow and rain, and other debris, to fall through. I-beams  31  are welded or otherwise affixed on lower edges to tube  19  and on upper edges to roadway surface  29 . In a preferred embodiment, all of the major infrastructure components of roadway section  13  are manufactured from durable steel much like material used in the construction of steel bridges and railway structures. This construction provides maximum strength and is relatively lightweight. 
     In a modular architecture such as the one provided herein, pillars  21  may be lowered into position by, for example, a helicopter after crews have completed construction of concrete pads  27 . Sections of roadway  13  may be laid out along and between pillars  21  from already-constructed sections with the use of a wheeled and hydraulically operated support vehicle which will be described in enabling detail in a later section of this specification. By use of modular architecture and unique construction techniques taught herein, a dedicated route for PTS  11  may be constructed relatively swiftly and without significant disruption to the surrounding environment whether in an urban, suburban or rural area. 
     It should be apparent to one with skill in the art that there are many methods and a variety of known equipment that may be utilized to construct roadway section  13  of PTS  11  without departing from the spirit and scope of the present invention. For example, in areas where abundant access roads are available and suitable for transporting heavy equipment, pillars  21  may be erected by more conventional methods. Helicopter placement would typically be used in areas where access roads are unavailable and terrain is generally adverse to more conventional construction techniques 
     PVs  15  are provided in embodiments of the invention as dual-mode vehicles that are, in a preferred embodiment, self-powered and equipped with suitable human interface and controls such that they may be operated manually on conventional streets and highways. In many embodiments the PVs are electrical vehicles (EVs) operating on rechargeable battery packs. In some embodiments the PVs may be hybrid vehicles having both internal combustion power plants and electrical power plants. 
     When traveling on PTS  11 , over controlled roadway as shown, the vehicles are controlled individually by the system such that manual operation is not required. Rather, the vehicles are centrally controlled by the previously-introduced Master computer system (not shown in this drawing), or by subordinate computer stations in conjunction with the previously-described OBC systems. In this way, commuters may relax and enjoy a worry-free commute while on PTS  11 . Manual operation of PVs  15  is resumed after commuters disembark from PTS  11 , to enable the commuters to continue on to their ultimate destinations over surface streets and roads. 
     In some embodiments lane separation barriers  33  (partially shown) are provided to act as dividing and enclosing barriers between PVs traveling on dual lanes and between PVs and the outer peripheral edges of roadway section  13 . If PTS  11  has two PV lanes, for example such as one in each direction, then three barriers  33  might be used. One may be used as a center divider, and two as outer barriers for roadway section  13 . Outer barriers  33  also provide protection against wind and wind-blown debris. Barriers  33  are preferably constructed from suitable steel, but may also be constructed from other materials such as aluminum, or even from transparent material to allow a view of the countryside for commuters. 
     A PV  17  is illustrated in FIG. 1 to provide an example of a multi-passenger vehicle that may, in alternative embodiments, be used instead of or in addition to smaller personal PVs  15 . PV  17  is also self-powered such that operating on conventional surface roadways is possible as described above with PVs  15 . Similarly, control of PVs  17  is transferred to a central computing means once entering the controlled roadway. 
     FIG. 2A is a cross-section of roadway section  13  of FIG. 1 taken along section line  2 — 2  of FIG. 1, illustrating cross-member  23  and other components in additional detail. The architecture of roadway section  13  as seen in this view is of an inverted triangular shape with a relatively low profile and less mass than a traditional rectangular structure. This novel design aids in the overall strength of the infrastructure, especially providing resistance against high winds. 
     Cross-member  23  has, in this example has a number of through-openings, such as openings  47  and  45  for the purpose making the structure lighter in weight. In alternative embodiments more of fewer such holes may be used, or none at all. Cross-member  23  encompasses and is attached to primary longitudinal tubing  19  which supports all of the elements of the roadway section. Lateral girders  31  rest across tubing  19  as well, at spaced intervals along the roadway, not necessarily just at the position of the cross-members. Surface  29  of expanded metal provide a grid of openings as described above, such that water, snow and debris may fall through rather than building up on the roadway. Raised tracks  46  are provided, spaced apart the width of tires on the PVs, to engage the PV tires on the roadway. 
     In this example, there are two lanes shown for transportation with PV&#39;s  15 . The PVs are shown with little detail, but it may be assumed the two-lanes are for travel in opposite direction. In addition to optional barriers  33  (one center barrier, and two outer barriers), a rigid center divider  34  is provided in this dual-lane example. Divider  34  is adapted as a protective barrier between the two illustrated travel lanes, and also, in this embodiment as a guide to front wheels of PVs  15 , to guide the PVs on the controlled roadway. Retainer walls  43  are provided and adapted as protective barriers between lanes and provided outer pedestrian-walkways  39 . Such rigid barriers are constructed from a suitable material such as steel that is strong enough to repel debris in the event of an accident. In addition to center guide barrier  34 , outer guide barriers  36  are provided to additionally contain and guide PVs in operation. 
     In this embodiment guide barriers  34  and  36  have sloping faces toward the PV tracks, the sloping faces extending essentially to the outer edge of each raised track  46 . In this manner, a PV traveling along tracks  46  will have its front wheels guided by the guide barriers in addition to other guide apparatus and methods described below. 
     Pedestrian walkways  39  are shown in FIG. 2, but are not strictly required. Such walkways may be provided in some embodiments and not in others. Such structures may provide emergency access and for maintenance personnel to access certain areas of infrastructure. In the case of walkway structures such as walkways  39 , suitable step-down structures such as step-down  41  may be provided for access to the interior portion of roadway  13 . 
     In some embodiments emergency telephones may be provided at suitable intervals along walkways  39  for reporting any problems with the system such as debris damage, medical requirements, security problems, and so on. Such phone systems are expected to be used by maintenance personnel, rather than for any use by persons traveling in vehicles on the roadway. 
     In addition to walkways  39 , emergency stop lanes (not shown) may be provided for PV&#39;s  15  along any length of roadway  13  in case of a detected performance problem or passenger-communicated emergency. In the case of vehicle stop lanes, certain sections of PTS  11  would, of course, be wide enough to support such additional infrastructure including additional support pillars and so on. 
     In some embodiments of the present invention tube  19  may have additional uses. One such use is as a communication wave-guide, for communication between different subsystems. Also, access openings may be provided in tube structure  19  to enable a special maintenance vehicle to travel inside the tube to a problem location where suitable personnel access is similarly provided to roadway  13 . The openings may be provided in suitable surface locations of tube  19  that provide for simple access to a target roadway section such as section  13 . In this case, tube  19  may have a larger diameter enabling enough room for such a vehicle and personnel for travel. An enclosed stair-type or ladder style structure may be provided at each opening for insuring safety of personnel accessing a roadway section such as section  13 . In still other embodiments tube  19  may be used for gas or liquid transport, and the like. Many such uses are possible. 
     In a preferred embodiment, the controlled roadway has raised tracks  46  adapted to provided a smooth surface for PV tires. In this case, there are two such raised tracks  46  placed longitudinally in each travel lane with one surface  46  proximate to and adapted to make contact with the left-side wheel arrangement, and the remaining surface  46  proximate to and adapted to make contact with the right-side wheel arrangement of each PV  15 . As described above, the outer edges of the span of the raised tracks are proximate the angles surfaces of guide barriers  34  and  36  to form, in this embodiment at least, a physically-guided system for moving PVs. 
     In this particular example, there are two sets of proximity sensors  35   a  (left-set) and  35   b  (right set) mounted on each PV. Sensors  35   a  and  35   b , depending on type, may sense walls of barriers  34  and  36 , or may communicate with a plurality of cooperating proximity modules such as modules  37   a  and  37   b . Modules such as modules  37   a  and  37   b , where used, are located at the same height level as sensors  35   a  and  35   b  in a spaced-apart collinear arrangement along the length of barriers  34  and  36 . The technology for proximity sensing may be radar, photoelectric, or other known methods, and cooperating modules may or may not be required, depending on the type of proximity sensors used. Information gathered by proximity sensors such as sensors  35   a  and  35   b  is utilized by PV on-board computers (OBCs not shown here) to guide automatic steering of PVs in addition to, or instead of the physical guiding afforded by barriers  34  and  36 . A multi-passenger PV such as PV  17  of FIG. 1, if used, may have more than two sets of proximity sensors mounted to each side because of the significantly longer length. The operation of such sensors and cooperation with the OBCs and other elements of PVs is dealt with in further detail in sections of this specification below. 
     In one preferred embodiment, front and rear proximity sensors and modules (not shown) are provided on the front and rear of each PV. Continuous data defining the distance between successive vehicles as gathered by such sensors is utilized by OBC&#39;s of each PV to control speed of each PV according to an ideal and constant separation value, and to cooperate with the Master computer system in placing PVs, and maintaining their presence, in virtual PV packets as introduced above. This system will also be described in further detail below. 
     In another embodiment, front and rear sensors are not required because side proximity sensors may be utilized to provide PV speed and position relative to standard positions on the controlled roadway. Such information taken this way may be relayed to a local or Master computer station, analyzed, and then sent back to individual OBC&#39;s in respective vehicles as commands for speed adjustment requirements. In some embodiments PV-to-PV 
     It will be apparent to one with skill in the art that actual structural features may be added or subtracted from roadway section  13  without departing from the spirit and scope of the present invention such as in the addition of stop lanes, access passageways, and so on. The inverted triangular design of cross-members  23  and their close proximate spacing provide ample means for adding additional structural features to the roadway. 
     In a preferred embodiment of the present invention, stations are provided at strategic locations along any given PTS route whether urban, suburban or rural. Each station is adapted to allow commuters to safely embark and disembark from PTS  11 . An example of one such station is provided below. 
     Embarking and Disembarking Stations 
     FIG. 3 is an exemplary overhead view of an embarking-disembarking station  49  of PTS  11  according to an embodiment of the present invention. Station  49  is exemplary of an embarking/disembarking point for commuters entering and exiting PTS  11 . Station  49  may vary in architecture and functions as required to facilitate particular areas along PTS  11 . For example, if station  49  is in an urban area, architecture and facilities will serve those needs. If station  49  is in a rural area, then architecture and facilities may be significantly less complex than shown in FIG. 3 in accordance to rural needs. It can be assumed that in this particular example, station  49  is a full-service station. Station  49  has a plurality of lanes dedicated to connecting commuters to various facilities, junctions to normal roadways, points of entrance, points of departure, and so on. 
     The controlled roadway, now defined as a connected plurality of previously-described elevated roadway sections  13 , comprises two main traveling lanes  54  and  56  in this embodiment, one for each direction of travel on the PTS. Commuter travel in this example is bi-directional. In other instances, there may be fewer or more lanes as required to service an area or region. Lane  54  has an exit loop  51   a  located at the site of station  49  which is adapted to allow commuters to exit PTS  11  and to continue on surface roads and streets to nearby destination locations and so on. The intersection of lane  54  with exit lane  51   a  is actually off the figure to the right. Lane  54  also has an entrance loop  53   b  located at station  49  which is adapted to allow commuters to enter PTS  11  for remote destination points (typically other stations located near their ultimate destinations). Lane  56  has an exit loop  51   b  and an entrance loop  53   a , which are adapted as described above with loops  51   a  and  53   b.    
     Commuters wishing to enter PTS  11  may do so by first entering station  49  at a convenient staging location such as at entrance  57 . Curved entrance arrows proximate to staging location  57  illustrate direction of travel into station  49 . At this point each commuter is manually operating a PV such as PV  15  of FIG.  1 . In some embodiments a PV diagnostic facility  55  is provided as an enclosed structure with through-lanes having bays adapted to perform various vehicle diagnostic routines and verification routines associated with commuter authorization to travel on PTS  11 . In this example there are 5 lanes with each lane having one associated bay typically located inside the structure. Each bay is equipped with identical diagnostic and service facilities. Commuters simply drive their PVs into a lane and through an appropriate bay inside the enclosure, and a wireless communication connection s established between the appropriate bay and each PV OBC. 
     Diagnostic functions performed by a bay  55  may include but are not limited to checking PV batteries for integrity, checking tire pressure and wheel alignment, checking status and integrity of proximity sensors, testing OBC steering and speed control capabilities, testing OBC communication capabilities, and so on. Typically all of these functions and checked and monitored by each OBC for a PV, whether the PV is in a station or not. It is only really necessary that the OBC communicate the latest monitored information to the stations computer system, which is in constant communication with the Master computer system for the PTS. 
     By checking each vehicle a its comes into a station for access to the PTS, it is assured that no unstable vehicles are allowed to enter PTS  11 . Verification of driver fitness and authorization may be done as well and may include, but is not limited to, verifying driver identification, verifying destination, securing payment for travel, checking driver alertness or medical status, security check for contraband, and so on. 
     In an alternative preferred embodiment of the present invention it is not necessary to encumber stations with the vehicle checks. Alternatively PVs and their OBCs are in constant wireless communication with the PTS Master computer system, and all PVs that might be eligible for travel on the PTS. In this system each PV is known to the Master computer system by a unique identifier, and each PV is constantly tracked, so all necessary information is known tot he Master system. In such a system, as is further described below, commuters may also communicate travel plans to the PTS system ahead of time, make payments and the like, and the Master system considers all PVs at all times, whether the PVS are in the PTS system or not. There are many advantages to this comprehensive system. 
     In a preferred embodiment of the present invention PVs travel on the controlled roadway under power only from their on-board potential energy sources, without power derived from the roadway. This provides for the least complicated architecture for the roadway itself. In this embodiment PVs are monitored and checked at entrance or at some near time prior to entrance for the energy state of the on-board potential energy source, such as a battery for an EV, against user-provided destination information. Adequate power capability with a safety margin is required for authorization to enter. 
     Medical checks may be made for commuters as well, such as intoxication tests, blood pressure or heart condition checks, history of phobias, and so on. For example, a driver with a phobia of bridges or heights may be advised not to travel on PTS  11 . A person found to be inebriated might be banned from travel on PTS  11 . High-risk individuals for heart attack or stroke may be advised before traveling and so on. Security checks may include checking for pets, explosives, weapons, or other common contraband. In a preferred embodiment, records are kept on the Master computer for any and all data important to function and safety for the PTS. 
     In station  49 , after being cleared for entrance, commuters are directed to one of a plurality of staging lanes  59   a-e . Staging lanes  59   a-e  are adapted to accept individual PVs destined for a same station or general destination location. In this way, a group of PVs comprising multiple PVs destined for a same location may be caused to travel in close proximity to one another such that they may exit together at a next common or destination station. This is preferred as a means for maximizing energy efficiency for travel on PTS  11 . A traveling group of PVs may be construed simply as more than one PV. The number of PVs traveling in any one group will vary according to congestive status of PTS  11  as a whole. For example, at odd hours not associated with regular commuting times, single PVs may be allowed to enter PTS  11  and travel without being associated with a group. 
     Upon entrance to the station, after maintenance and other checks, manual control of PVs is passed over to computer control from PTS  11 . Now individual OBC&#39;s associated with each PV are in constant communication with a local computer control station  70  that interfaces with a Master PTS computer system. According to information transmitted from local computer station  70  and destination parameters associated with each packet of PVs, individual groups of PVs are caused to embark to their destinations in unison maintaining a constant speed and spacing between each PV in the line. For example, local computer station  70  knows the positioning and time of arrival of any through-groups of PVs traveling on lanes  56  or  54 . A command for one of lines  59   a-e  arrives at such timing when it is known that the line may enter it&#39;s designated lane safely. 
     As a group from lanes  59   a-e  is released for entrance, it travels according to the directional arrow shown on lane  60  through a turnstile  65 . Turnstile  65  is adapted to direct a group of PVs to an appropriate entrance lane for either lane  56  or  54  as illustrated by directional arrows. For example, if a group is designated for entrance to lane  56 , then it enters lane  56  by way of entrance loop  53   a  and merges in with passing traffic at the appropriate and constant speed of travel on PTS  11 . Similarly, if a group is designated to travel on lane  54 , then turnstile  65  is switched to allow entrance to lane  54  by way of entrance loop  53   b.    
     In one embodiment, one of lanes  59   a-e  is designated to accept PVs having problems or having unauthorized PVs or unfit drivers. When such a line reaches turnstile  65 , it is directed or switched to an internal access loop  61  that is adapted to direct such vehicles into a maintenance facility  63  wherein problem resolution services may be performed. If successful problem resolution is reached, an approved PV may exit facility  63  on loop  61  and re-enter turnstile  65  where it may be integrated into an appropriate next group of PVs headed for a same destination. 
     If for some reason a problem cannot be resolved, an additional return lane (not shown) may be provided and adapted to return such PVs back to entrance location  57  where they may undergo additional diagnostics at station  55 , or perhaps, be swapped with an approved PV from a fleet of such vehicles that may be kept at station  49 . If a PV cannot be controlled by PTS  11  because of an OBC failure, then it may not be allowed to enter any of lanes  59   a-e . In this case, it may be redirected from station  55  to a parking area or to building  63  via alternate lanes (not shown). In a simple alternative, PVs failing one or more entrance requirement receive an electronic report card detailing the reason for rejection, and a recommendation for correction for future attempts at use of a PTS, and are then switched off the system and back onto the surface streets. There are many variable possibilities. 
     PVs traveling on PTS  11  need not enter station  49  when exiting lanes  54  and  56 . A suitable exit lane  71  is provided for all exiting PVs. For example, a line of PVs exiting from lane  54  will use exit loop  51   a  and access exit lane  71  at a suitable merge location. PVs exiting lane  56  use exit loop  51   b  and merge onto lane  71  at the same merge location. As PVs decelerate and merge onto lane  71 , they are directed to one of lanes  72   a-e  according to known ultimate destination locations obtained when they entered PTS  11  from another station. Lanes  71   a-e  represent passageways to local streets or roadways or freeway access roads leading to appropriate ultimate destinations. While PVs are in lanes  71   a-e , manual operation for each PV is restored to the driver allowing the driver to assume control and to continue on to a final destination. 
     In one embodiment, a suitable parking structure represented by dotted area  69  may be provided with entrance and exit lanes for commuters who work within walking distance of station  49 . Parking structure  69  may be as simple as an open parking lot, or as complex as a multi-story-parking garage. In the latter case, structure  69  may include facilities at each parking stall for re-charging PV batteries, in the case of EVs or hybrid vehicles for a return trip, or refueling for internal-combustion-powered PVs, and other apparatus such as overhead storage monorails for very efficient storage. In this way, commuters may return to a fully ready PV ready for a return commute, and PVs may be readily found as needed. 
     It will be apparent to one with skill in the art that a variety of lanes, facilities and other support architecture may be utilized in a station such as station  49  without departing from the spirit and scope of the present invention. For example, additional diagnostic and maintenance facilities may be provided for multi-passenger PVs such as PV  17  of FIG.  1 . Also, though not shown in FIG. 3, curved acceleration and deceleration ramps may be of fishook design, such that centripetal force effects are maintained at a constant value as vehicles are caused to accelerate and decelerate. 
     In one embodiment, PVs such as PV  17  may be intermingled with PVs such as PV  15  for traveling in lines with perhaps the multi-passenger PV being the lead vehicle. In still another embodiment, PVs such as PV  15  of FIG. 1 are kept at station  49 , and may be used by passengers who first park their gas powered vehicles in a designated area at a station such as station  49 , and so on. In a preferred embodiment, however, PVs such as PV  15  of FIG. 1 are dual-mode vehicles either owned or leased by individual commuters. The purchase or lease of such vehicles may insure unlimited ridership on PTS  11  while infrequent commuters must use multi-passenger vehicles such as PV  17  of FIG.  1 . 
     FIG. 4 is an elevation view of a PV  15  of FIG. 1, implemented as an EV with an on board computer (OBC)  73  and other components according to an embodiment of the present invention. PV  15  is, as previously described, a dual-mode vehicle, meaning that it may travel in a self-propelled mode on surface streets under manual control by a driver, and on a controlled roadway of PTS  11  (FIG.  1 ), under control of its OBC and the computer system of the PTS. 
     PV  15  in this embodiment has an aerodynamically profiled body that is constructed from lightweight materials such as fiberglass and durable polymers. The aerodynamic profile of PV  15  as illustrated here is not to be construed as a limitation, as many differing designs may be used without departing from the spirit and scope of the present invention, such as those of standard compact vehicles, or new designs. The inventor intends to exemplify the profile of PV  15  as just one possible aerodynamic profile that may be compatible with PTS  11 . 
     Frame components may be manufactured of durable metal such as steel. Other suitable materials known in the art may be used for the construction of PV  15  as long as they are durable and lightweight. PV  15  rides on wheels  75 , which are, in preferred embodiments, rubberized tires mounted on suitable wheel rims as is known with standard automobiles. 
     Access doors  77  in this embodiment open in an upward manner similar to known gull-wing doors on some standard automobiles. A hinge area  79  is provided and adapted to facilitate gull-wing style doors  77 . Doors  77  are used as a matter of convenience only. Sliding or conventional doors may be used instead. In barrier lanes where room is limited on either side of PV  15 , gull wing or sliding doors may prove more practical. 
     A plurality of rechargeable batteries  87  (labeled BAT) make up the potential power source of PV  15  as an EV. All suitable battery types and sizes as known in the art may be considered for use. Batteries  87  are mounted inside PV  15  in a convenient and unobtrusive space such as under the floorboards, or in a provided compartment adapted for the purpose, as is known in existing EV designs. Batteries power one or more electric motors (not shown) used to drive axles to power wheels of PV  15 . Batteries  87  also provide power for illumination systems such as head and taillights dash lights, turn signals and interior lights as well as communication and entertainment systems such as a CD stereo or audio system, and additionally OBC  73 . 
     OBC  73  provides control over all on-board systems including but not limited to, proximity sensors such as sensors  35   a  and  35   b  of FIG. 2, speed control systems, steering control systems, and other components required to operate and guide PV  15 . OBC  73  provides a number of functions, including a means for PV  15  to be operated by a Master computer system as communicated thereto either directly, or by a collaborating local computer station such as station  70  of FIG.  3 . 
     PV  15  in this embodiment is typically designed to carry two individuals, a driver and a passenger. However, in some embodiments PV  15  may carry only one or perhaps up to four or more persons. A cargo area  85  is provided in this example for stowing briefcases, jackets, and other personal items that are typically carried by commuters. Bucket seats such as seat  89  are provided to be able to recline for driver and passenger relaxation during a commute on PTS  11 . In alternative embodiments, bench seats may be provided. 
     In still another embodiment, a cargo area such as area  85  may be enlarged and the number of passengers restricted to one driver such as might be the case of a courier or delivery situation. It is also conceivable that while PV  15  is active on PTS  11  only cargo will be on board as a driver is not required to operate PV  15  when control is by computer system. There are many such possibilities. 
     As previously described, dual proximity sensors ( 35   b  illustrated here) communicate with lane barriers or embedded modules such as center divider  34 , guide barriers  36  and side barriers  43  (see FIG.  2 ). Suitable control lines link sensors and other computer-controlled system components (not shown) to OBC  73 . 
     In some embodiments a physical coupling system is provided and adapted to allow PVs such as PV  15  to be coupled and de-coupled while traveling on PTS  11  or at any other time. The coupling apparatus consists of a mechanized engaging member  83   a  illustrated as retracted within the front portion of PV  15  behind a front bumper  85   a . A hydraulic system  81  in this embodiment is provided and adapted to enable the extension of member  83   a . In other embodiments, other means of mechanization may be provided instead of hydraulic actuation. 
     At the rear portion of PV  15 , a coupling receptacle  83   b  is provided and adapted to accept an extended engagement member such as member  83   a . In this way, physical coupling can be achieved with multiple PVs in a line. A coupling system such as the one described above may be achieved in a variety of ways with varied mechanization schemes. A coupling system as described above is useful in a number of situations. Coupling with and towing a disabled PV, linking lines of PVs in case of a problem with the roadway. As previously described above, PVs such as PV  15  of FIG. 4 are controlled by a PTS computer system while traveling on PTS  11 . 
     FIG. 5 is a block diagram illustrating a PTS computer-control system according to an embodiment of the present invention. The PTS control system comprises a Master computer system station  95 , and a plurality of locally distributed computerized stations  87 ,  89 ,  91  and  93 . In a preferred embodiment, the overall system uses a wireless digital mode of communication suitable for transmitting data using a high bandwidth. The wireless network is illustrated by network cloud  97 . Computer stations  89  are, in many instances, located at access stations of PTS, but this is not a requirement or limitation in the invention. 
     Master computer station  95  may comprise a plurality of powerful connected computers or a single larger and more powerful computer capable of sending and receiving data between local stations  87 - 93  simultaneously, and of executing a tracking and operating system for PTS  11 . Master station  95  keeps track of all activity occurring on PTS  11 , and in some embodiments also keeps track of PVs off the PTS that are eligible to use PTS  11 . Accounts are maintained as well for commuters subscribed to and authorized to use PTS  11 , and the commuter&#39;s association with eligible PVs. 
     Current status for each local area or portion of PTS  11  is tracked and reported to Master station  95  by local computer stations  87 - 93  also referred to as slave stations. Slave stations  87 - 93  are analogous to computer station  70  of FIG.  3 . It may be assumed that there is an embarking/disembarking station such as station  49  of FIG. 3 associated with each slave computer station, although this is not a requirement. 
     Each slave station  87 - 93  in this embodiment has an area of control associated with its immediate vicinity along PTS  11 . Overlapping dotted ellipses represent these areas. Proximity sensor information from previously described modules, such as, for example, modules  37   a  and  37   b  (FIG. 2) distributed along the controlled roadway of PTS  11 , report information to each local slave station. This information is continuously transmitted to Master station  95  enabling a complete real-time overview of traffic activity over the entire infrastructure of PTS  11 . 
     As previously briefly described, the Master computer station envisions the overall dynamic system as moving virtual spaces (PV packets) on a continuous basis. The number of such moving spaces is a function of the size and capacity of the PTS. The Master system moves the virtual PV packets at a constant speed throughout the controlled roadway system, and knows at all times the position of each space. As spaces are manipulated in the system to traverse the system at a constant speed, the Master system can anticipate (forecast) the position of each space at any point in time. 
     Each PV packet moving in the system is logged by the Master system as occupied or not occupied by a PV at any instant in time. For example, the Master system forecasts a coming unoccupied space or group of spaces when a PV or packet of PVs is ready to enter the controlled roadway. The ready PV or packet is then controlled to coincide with the forecasted space or group of spaces, and at juncture, the virtual packets are logged by the system as occupied. 
     In response to logged and forecasted information (constantly checked and validated) main station  95  sends commands to individual OBC&#39;s either directly, or through associated slave stations. The commands to OBC&#39;s will mainly focus on cooperation with proximity sensing systems to orchestrate entry and exit to and from the PTS. A unique switching system and process is described below for switching PVs at junctions. Other commands and communication may include instructions for linking PVs together, informing passengers of current status in route, and so on. 
     In one embodiment, computer operators (not shown) are provided at station  95  as observers similar in some respects to air traffic controllers. Such operators may, in some instances, have override control capabilities that may be exerted in case of an emergency such as a failure on a portion of the system. As an example of such a situation, consider that a portion of PTS  11  in-between stations  89  and  93  has failed due to damage or excessive debris caused by a catastrophic weather event. Operators at station  95  would be able to cause all traffic to exit PTS  11  at stations  89  and at stations  93  whereupon such traffic may then travel on normal roadways to an undamaged area of PTS  11  and re-enter the system. 
     In one embodiment, a Master station such as station  95  may communicate and collaborate with a separate PTS system having a separate Master control station. This capability is illustrated in the embodiment by satellite  99  and associated communication icons. In this way, PVs may be advised prior to entering a PTS system such as system  11  that another nearby system has less traffic or wait time to enter. 
     Mobile-aid Apparatus and Methods 
     One of the advantageous features in embodiments of the present invention is that all systems are kept as simple as possible. The controlled roadway, for example, has no apparatus for providing power to vehicles, or for charging vehicle batteries or refueling vehicles. There need not be, therefore, expensive and fragile electrical system integrated with the roadway. The roadway itself is a simple assembly of passive paths over which PVs may operate. Similarly there need not be elaborate switching systems because the vehicles not only travel under their own power, but also under their own steering systems. 
     In this philosophy each PV is expected to come onto a controlled roadway with more than adequate potential energy to complete a predetermined trip. In the case of EVs, for example, the potential energy is the charge of the on-board batteries that power the PV. In the case of internal combustion power plants, the potential energy is the fuel load at the start of a trip. As described elsewhere in this specification, this means checks must be put in place to determine the potential energy resources of each PV entering the system. 
     The inventors recognize that there is a tradeoff in the simple philosophy adopted for embodiments of the present invention. To keep the roadway as simple as possible the range of PVs traveling on the roadway will be restricted, perhaps effecting overall applicability of the system. The inventors recognize as well, that the greatest impediment to forward travel for most vehicles, whether on a surface street or a controlled roadway such as proposed herein, is air friction. A great amount of energy is expended accelerating a vehicle to cruise speed, but once the speed is attained, the greater part of energy requirement is to maintain the speed against air resistance. Friction is a lesser retarding factor. Therefore, knowing that PVs traveling together in close proximity may create mutual draft, the total energy requirement for each V may be reduced by causing the PVs to travel in close proximity. There are also other ways the energy requirement may be reduced. 
     FIG. 2B is a cross-section similar to that of FIG. 2A, showing coverings  14  and  16  over each oppositely directed lane. These coverings do not render the structure more complex, as they are also essentially passive, but provide in such embodiments several advantages. One is simply that rain, snow and sleet, and also unwanted debris, is kept off the controlled roadway. Another is that the air in each thus-created tube, will tend to keep moving in the direction of the travel of PVs and groups of PVs, thereby reducing the energy requirement for a PV to make a particular trip. Once the air is moving in one direction, it will tend to keep moving in that direction, and there will relatively less air friction for PVs traveling in the system. 
     In another embodiment air pumps (illustrated by element are provided at intervals along the controlled roadway for the purpose of injecting air into the tube to move the body of air in the enclosed tubeway in the direction of the moving PVs, further reducing the potential energy requirement for each PV to make a trip. In alternative embodiments such air pumps may be mounted in different places, on the surface away from the structure, or within tube  19 . A skilled artisan will understand that moving air may be applied in a variety of different ways. Also, air movement may be promoted by pumps providing partial vacuum as well as forced air. 
     Personal Vehicle 
     Referring again to FIG. 4 of this specification, PV  15  is described as a self-powered, dual-mode vehicle, which may be of a standard or new design. The embodiment of FIG. 4 shows PV  15  as a dual-mode electric vehicle (EV) with the term dual-mode referring to two methods of vehicle control (user control and system control). The power source for PV  15  as exemplified in FIG. 4 is rechargeable batteries. 
     In other aspects of the present invention, a potential power source for PV  15  other than electricity may be provided without departing from the spirit and scope of the present invention. Some other possible power sources include, but are not limited to, combustible liquid fuel, combustible dry fuel, solar-sourced electricity, or the like. Internal engine components would of course be compatible to the type of power source implemented. Dual-mode power sources are also possible. For example, PV  15  may use liquid fuel when traveling off of PTS  11  while using electricity when traveling on PTS  11 . In another embodiment PV  15  runs on menthol fuel both on and off the PTS system. There are many alternative possibilities. The advantages of and features of the invention are not limited to one type of power for a PV. 
     PV  15  of FIG. 4 is approximately 10′ long×5′ wide in an exemplary embodiment. The dimensions cited are not to be construed as a limitation, but only as preferred size for obtaining an optimal “traffic load” on PTS  11  without sacrificing commuter comfort. Many differing designs may be used for PV  15  as previously described. In FIG. 4, the design is similar to a well-known mini-wagon. If a longer vehicle such as PV  17  of FIG. 1 is used, preferably, it is used in integration with compact passenger PVs such as PV  15 . 
     In a preferred embodiment, the construction of each PV is standardized such that many different manufacturers may produce such vehicles in a competitive fashion, and all may be used on a PTS according to embodiments of the present invention. As a result, differing designs may be manufactured for PTS  11  as long as dimensional and functional requirements are met for traveling on the system. 
     Vehicle On-board Computer (OBC) 
     Every PV such as PV  15  described above, is equipped with an OBC such as OBC  73  of FIG.  4 . In a preferred embodiment, complete control of PV  15  may be transferred to PTS  11  while the vehicle is engaged on the controlled roadway of PTS  11 . An exemplary OBC system is described in enabling detail below. 
     FIG. 6 is a block diagram of OBC  73  of FIG. 4 illustrating various required and optional components. OBC  73  is a relatively powerful and dedicated computer system for controlling various PV systems and communicating with main computer stations such as with previously described slave stations (FIG. 5, elements  87 - 89 ) and a Master station (FIG. 5, element  95 ), which oversees the entire PTS system. A preferred method of communication for OBC  73  is a high bandwidth-capable wireless data-packet network illustrated as network  97  of FIG.  5 . 
     Each OBC such as OBC  73  has it&#39;s own network address as is known in the art of wireless and other forms of network communication. Each address is a unique identifier, and also identifies the PV carrying the OBC. OBC  73  has a system bios  103 , a CPU  105 , and at least one suitable memory module  107 . System bios  103  provides system boot capability and loads various required routines to CPU  105  and memory module  107 . Such routines may include a pre-boot test of OBC components, operating system loading, and other known routines common with computer systems. CPU  105  has a processing speed suitable for the dedicated operations of OBC  73 . CPU  105  must be fast enough to enable multitasked continual routines performed by OBC  73  such as steering, speed adjustment, proximity sensing and reporting, and the like. Recent developments in processing capability will provide processors with speeds up to 1000 MHz to be implemented in computer systems within a short time frame. 
     CPU  105  provides system commands in a multitasking environment such that many functions may be performed simultaneously as required during operation of PV  15 . Memory module  107  holds software programs, such as a unique PTS operating system, temporary cached instructions, and other required data. Memory types may be any suitable mix of volatile and non-volatile memory including RAM, ROM, Flash memory, and so on. 
     In one embodiment, some memory may be provided in removable units such as a PC memory card. In this case, such cards may be removed from OBC  73  when not in use and plugged into a desk-top computer or other facility for the purpose of adding programming instruction, reporting status, upgrading functionality, and so on. In this way, certain instructions and intentions may be communicated to PTS  11  via a desktop computer with an Internet connection, or perhaps, via an accessible network-connected computer terminal adapted to communicate with such cards. Such a computer terminal may simply be located at an embarking location such as station  49  of FIG. 3, or alternatively, at any convenient public location such as an airport, job site, or other public locations. In this way, travel requests and the like may be pre-ordered and stored such that when PV  15  arrives at a station such as station  49  of FIG. 3, travel parameters and authorization parameters are already approved and only diagnostic functions related to mechanical integrity and the like need be performed. 
     In other embodiments the relationship between OBCs  73  for all PVs and the Master computer system is such that the Master maintains a real-time status on every PV qualified to use the controlled roadway(s) controlled by the Master system. In this architecture communication between Master system and OBCs is wireless through a leased or dedicated cell network, preferably of a data-packet nature. For this architecture OBCs for active PVs are preferably never turned off, but rather put into a sleep mode. The Master system may wake up any OBC within its communication range, and update data and functions with that OBC. In this architecture the Master system on a scheduled basis accesses records maintained by each OBC for each PV, and updates its own database as to, for example, suitability of a PV for authorization to enter a controlled roadway through an access station. More detail of the overall computer system nature for such an architecture is provided below. 
     In another aspect, also described in more detain below, not only is every PV through an OBC in frequent communication with the Master system, whether on a controlled roadway or not, but the Master, through an Internet site, also provides a WEB interface for commuters to interact using a desk-top computer, a laptop, or other Internet-capable appliance such as a personal organizer. In this system, also described in more detail below, a commuter may log a next day&#39;s access and travel plans for a controlled roadway on a previous evening, or in the morning before leaving for work or on another trip, by interfacing with a personalized WEB page maintained and managed by the Master computer system. Many other functions may be implemented via such WEB interaction as well, and, again, more detail is provided below in another section. 
     Referring now back to FIG. 6, OBC  73  has a communication module  111  that is adapted to enable communication according to appropriate protocol with local slave computers such as at station  70  of FIG.  3  and/or with a Master computer such as computer system  95  of FIG.  5 . Module  111  has all the required circuitry and uses appropriate software programs necessary for such communication. Integration with elements of a cellular telephone system may, for example be used to provide wireless communication. In this case, as briefly described above, the wireless system is preferably a wireless packet data system, which allows real-time communication between many different locations, such as is the case with a large number of PVs having OBCs together with a Master system and a number of local slave systems. 
     An internal bus structure  113  is provided and adapted to link all digital components and systems to CPU  105  and other required internal components. Bus structure  113  may be any type of suitable bus structure capable of relaying all communications according to appropriate protocol, and in preferred embodiments is an industry standard bus of one of several known types. There are many types of suitable bus structures known in the art and suitable for the purposes of the present invention as one with skill in the art will readily appreciate. 
     OBC  73  uses a plurality of input/output interface modules to enable data transfer and communication to and from various external systems and components. Each of these components is described separately below; however, several such components may be grouped to a single I/O module without departing from the spirit and scope of the present invention. The inventor chooses to isolate (one I/O to one component) various components for illustrative purposes only. 
     A braking system (B/S) module  115  is connected to bus  113  and provides I/O communication means from OBC  73  to a PV breaking system (not shown). A braking system for PV  15  may use hydraulic technology or other known mechanical means. In computer-controlled operation CPU, executing suitable code, operates the PV braking system, and while the PV is under control of a commuter on such as surface roadways away from the controlled roadway(s), the braking system will be under control of the commuter/driver, as in any other such independently powered and operated vehicle. Such dual control capability allows each PV to e manually controlled under certain circumstances by a commuter, and to be appropriately directed by the Master computer system while engaged with a controlled roadway. 
     A velocity control system (V/S) module  117  is connected to bus  113  and provides an I/O communication means from OBC  73  to a PV velocity control system. A velocity control system for PV  15  will vary in implementation depending upon the nature of the power source and drive mechanisms. Again the nature of the control is dual, either computer or manual, but never both. 
     A PV implemented as an EV and powered by batteries such as is illustrated herein and in FIG. 4 will use a variable power distribution system to control the amount of power to an electric drive mechanism in order to affect acceleration and deceleration. Such control systems are known in the art and therefore are not described in detail in this specification. Such velocity control may also be used for braking, precluding need for a separate braking system in some cases. 
     A steering-control system (S/S) module  119  is connected to bus  113  and provides an I/O communication means from OBC  73  to a PV steering control system. A steering system for PV  15  may consist of a modified power-steering mechanism that may be actuated by OBC  73  in order to affect slight adjustments in steering. Power-steering mechanisms are well known in the vehicle industry and may be suitably modified with available components to accept automated robotic control. 
     A coupling-system (C/S) module  121  is connected to bus  113  and provides an I/O communication means from OBC  73  to a PV coupling control system. A physical coupling system for PV  15  may be provided as described in FIG.  4 . Elements of a coupling system may include an extendible engagement-member (FIG. 4.,  83   a ), a coupling receptacle (FIG. 4.,  83   b ), and a hydraulic system for extension and retraction (FIG. 4.,  81 ). More detail regarding a PV coupling system such as the one described in FIG. 4 is provided later in this specification. 
     An electrical system (E/S) module  123  is connected to bus  113  and provides an I/O communication means from OBC  73  to various PV electrical systems (not shown). Such systems may include but are not limited to headlights, taillights, turn lights, emergency flashers, interior lights, etc. Other electrical systems may include entertainment systems such as CD-stereo components, air-conditioning/heating systems, and so on. 
     A proximity-sensor system (PR/S) module  125  is connected to bus  113  and provides an I/O communication means from OBC  73  to various installed proximity sensors such as sensors  35   b  of FIG.  4 . In FIG. 4, proximity sensors  35   b  are illustrated as installed on the side of PV  15 , and are adapted to communicate with roadway barriers or proximity modules as described in FIG.  4 . However, sensors may also be provided for sensing distance between a first PV and other PVs ahead and behind. Sensors may also be provided and adapted to sense position on the roadway as related to wheel-travel surfaces and grated portions of the roadway. Input data received from various proximity sensors is used by OBC  73  to formulate required output parameters for modules  115 ,  117  and  119 . 
     In some instances, some proximity data is reported to a Master system such as system  95  of FIG. 5 by local stations such as stations  87 - 93  of FIG. 5 while receiving collective input from individual OBCs in a control vicinity. Master system  95  may thus keep an overall picture of traffic positioning on PTS  11  and make further needed adjustments by way of command back to local stations and then to OBCs, or directly to OBCs. Proximity sensors may use radar, photoelectric, or other means, as are known in the art. There are, as well, various reporting and correction schemes possible, some of which will be described later in this specification. 
     Referring back to FIG. 6, a vehicle diagnostic test (VDT) module  133  is connected to bus  113  and provides an I/O communication means from OBC  73  to specially adapted test equipment and diagnostic systems of a PV diagnostic facility such as facility  55  of FIG.  3 . Such equipment may test wheel alignment, external operating condition of PV systems, current capacity (charge state) of batteries, status of cooling system, and so on. OBC  73  acts as an interface between installed PV systems and such diagnostic equipment. 
     A passenger diagnostic test (PDT) module  131  is connected to bus  113  and provides an I/O communication means between OBC  73  and any special inquiry systems and/or automated detection equipment that may be in use at a staging location such as at facility  55 . For example, automated queries concerning passenger fitness including phobias, current medications, and medical conditions, disabilities or the like may be transferred to OBC  73 . OBC  73  may already have the required response information stored and may, in most instances, complete the transaction without the aid or participation of a passenger. This is especially true if the passenger is a frequent traveler on PTS  11 . An automated device for checking any intoxication levels, such as a breath analyzer, may be installed as an automated detection device of PV  15 . OBC  73  may communicate results through module  131 . System queries and tests directed to passenger condition and status are not meant to be an intrusion, rather such conventions help to insure safety on PTS  11 . 
     In one embodiment, a passenger will have to provide some input into a response to a medical or fitness query as described above. A passenger-interface system (PI/S) module  139  is provided and connected to bus  113 . PI/S module  139  is adapted to enable a voice-to-data and data-to-voice I/O means between a passenger and OBC  73 . In this way, a passenger may provide requested information not already stored on OBC  73  for use with other systems such as diagnostic systems or query systems as described above. Moreover, module  139  may be used for emergency reporting to a slave or Master system. Module  139  uses voice recognition technology known in the art. 
     Regardless of the communication scheme used between OBCs and a Master system, it is desired that a single master computer system such as system  95  of FIG. 5 retain a complete real-time knowledge and control over all traffic existing on PTS  11  at any given moment. Such knowledge includes current speed parameters including entrance and exit speeds, merge parameters including knowledge of available merge spacing between PVs and PV groups. Other statistics include knowledge of the number of units traveling on the system, knowledge of roadway conditions and weather factors, knowledge of ongoing maintenance and any resulting changes in system operation and performance, and so on. 
     Power to OBC  73  is supplied by conventional battery means as described in FIG. 4. A power cut-off (C/O) module  127  is connected to bus  113  and provides input instruction to OBC  73  to disconnect or reconnect (if disconnected) from an external power supply such as batteries. This enables OBC  73  to be serviced safely. A technician may access module  127  through a switching means (not shown) placed in a convenient location such as under the hood, or from inside PV  15 . 
     It will be apparent to one with skill in the art that OBC  73  may be equipped with more or fewer modules of varying function than is illustrated in this embodiment without departing from the spirit and scope of the present invention. It will also be apparent to one with skill in the art that OBC  73  may have different functionality for interacting with different propulsion systems such as may be evident in PV vehicles using alternate power sources. There are many variable possibilities. 
     Referring now back to FIG. 4, PV  15  is described as having a physical coupling system adapted to enable PVs to be physically linked together successively. An exemplary coupling system for PV  15  is detailed below. 
     Vehicle Coupling System (VCS) 
     FIG. 7 is an elevation view of a vehicle coupling system (VCS) according to an embodiment of the present invention. An exemplary coupling system comprises an extendable member  83   a  and coupling receptacle  83   b  as previously described briefly in FIG.  4 . In this embodiment, a PV 2  is illustrated as presenting member  83   a  in a state of extension in preparation for coupling to a PV 1  with the aid of receptacle  83   b . In this way, a plurality of PVs may be coupled together in a line or group. Extendable member  83   a  is hydraulically operated in a preferred embodiment. However, other means of mechanical extension may also be used. 
     The extension apparatus comprises at least two members  83   a  and  83   b  arranged as an extensible/collapsible tube as in known in the art, which may be extended or contracted hydraulically, mechanically or pneumatically in various embodiments. 
     Tube  148  has a plurality of retractable coupling extensions  145  pivotally mounted to the coupling end. Extensions  145  are, in this embodiment, spring-loaded and adapted to be partially urged into the interior of tube  148  upon physical depression thereof such that their outside diameter becomes small enough to fit into the cylindrical bore of receptacle  83   b . A mechanical means (not shown) for retracting extensions  145  against the force of loaded springs is also provided so that de-coupling may be effected. 
     The formation of extensions  145  at the coupling end of tube  148  assumes a conical shape so that a suitable tolerance variation with respect to the alignment of member  83   a  to receptacle  83   b  may be allowable. Member  83   a  is provided a small amount of flexibility that allows for a slight misalignment without affecting the coupling process. In this way, PVs such as PV 1  and PV 2  need not be perfectly aligned to each other in order to effect successful coupling. Coupling is achieved as PV 2  and PV 1  are traveling in collinear arrangement and suitably aligned (within allowable tolerance) to each other. 
     A receptacle housing  153  provides rigid support for receptacle  83   b  and retainers  146 . Housing  153  may be mounted in a rigid position to the frame of a PV such that the bore of receptacle  83   b  is presented at the same height from the roadway as member  83   a . Housing  153  may be cylindrical or rectangular in cross section with a center bore of receptacle  83   b  extending therein. 
     A plurality of retainers  146  are located near the rear portion of receptacle  83   b  and are adapted to accept extensions  145 . Extensions  145  and associated retainers  146  are rigidly positioned to coexist in the same spatial arrangement aligned so that no rotation of member  83   a  is required during coupling. In an alternative embodiment, member  83   a  is rotatable in a clockwise or counter clockwise direction. In this alternative arrangement, extensions  145  may be brought into alignment with retainers  146  by rotation. Retainers  146  are formed in the solid mass surrounding the center bore. Spring force urges extensions  145  into retainers  146  as member  83   a  reaches a certain coupling depth into the bore of receptacle  83   b . At this point coupling is achieved and the PVs are locked together. Member  83   a  is caused to reach a coupling depth as a combined result of the hydraulic extension of member  83   a  and any necessary deceleration or acceleration on the part of either PV  1  or PV  2  during transit. 
     Hydraulic pump  81  provides a means for extending member  83   a  as described in FIG. 4. A control line  149  is provided to enable OBC control of coupling. A power line  151  is provided for connecting pump  81  to a power source such as batteries  87  of FIG. 4. A sensor line  155  is provided and adapted to connect receptacle  83   b  to an OBC such as OBC  73  in PV 1 . A suitable sensor or sensors (not shown) is provided at the rear of receptacle  83   b  and is adapted to sense when coupling is completed and when de-coupling is completed. There are many sensing methods known in the art that are suitable for this purpose, such as switch-activated sensors, or the like. 
     In a preferred embodiment, coupling during motion or transit is achieved while PVs  1  and  2  are traveling at a constant speed at a specified distance from each other such that only hydraulic extension of member  83   a  need be activated to effect successful coupling. Preferably, the distance between PVs  1  and  2  after coupling is  12 ″ or less. This aids in maximizing efficiency related to total traffic load on PTS  11 , and supports a more durable coupling with respect to any side-to-side movement by any coupled PV. PVs may, of course, be coupled when one or both PVs are stationary. Furthermore, many more than two vehicles may be coupled together. 
     In one embodiment, a means for sharing OBC control between two or more vehicles may be achieved by coupling the vehicles. In this embodiment there are connectors at each coupling point adapted to link successive control communication lines such that one contiguous control line is created whereby control over several vehicles may be designated to one OBC system. This may be beneficial for controlling coupled groups of PVs. Similarly, one controlling OBC may designate a constant speed to several coupled PVs thus lessening load forces on each PV. Coupling may also be used in some embodiments for hauling freight in specially designed PVs adapted for the purpose. Coupling may also be used to tow disabled vehicles, or when an emergency calls for evacuation of PTS  11 . 
     It will be apparent to one with skill in the art that many other designs and mechanical methods for coupling vehicles may be incorporated herein without departing from the spirit and scope of the present invention. The inventor intends the coupling system represented in the above embodiments to be exemplary of only one possible variant of multiple possibilities. 
     Proximity Sensing System (PSS) 
     In a preferred embodiment of the present invention, PVs such as PV  15  of FIG. 4 navigate with the aid of a proximity sensing system. Each proximity system is a system comprising sub-systems responsible for gathering and analyzing different classes of data used to adjust separate functional systems on a PV such as steering and speed. 
     Referring now to FIG. 2, proximity sensors-sets  35   a  and  35   b  are illustrated and adapted to communicate in one embodiment with target modules  37   a  and  37   b  that are placed incrementally along the sides and center barrier of roadway section  13 . In this embodiment, a separate reporting system linked to the roadway modules is responsible for reporting certain parameters to a master control station such as station  95  of FIG.  5 . Such a reporting system may be such as local controlling computer stations  87 - 93  of FIG.  5 . Such reports may contain parameters such as PV line location, available space parameters between separate lines of PVs, PV speed and so on. In this embodiment, sensing capability may be attributed to the roadway modules themselves with each module wired to a central module that reports to a local station. All local stations report to a master station as previously described in FIG.  5 . 
     In another preferred embodiment the proximity sensors are of a sort that operate entirely from the PV, capable of sensing proximity and distance from proximate surfaces, such as barriers along the controlled roadway. In this embodiment no roadway-mounted modules are needed, therefore no wiring in the roadway for such modules. 
     The advantage of proximity sensing is that PVs may use proximity data to adjust steering, for example, to maintain lateral position in the controlled roadway. Identification and reporting of other parameters associated with PV position related to the PTS system as a whole or to other PVs, such as available space between PV lines or groups, etc. may be accomplished by each OBC in cooperation with proximity sensors. In other embodiments some functions, such as absolute position of a PV relative to the controlled roadway may be delegated to the roadway system and local control stations. Reports in this instance are created as traffic passes sets of roadway sensing and reporting modules in real time. By using this type of proximity sensing system, the speed of PVs or PV lines does not necessarily have to remain constant as continuous reporting to a master computer provides an overall view of activity on PTS  11 . Commands from the master computer to individual OBCs, such as to adjust individual speeds take into account collective data related to other PVs in the vicinity such that appropriate adjustments may be effected. 
     In one embodiment reflectors and the like are placed incrementally and distributed along roadway  13  such that sensors  35   a  and  35   b  may. In addition to range, gauge speed and longitudinal position along PTS  11 , perhaps using a photoelectric technology incorporated in addition to radar range detection technology. This will allow passing PVs to determine their own speed and absolute position along PTS  11 , as well as distance between lateral barriers for automatic steering. 
     In one preferred embodiment the master computer maintains a distributed map of the controlled roadways and logically moves virtual spaces at a constant speed and standard spacing. The virtual spaces in this specification are termed PV packets. Each virtual PV packet has an identification number and a standard size, derived from the standard size of PVs accommodated by the system. The Master computer moves virtual packets at a constant and standard speed in the system, which, in examples in this specification is 68 miles per hour, equating to 100 feet per second. Entrance and exit ramps are also included in the virtual map to at least a point of a pre-merge constant speed-zone or safety zone. In this embodiment the Master computer marks PV packets as being occupied or not occupied at all times, enabled via continual reporting and known information. Merging traffic entering the system must attain the predetermined constant speed and merge into an unoccupied virtual space, which the Master then marks as occupied. In this way, data may be communicated to PVs waiting to enter the controlled roadway such as when to initiate movement to progress onto the system, and what ramp acceleration is required in order to place a PV in an appropriate position to merge with an assigned PV packet. 
     In this embodiment, sensors are still used as described in previous embodiments, but the data gathered by the sensors is chiefly used to double-check PV absolute positioning against PTS-assigned position, so appropriate adjustments may be made. For example, each entrance loop such as loops  53   a  and  53   b  of FIG. 3 has a pre-determined length, and PVs are expected to be traveling at the system constant speed in order to meet an assigned virtual ramp packet that coincides with an assigned passing packet. This section of each entrance loop is a safety zone as previously described. OBCs of PVs, using proximity sensors and position markers on ramps sense absolute position and adjust acceleration to match assigned packets to merge into the system. 
     In addition to proximity sensors that obtain data from side barriers for steering, a set of proximity sensors may also be provided and adapted to sense certain features in the roadway underneath the PV such as the inner edges of contact surfaces  46  of FIG.  2 . Other sensors such as a front to rear sensor for maintaining a constant space between each PV may also be provided as previously described. 
     FIG. 8 is an end view of PV  15  illustrating various installed sensors and connections comprising a proximity sensing system (PSS) for sensing PV proximity in a travel lane, position along PTS  11 , and speed of individual PVs. PV  15  is illustrated in appropriate transit position within a travel lane that is part of controlled roadway  13 . Wheels  75  of PV  15  are, in this example, positioned on raised contact surfaces  46  as described with reference to FIG. 2 above. 
     Proximity sensor sets  157  and  159  (two sensors each side of PV  15 ) are analogous to sensor sets  35   a  and  35   b  of FIG.  2 . Sensors  157  and  159  are adapted to detect and sense distance from side barrier surfaces. As previously described, radar technology is used in this example, along with a photoelectric technology used to sense incremental roadway markers  158  and  160 . 
     In this exemplary embodiment, sensor sets  157  and  159  are adapted to sense distance to each roadway barrier using radar technology. Sensor sets  157  and  159  are also adapted to sense roadway markers  158  and  159  using photoelectric technology for the purpose of determining the speed and absolute position of PV  15  along PTS  11 . Therefore, sensors  157  and  159  are in effect dually-capable proximity sensors. 
     Data received by sensors  157  and  159  and all necessary communication between the sensors and OBC  73  is by way of lines  175 . By utilizing sensors  157  and  159 , OBC  73  may accurately and continuously determine PV position between the barriers of roadway  13  with significant accuracy. Moreover, accurate vehicle speed and longitudinal position (absolute position in the PTS) along roadway  13  may also be determined by photoelectric interaction with roadway markers  158  and  159 , which are placed periodically along barriers as previously described. 
     The operating system of OBC  73  causes continuous series of measurements to be accomplished using the proximity sensors on a cyclic basis, at least several times per second, such the OBC essentially has a continuous real-time knowledge of the position of the PV in the roadway relative to the side barriers. This information is used by CPU  105  (FIG. 6) to control steering through I/O module  119  to keep the PV properly centered in the roadway as the PV travels along the controlled roadway. 
     Additional proximity sensors  163  and  165  may in some embodiments be provided and mounted at strategic locations on the undercarriage of PV  15 . Sensors  163  and  165  may be positioned as four individual sensors, two in front (one driver side and one passenger side) and two in the rear (same configuration). Sensors  163  and  165  use radar technology like sensors  157  and  159 . Sensors  163  and  165  are focused on and adapted to detect the opposite existing edges (from each sensor) of raised contact surfaces  46  as illustrated by the double arrows underneath PV  15 . This is possible because contact surfaces  46  are of a solid nature, raised, and not grated, as is the rest of roadway  13 . In this way, additional range data may be incorporated with range data from sensors  157  and  159  in order to further reduce a margin of error. Furthermore, if an area or section of PTS  11  has no installed barriers by design, or circumstance, the undercarriage proximity system represented by sensors  163  and  165  may be used in place of sensors  157  and  159 . 
     Two examples have been provided illustrating use of proximity sensing for automatic steering control for a PV on a controlled roadway as taught. Other systems may be used as well, such as an underneath-mounted sensor adapted to follow a powered center line in the roadway. It will be apparent to those with skill in the art that the side-to-side control system using such sensors may be implemented in a number of ways. Control lines  175  provide connection between OBC  73  and sensors  163  and  165  as previously described with side-mount sensors  157  and  159 . 
     In an embodiment wherein several PVs may travel together in a group on a controlled roadway in close proximity, with perhaps only a foot or so between successive PVs, a method is needed to judge and maintain the spacing between each PV traveling in a group, in lieu of coupling the PVs together. Therefore, front and rear proximity sensors  161  (front sensor shown) are provided and adapted for the purpose. Radar sensors may be used in this embodiment as well. A control line  177  provides a communication connection between sensor  161  and OBC  73 . Sensor  161  (rear sensor) may be mounted above coupling receptacle  83   b  as is shown here, or in any preferably centralized location on the rear surface of PV  15 . Similar parameters are assumed for mounting of the front sensor. 
     In sensing spacing between PVs in a group and traveling on a controlled roadway at a constant speed, it is noted that the responsibility for adjusting speed is, in a preferred embodiment, a responsibility of each OBC. Automatic speed adjustment for a PV, managed by the OBC, is in response to several inputs. For example, each OBC has constantly updated data from sensors that indicate the PV absolute position in the controlled roadway at any point in time. This means the precise point at any instant along the traveled lane. The OBC also has real-time data as to the distance to the next PV ahead and the next PV behind. All of this is real-time data relating to where the PV is. Now, from the Master computer, which moves virtual packets and directs real PVs to occupy packets, the PV may know precisely where it ought to be in absolute position at any instant. 
     Given the above, the OBC for each PV, adjusts its own power, braking, etc. to stay within the PV packet assigned by the Master system in a safe manner. That is, a constant string of real-time data is available for the PV to know if it is, in fact, squarely within the assigned packet space, if it is gaining or falling back, and so forth. There is also data in many instances as to the relative position of PVs ahead and behind. So there may be a situation, for example, where a PV traveling along a controlled roadway, constantly checking its own absolute position and in constant communication with the Master system, knows it is 1 foot behind its assigned virtual packet space; and its forward sensor tells the OBC that there is a PV in front at a 10 inch distance. Clearly the PV cannot move up the required one foot. Conflict resolution code procedures are constantly available, so the PV may query the Master for instruction, and the Master can arbitrate correcting the position of the forward PV so the instant PV may then correct its own position. 
     The skilled artisan will recognize that the above example is just one example of many which may be arbitrated by the Master system between operations of individual PVs. The salient feature of the invention in this respect is that the Master system exercises Master control by moving its virtual PV packets, assigning spaces to real PVs, aiding the oncoming PVs to occupy the spaces, and then aiding the PVs to maintain their assigned spaces as long as necessary. 
     There are a number of ways as well that a PV may determine its absolute position on a controlled roadway. One method, described briefly above, entails side sensors of a PV recognizing fixed markers in side barriers. Such markers may be planted or mounted at increments, such as one packet length, along each controlled roadway lane, and a PV knows through sensing and communicating to the OBC the precise instant a known marker is passed. Estimates may then be forecast by the OBC and checked at each detection of a new absolute marker. Counting of markers may also be used. 
     It will be apparent to one with skill in the art that there are other embodiments of travel on PTS  11  that may not require some aspects of proximity sensing without departing from the spirit and scope of the present invention. For example, in one embodiment PVs may always travel in coupled groups thereby precluding the requirement for front and rear proximity sensors. In this embodiment spacing between groups (considerably more than 10 inches) would be determined and maintained by side-mounted sensors such as sensors  157  and  159 . Further, one OBC in a group may be designated a control Master for the group, and exercise control over power and braking functions for other PVs in the group. In still another embodiment that was described above, some sensing responsibility is delegated to a roadway system comprising of powered modules that reports to local control stations such as station  70  of FIG.  3 . There are many such possibilities. 
     Use of Proximity Sensors in Text Switching 
     The proximity sensing system described above may also, in an embodiment of the invention, be used to effect successful switching in and out of lanes in a controlled roadway for such as exiting PTS  11  without requiring mechanical switching apparatus. A method for effecting turning by selective powering of sensors described in detail below. 
     FIG. 9 is a diagrammatic plan view of an exemplary section  180  of controlled roadway in an embodiment of the invention illustrating PV exiting capability by selectively following proximity sensor data. In this example, section  180  has two exit lanes  182  and  184 . In the uppermost exit lane  182  there is a PV group  179  comprising individual PVs a-e progressing in unison down the exit lane. At the other exit lane  184  individual PVs g-j (indicated as group  181 ) is illustrated with two PVs f and h staying on main roadway  13  while PVs g, i, and j are exiting as illustrated. A group  183  of PVs comprising a lead PV k followed by four PVs labeled x is illustrated on roadway  13  just prior to reaching exit lane  184 . 
     This unique switching system for exit lanes is enabled by the system of proximity sensing and computer steering control described above, wherein PVs are steered to maintain a central position between side barriers. Consider now PVk at the head of exit lane  184 . PVk may be destined to exit at  184 , to continue and exit at  182 , or to continue past both these exits and leave at some exit further down the line. The exit method described herein depends on the maintenance by each OBC for each PV of an absolute position in the road way system, and the default of every PV having booked a travel itinerary. The OBC and the Master system, then, both know the absolute position of PVk as it moves and the exit ramp it is to use. 
     Assume for exemplary purposes that the pre-booked travel itinerary for PVk calls for exit at ramp  182 . By tracking absolute position both the OBC for PVk and the Master system know exactly when PVk approaches exit ramp  184 . At some distance prior to the exit the OBC with approval of the Master switches to steering control by only the right-side proximity sensor(s). Now, for a short period, steering of PVk is controlled to keep PVk at a fixed distance from the right side barrier, which follows the exit ramp (the left side barrier goes straight). PVk will then be caused to follow the exit. 
     As absolute position data indicates PVk is wholly within the exit lane, where a left side barrier is again available to follow, the OBC, with Master approval, again enables steering to both side sensors, and PVk proceeds down exit ramp  184 . 
     Assume now that PVk is planned by its itinerary to pass exit  184  and to take exit  182 . By virtue of this pre-data and known absolute position, PVk will steer only by left side data to pass exit  184 , and then continue on left-side data to take exit ramp  182 , after which both-side steering will again be enabled. 
     In the event PVk is to pass both exits, left-side steering would be enables to pass exit  184 , then right-side steering to pass exit  182 , then both sides again to continue normally down the controlled roadway. 
     Clearly the switching of steering between proximity sensor data is necessary for every PV at and near every exit, so PVs take only the correct exits. 
     These rules may change, however, if there is an emergency situation and a PV must make a non-designated exit from PTS  11 . The Master system may of course make such amendments as circumstances require. 
     PVs entering PTS  11  will follow the same protocols as those exiting, accept that an entrance ramp will have a location such as  185  and  187  for powering off the appropriate side sensors when reaching the merging point where roadway  13  is at it&#39;s widest distance across. Locations  185  and  187  may comprise strategic points having special markers in the roadway that are recognizable by individual OBCs through function of the sensors. Perhaps a simple accounting of previously described roadway markers such as markers  160  will be sufficient for OBCs to recognize when to power off or on appropriate sensors. In another embodiment, OBC&#39;s are simply commanded by a master computer such as master station  95  of FIG. 5 when to power sensors on or off. In still another embodiment the commands may come from local stations such as station  7   o  of FIG.  3 . There are many possible variations on this command and control theme. 
     Methods for Entrance Switching 
     FIG. 10 is a plan view of a portion  191  of PTS  11  showing an entrance ramp  215  joining into a controlled roadway lane  193 , illustrating unique methods for integrating oncoming traffic into a controlled roadway. There will, of course be a number of such entrance ramps, with at least one at every interchange station associated with the PTS. In most cases each station will have at least two entrance ramps, one for each direction of travel (see FIG.  3 ). 
     As described above, in a preferred embodiment of the invention the Master computer system maintains a moving map of virtual PV packets, and marks these packets as occupied or unoccupied in real time. This real-time map of PV packets is the basis for al control and forecasting in the system. In FIG. 10 the virtual PV packets are shown as dotted rectangles. In this embodiment each packet moving in the map of controlled lanes, exclusive of entrance and exit lanes, has a primary unique identification. The specific identifier is not important to the invention, just that each packet moves at the controlled constant speed and is spaced from other packets fore and aft at the standard spacing. Examples of virtual PV packets moving in primary controlled lane  193  of the system are packets  211 ,  205 ,  207  and  213 . 
     At entrance and exit ramps the Master system may maintain duplicate PV packets to primary packets moving on the controlled roadway primary lanes. Packets  209 ,  203  and  211  are examples of such packets. These packets are called duplicate packets herein because each such packet is created as an adjunct to a primary packet, and they disappear as they merge with primary packets. For example, with the primary packets moving in the controlled roadway lane  193  in the direction of the arrow, as each primary packet approaches an entrance ramp the Master system creates an adjunct packet in the entrance ramp at a position and moving in a way that the adjunct packet will merge with a primary packet at the head of the ramp, in joining with the controlled roadway. 
     The adjunct packets created do not necessarily always move at the controlled roadway constant default speed (100 ft/sec in these examples), but may start from zero speed and accelerate to the standard speed at the point of merging with a primary packet. The acceleration used is within the capability of an actual PV. In FIG. 10 packet  209  is adjunct to packet  211  and will disappear as it merges with primary packet  211 . Packet  203  is similarly adjunct to primary packet  205 , and packet  211  is adjunct to primary packet  213 . Each of these adjunct packets will disappear as they merge with their respective primaries. 
     The creation of adjunct packets to passing primary packets is to provide a method for safely and efficiently merging actual PVs into traffic on the primary controlled roadway. Attention is drawn to the fact that packet  213  approaching on-ramp  215  is an occupied primary packet, and to merge an actual PV with this packet would be a disaster. Therefore the Master system marks adjunct packet  211  as “not to be occupied”. No actual PV will be started relative to adjunct packet  211  to merge with primary packet  213 . 
     Primary packet  207  is an unoccupied primary packet, and a PV was waiting to enter on ramp  215  at the proper time to be started relative to adjunct packet  195 . Therefore the PV was started and is controlled to occupy adjunct packet  211 . The OBC for the PVC occupying packet  195  operates to adjust the acceleration and speed of its PV to occupy and stay in packet  195  until packet  195  merges with packet  207  at the head of the ramp, at which time packet  195  disappears and the Master marks packet  207  as occupied. Now the OBC and Master system cooperate to maintain the PV in packet  207  until the packet and PV approach the pre-destined exit ramp. 
     In the merging process the PV occupying an adjunct packet is guided by the computers using the side sensors to a point in the ramp that, in this case, the right barrier ends, and then by the left barrier sensing only until fully on the primary controlled roadway, after which two-side control for steering may be re-enabled. 
     In the manner described above PVs at entrances and exits from the primary may be safely managed onto and off the primary roadways (see also FIG.  3 ). In this process there are also markers and other elements at the ramps enabling the OBCs of PVs to track their absolute position relative to the ramp and the primary roadway. The process of entering and exiting is a process of matching the absolute position with the virtual correct positions cast by the Master system, which may be copied in real time to the OBCs for control purposes. 
     Construction Apparatus and Methods 
     One object of the present invention is an ability to quickly and relatively inexpensively implement controlled roadways and to connect the resulting infrastructures to ancillary equipment to provide functioning PTS systems according to embodiments of the present invention. Some of the processes and procedures involved have been discussed briefly above with reference in particular to FIGS. 1,  2 A,  2 B, and  3 . 
     A feature of embodiments of the present invention that provides a distinct advantage in cost over existing and predicated systems is the fact that in most embodiments of the present invention the controlled roadway is a passive structure, designed to be modular in that sections between supports may be pre-constructed and assembled one-after-the-other, with pre-assembled structures transported over existing sections of the roadway. 
     FIG. 11 is an elevation view of a partially constructed roadway  301 , and a unique construction tool in the form of a traveling crane  303  for sequentially adding new roadway sections. In this view supports for the roadway have been put in place in advance, and supports  305 ,  307  and  309  are shown implemented at predetermined positions. Supports  305 ,  307  and  309  each sport a cradle  310  at the upper most point for accepting the shaped underside of the roadway. Cradle  310  is shaped to accommodate the shape of the underside of roadway sections. Supports  305 ,  307  and  309  have virtually identical construction and features. Note that the track of the supports in this case is in the median of a surface highway  311 . 
     Roadway  301  has been extended to a point carried by support  307  in FIG. 11, and crane  303  has moved forward to the end of roadway  301  such that crane boom  313  extends beyond next support  309 . Crane boom  313  is of a length to extend to a significant distance beyond next support  309 , and has an articulated end  315  with a gripper mechanism  317 . The articulated end is enabled to fold down and attach to next support  309 . 
     FIG. 12 illustrates crane boom  313  with articulated end  315  folded down with gripper  317  engaged with support  309 , such that support  309  may now support weight of a new roadway section to be carried temporarily by crane boom  313 . In this view a new roadway section  319  that has been brought forward on a suitable carrier running on the completed portion of roadway  301  has been attached to hanging supports  321  and  323  that are translatable on a track along boom  313 . The crane is enabled to feed the new roadway section  319 , supported by hanging supports  321  and  323 , out over the span between supports  307  and  309 . As this new roadway section is fed out along the boom the weight is supported by crane  303  on support  307  on one end, and by support  309 , by virtue of the articulated end of the crane boom engaged now to support  309 . 
     FIG. 13 is a view later than the view of FIG. 12, wherein section  319  has been lowered below crane boom  313  to align with the previously completed roadway, and to suitably engage both supports  307  and  309  and be fasted in place. Gripper mechanism  317  has been disengaged from support  309 , and articulated end  315  is raised up again. Now crane  303  may moved forward to a new position at the new end of the roadway (support  309 ), where yet another section  325  may be extended and put into place to extend the roadway further. 
     It will be apparent to the skilled artisan that in the example described the roadway sections need to be substantially straight. This is not, however a requirement or limitation, because curvatures for changes in direction of completed roadway may be pre-calculated and curved sections suitably manufactured and provided by suitable carriers along the completed portion of the roadway under construction, and the crane may be provided in a manner that allows curved sections of roadway to be fed out and lowered into position. 
     The method and apparatus just described for extending roadways in embodiments of the present invention provides a very fast and relatively inexpensive means for establishing controlled roadways between access stations in the system described herein. Manual crews may follow behind the roadway crane to add final amenities as required, so shortly after a last section is put in place a functioning roadway may be provided. 
     Summary 
     It will be apparent to the skilled artisan that there are a broad variety of alterations that may be made in the several embodiments of the present invention taught herein, without departing from the spirit and scope of the invention. There are for example, many way that PVs may be provided, many ways that the controlled roadway may be implemented, and many variations in control systems and access stations in different versions within the spirit and scope of the invention. Similarly there are any alterations in software that may be used in accomplishing particular embodiments of the present invention, and many physical variations in the actual computer platforms that might be used. The invention is to be limited only by the claims which follow.