Patent Publication Number: US-2020290482-A1

Title: Tracked electric vehicle systems

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 16/728,416, filed Dec. 27, 2019, which claims the benefit of priority to U.S. Provisional Patent Application No. 62/785,499, filed Dec. 27, 2018, the disclosures of which are incorporated by reference herein in their entireties. 
    
    
     FIELD 
     The disclosed technology relates generally to electrified roadway systems, and electric vehicles configured to operate on the roadway systems. 
     BACKGROUND 
     Battery-powered electric vehicles are gaining in popularity and use. Due to their zero emission of greenhouse gases and other airborne pollutants, electric vehicles are gaining widespread recognition as an environmentally friendly means of personal transportation that can reduce the carbon footprint of the user and combat global warming. 
     Electric vehicles currently use batteries as their source of electric power. Batteries provide electric vehicles with full mobility, and allow the vehicles to operate on existing roadway systems. Any battery, however, has a finite energy-storage capacity, and needs to be recharged upon being drawn down to a low charge state. Recharging can be a time-consuming process, often taking hours to accomplish. While overnight charging may be a convenient means of charging a battery after normal daily use, the need to recharge one or more times during a long-distance trip can add significantly to time required to complete the trip. Also, the need to locate and drive to a suitable charging station can further prolong the time needed to complete the trip. 
     Recent advances in battery technology have resulted in increases in the storage capacity of batteries, yielding improved driving ranges for electric vehicles. Even with such advances, however, any battery will have a finite limitation on its capacity to store electricity. Thus, the range of any electric vehicle using a battery as its sole power source always will be limited by the storage capacity of the battery. 
     Providing power to electric automobiles and other electric vehicles during travel along a roadway can provide the vehicles with virtually unlimited range. Supplying electricity to a moving automobile or like vehicle, however, presents substantial challenges. These challenges are due, in part, to the inherently de-centralized nature of automobile travel. Specifically, an automobile by its nature provides transportation for a very limited number of people, and typically is used transport drivers and passengers directly to their desired destination. Thus, thousands or even tens of thousands of automobiles, each traveling to a different destination, may be operating on a roadway system at any given time. Electrifying a roadway system to simultaneously power such large numbers of vehicles, most of which are traveling to different places, presents challenges relating to power distribution; power management; the safety of drivers, passengers, and pedestrians; etc. Thus, some of the primary advantages of the automobile actually make it difficult to transfer power to an automobile while it is motion. 
     Although electrified railway systems have been operating successfully for decades, automobile travel is markedly different than rail travel due to the centralized nature of rail travel. For example, the TGV family of high-speed passenger trains in France carry up to several hundred people on a single train, and transport passengers between a limited number of stations. Each train draws up to several megawatts of electricity from an overhead catenary wire system; and the train&#39;s electrically-conductive metal wheels permit the underlying rails to act as a ground source, eliminating any need for a separate ground or return wire in the catenary wire system. Also, the high transmission voltages result in a relatively low current through the catenary wires. Thus, the catenary wires can have a relatively small cross-sectional area without sacrificing transmission efficiency, which in turn helps to minimize the cost of the wires. Also, the catenary wires are positioned above the train and well above the ground, keeping the wires out of the normal reach of pedestrians. An electrified roadway system for automobiles, by contrast, would need to supply relatively small amounts of electricity to thousands or tens of thousands of vehicles at the same time, with most of the vehicles traveling to different destinations; with the power-supplying means being located in proximity to the driver, passengers, and pedestrians; and with the vehicles being electrically-isolated from the ground by their non-conductive rubber tires. 
     SUMMARY 
     The present disclosure relates generally to electrified roadway systems and electric vehicles configured to operate on the roadway systems. In one aspect, the disclosed technology relates to electrified roadway systems having a roadway. The roadway includes a base, an electrically-conductive first rail mounted on the base, and an electrically-conductive second rail mounted on the base. The first rail is configured to be electrically connected to a source of electric power, and the second rail is configured to be electrically connected to an electrical ground. 
     The roadway systems also include a vehicle having a plurality of non-electrically-conductive tires; and an electric motor mechanically connected to, and configured to rotate at least one of the tires to propel the vehicle along the roadway. The vehicle also has a first and a second electrical pickup each being electrically connected to the electric motor. The first and second electrical pickups are configured to contact the respective first and second rails when the vehicle is located on the roadway. The roadway systems further include a first and a second cover positioned on the respective first and second rails and forming contact surfaces between the first and the second rails and the respective first and second electrical pickups. 
     In another aspect of the disclosed technology, the first and second covers each include a center portion, a first and a second side portion connected to opposite sides of the center portion, and a first and a second clip connected to the respective first and second side portions. The first and second clips of the first cover are configured to securely engage the first rail, and the first and second clips of the second cover are configured to securely engage the second rail. 
     In another aspect of the disclosed technology, the first and the second rails each have a first and a second groove formed therein; the first and second clips of the first cover are configured to securely engage the first rail by way of the respective first and second grooves in the first rail; and the first and second clips of the second cover are configured to securely engage the second rail by way of the respective first and second grooves in the second rail. 
     In another aspect of the disclosed technology, the first and second clips of the first cover are configured to flex and generate a contact force between the first rail and the first and second clips of the first cover when the first cover is positioned on the first rail; and the first and second clips of the second cover are configured to flex and generate a contact force between the second rail and the first and second clips of the second cover when the second cover is positioned on the second rail. 
     In another aspect of the disclosed technology, the first and second clips of the first cover extend upwardly and inwardly when the first cover is not positioned on the first rail; and the first and second clips of the second cover extend upwardly and inwardly when the second cover is not positioned on the second rail. 
     In another aspect of the disclosed technology, the first and second rails each include an upper surface having a substantially convex shape; the center portion of the first cover is substantially planar when the first cover is not positioned on the first rail; the center portion of the first cover is configured to flex and conform to the shape of the upper surface of the first rail when the first cover is positioned on the first rail; the center portion of the second cover is substantially planar when the second cover is not positioned on the second rail; and the center portion of the second cover is configured to flex and conform to the shape of the upper surface of the second rail when the second cover is positioned on the second rail. 
     In another aspect of the disclosed technology, the flexing of the center portion and the first and second clips of the first cover generates a contact force between the first cover and the first rail; and the flexing of the center portion and the first and second clips of the second cover generates a contact force between the second cover and the second rail. 
     In another aspect of the disclosed technology, a substantial entirety of an inner surface of the center portion of the first cover contacts the upper surface of the first rail when the first cover is positioned on the first rail; and a substantial entirety of an inner surface of the center portion of the second cover contacts the upper surface of the second rail when the second cover is positioned on the second rail. In another aspect of the disclosed technology, the first and second rails each include an upper surface having a substantially planar shape; the center portion of the first cover is substantially concave when the first cover is not positioned on the first rail; the center portion of the first cover is configured to flex and conform to the shape of the upper surface of the first rail when the first cover is positioned on the first rail; the center portion of the second cover is substantially concave when the second cover is not positioned on the second rail; and the center portion of the second cover is configured to flex and conform to the shape of the upper surface of the second rail when the second cover is positioned on the second rail. 
     In another aspect of the disclosed technology, the flexing of the center portion and the first and second clips of the first cover generates a contact force between the first cover and the first rail; and the flexing of the center portion and the first and second clips of the second cover generates a contact force between the second cover and the second rail. 
     In another aspect of the disclosed technology, a substantial entirety of an inner surface of the center portion of the first cover contacts the upper surface of the first rail when the first cover is positioned on the first rail; and a substantial entirety of an inner surface of the center portion of the second cover contacts the upper surface of the second rail when the second cover is positioned on the second rail. In another aspect of the disclosed technology, the first and second side portions of the first cover adjoin the opposite sides of the center portion of the first cover; the first and second clips of the first cover adjoin the respective first and second side portions of the first cover; the first and second side portions of the second cover adjoin the opposite sides of the center portion of the second cover; and the first and second clips of the second cover adjoin the respective first and second side portions of the second cover. 
     In another aspect of the disclosed technology, the center portion, the first and second side portions, and the first and second clips of the first cover are unitarily formed; and the center portion, the first and second side portions, and the first and second clips of the second cover are unitarily formed. 
     In another aspect of the disclosed technology, the first and second rails are formed at least partially from aluminum. 
     In another aspect of the disclosed technology, the first and second covers are formed from stainless steel. 
     In another aspect of the disclosed technology, the first and second covers are formed from a first material; the first and second rails are formed a second material; and the first material has a hardness greater than a hardness of the second material. 
     In another aspect of the disclosed technology, the center portion of the first cover is configured to flex and conform to the shape of an upper surface of the first rail when the first cover is positioned on the first rail; and the center portion of the second cover is configured to flex and conform to the shape of an upper surface of the second rail when the second cover is positioned on the second rail. 
     In another aspect of the disclosed technology, a substantial entirety of an inner surface of the center portion of the first cover contacts the upper surface of the first rail when the first cover is positioned on the first rail; and a substantial entirety of an inner surface of the center portion of the second cover contacts the upper surface of the second rail when the second cover is positioned on the second rail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and constitute part of this specification, are illustrative of particular embodiments of the present disclosure and do not limit the scope of the present disclosure. The drawings are not to scale and are intended for use in conjunction with the explanations in the following detailed description. 
         FIG. 1  is a schematic illustration of an electrified roadway system, and tracked electric vehicles configured to operate on the roadway system. 
         FIG. 2  is a schematic illustration of a track section of the roadway system shown in  FIG. 1 . 
         FIG. 3  is a perspective view of a portion of the roadway system shown in  FIGS. 1 and 2 , depicting one of the tracked electric vehicles operating on the roadway system. 
         FIG. 4  is a side view of the tracked electric vehicle shown in  FIGS. 1 and 3 , operating on the roadway system shown in  FIGS. 1-3 . 
         FIG. 5  is a front view of the tracked electric vehicle shown in  FIGS. 1, 3, and 4 , operating on the roadway system shown in  FIGS. 1-4 . 
         FIG. 6  is a schematic illustration of various electrical components of the roadway system and the tracked electric vehicle shown in  FIGS. 1-5 . 
         FIG. 7  is a schematic illustration of an alternative embodiment of the roadway system shown in  FIGS. 1-6 . 
         FIG. 8  is a schematic illustration of another alternative embodiment of the roadway system shown in  FIGS. 1-6 . 
         FIG. 9A  is a side view of an electrical pickup of the tracked electric vehicle shown in  FIGS. 1 and 3-8 , depicting the electrical pickup in a deployed position. 
         FIG. 9B  is a side view of the electrical pickup shown in  FIG. 9A , depicting the electrical pickup in a retracted position. 
         FIG. 10  is a side view of the electrical pickup shown in  FIGS. 9A and 9B , depicting the electrical pickup retracting and extending to traverse a gap in a conductive rail of the roadway system shown in  FIGS. 1-6 . 
         FIG. 11  is a schematic view of an alternative embodiment of conductive rails of the roadway system shown in  FIGS. 1-6 . 
         FIG. 12  is a magnified view of the area designated “A” is  FIG. 11 . 
         FIG. 13  is a front view of an alternative embodiment of the track section shown in  FIG. 2 . 
         FIG. 14  is a perspective view of a conductive rail of the roadway system shown in  FIGS. 1-6 , and a protective cover configured to cover the upper surface of the rail. 
         FIGS. 14A and 14B  are front views of alternative embodiments of the conductive rail and cover shown in  FIG. 14 ; 
         FIGS. 14C and 14D  are front views of other alternative embodiments of the conductive rail and cover shown in  FIG. 14 ; 
         FIG. 15  is a front exploded view of another alternative embodiment of the conductive rail shown in  FIG. 14 , and a support for the rail. 
         FIG. 16  is a front view of another alternative embodiment of the roadway system shown in  FIGS. 1-6 , depicting roof-mounted electrical pickups on the tracked electric vehicle. 
         FIG. 17  is a front view of an alternative embodiment of the roof-mounted electrical pickups shown in  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION 
     The following discussion omits or only briefly describes conventional features of the disclosed technology that are apparent to those skilled in the art. It is noted that various embodiments are described in detail with reference to the drawings, in which like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the claims appended hereto. Additionally, any examples set forth in this specification are intended to be non-limiting and merely set forth some of the many possible embodiments for the appended claims. Further, particular features described herein can be used in combination with other described features in each of the various possible combinations and permutations. 
     a. Introduction 
     A tracked electric vehicle system  10  is disclosed. The system  10  comprises an electrified highway, or tracked electric vehicle (TEV) track  12 , made up of sections of electrified track  14  as shown in  FIGS. 1-3 . The system  10  also includes electrically-powered vehicles  16  configured to operate on, and draw electrical power from the track  14 . Each vehicle  16  can be equipped with conventional air-filled, rubber-based automobile tires  108 , shown in  FIGS. 3-5 . The vehicle  16  also can have a steering mechanism  140 , brakes  142 , and an accelerator  144 , as depicted schematically in  FIG. 6 . The steering mechanism  140 , brakes  142 , and accelerator  144  can be operated both by the driver; and automatically, without driver input. Thus, the vehicle  16  does not require the use of rails or other mechanical provisions to guide the vehicle  16  along the TEV track  12 . The vehicle  16 , therefore, can operate off of, and independently of the TEV track  12 , on conventional public roads. 
     The vehicle  16  is configured to be controlled on a fully autonomous basis whenever the vehicle  16  is operating on the TEV track  12 . The position of the vehicle  16  in relation to the TEV track  12 , and in relation to other vehicles  16  operating on the TEV track  12 , is controlled via a central controller  18  of the system  10 , depicted schematically in  FIG. 6 . Thus, while it is anticipated that a driver will be present in the vehicle  16  during most, or all of the time the vehicle is operating on the TEV track  12 , the presence of a driver is not required once the controller  18  has assumed control of the vehicle  16 . 
     Multiple TEV tracks  12  can be installed in a parallel arrangement, with each of the individual TEV tracks  12  forming a lane of the system  10  as shown schematically in  FIG. 1 . In this particular embodiment, one TEV track  12  is dedicated to vehicular traffic traveling in one direction; and a second TEV track  12  accommodates vehicular traffic traveling in the other direction. 
     Alternative embodiments of the system  10  can include more than two TEV tracks  12 , to provide multiple lanes in each direction of traffic flow. For example,  FIG. 7  depicts a four-lane system  15  made up of two of the electrified TEV tracks  12  in each direction. Although the respective positions of all the vehicles  16  operating on the TEV tracks  12  can be controlled simultaneously by the central controller  18 , an added margin of safety can be achieved by placing conventional crash barriers (not shown) between adjacent TEV tracks  12 . 
     The system  15  can be configured to have having express and local tracks. The inner tracks can be designated express tracks  12   a , and can be used by vehicles  16  traveling at high speeds, such as 120 miles per hour (193 kilometers per hour). The outer tracks can be designated local tracks  12   b , and can accommodate vehicles  16  operating a lower speeds. Vehicles  16  can enter the express tracks  12   a  from the local tracks  12   b ; and the vehicles  16  can exit the express tracks  12   a  onto the local tracks  12   b.    
       FIG. 8  depicts another alternative embodiment in the form of a system  17 . The system  17  has a third, non-electrified TEV track  12   c  located between two of the electrified TEV tracks  12  described above in relation to the system  10 . The non-electrified, or inner TEV track  12   c  can be used as an alternative path of the travel for the vehicles  16  when sections of the outer, or electrified TEV tracks  12  are undergoing maintenance or otherwise are not available for vehicle traffic. The vehicles  16  can move onto the non-electrified TEV track  12   c , and can travel on the TEV track  12   c  under the vehicles&#39; own battery power when it is necessary to bypass a portion of one of the electrified TEV tracks  12 , thereby ensuring that vehicle traffic can remain flowing when one of the electrified TEV tracks  12  is not available. 
     Access to the TEV tracks  12  can be restricted by centrally-controlled gates  150  located at the various entrances  40  to the TEV tracks  12 . One of the gates  150  is depicted schematically in  FIG. 7 . 
     Thus, the TEV tracks  12  can be used at different times to accommodate traffic traveling in opposite directions. For example, a particular TEV track  12  can be used by vehicles  16  traveling toward a major city during morning commuting hours; and the same TEV track  12  can be used to accommodate vehicle traffic traveling away from the city during evening commuting hours. 
     The system  10 , and its various alternative embodiments, can be used to transport people and light freight, such as parcel freight. The vehicles  16  can be cars, small vans, and other vehicles configured to have relatively low aerodynamic resistance. These limitations help to minimize the energy requirements of the system  10 . Alternative embodiments of the system  10  can be configured to accommodate larger vehicles such as semi-trailer trucks, tall delivery vans, etc. Because the vehicles  16  are non-polluting electric vehicles, the vehicles  16  do not contribute to carbon dioxide production and global warming when the electricity consumed by the vehicles  16  is generated from a green, or non-polluting source. 
     Because the vehicles  16  do not stop on the TEV track  12 , the TEV track  12  can accommodate a continuous flow of vehicles  16 . Also, the TEV track  12  can be configured with many exits and entrances  40  to permit a high degree of flexibility in the locations at which the vehicles  16  can enter and exit the TEV track  12 . In a typical high-speed rail system, by contrast, trains must stop for at least several minutes at the stations along their routes, which can limit the capacity of the system to twelve trains or less per hour in each direction; also, the limited number of stations give passengers relatively limited options for the locations at which they can embark and disembark. Also, while high-speed trains may boast a top speed of 180 miles per hour (290 kilometers per hour), the average speed of such trains typically is about 124 miles per hour (200 kilometers per hour) or less. By contrast, because it is anticipated that vehicle traffic on the TEV track  12  can remain moving at all times at speeds of about 120 miles per hour (193 kilometers per hour), it is believed that a typical TEV track  12  can have ten or more times the passenger-carrying capacity per track or lane than a high-speed train. 
     b. Vehicle 
     Each vehicle  16  can include an electric drive motor  100 , a battery  102 , and a power regulator  104  electrically connected to the drive motor  100  and the battery  102 , as depicted schematically in  FIG. 6 . The battery  102  provides electrical power to the drive motor  100  on a selective basis, as discussed below. The drive motor  100  is configured to operate on direct current. In alternative embodiments in which the TEV track  12  is electrified by alternating current, the drive motor  100  can be an alternating current motor; or the drive motor  100  can be a direct current motor and the vehicle  16  can be equipped with a transformer-rectifier unit to transform the alternating current from the TEV track  12  into direct current. 
     Because the battery  102  is a secondary power source that is used primarily when the vehicle  16  is being operated on conventional roads; and because the battery  102  can be recharged when the vehicle  16  is operating on the TEV track  12 , the battery  102  can be smaller, lighter, and less expensive; and can have a longer service life than the battery of a conventional electric car. Alternative embodiments of the vehicle  16  can include more than one drive motor  100  and more than one battery  102 . 
     Referring to  FIG. 6 , the vehicle  16  also includes a control unit  112 , and a transceiver  114  communicatively coupled to the control unit  112 . The transceiver  114  communicates wirelessly with a transceiver  33  associated with the central controller  18 , via RF signals or other suitable means. The control unit  112  and the controller  18  thus communicate via the transceiver  114  and the transceiver  33 . In alternative embodiments, the control unit  112  and the central controller  18  can communicate via a wired connection routed, for example, through or along-side the TEV track  12 . 
     The control unit  112  comprises a processor, such as a microprocessor; a memory device communicatively coupled to the processor via an internal bus; and computer-executable instructions stored on the memory device and executable by the processor. The control unit  112  also comprises an input-output bus, and an input-output interface communicatively coupled to the processor by way of the input-output bus. The computer-executable instructions are configured so that the computer-executable instructions, when executed by the processor, cause the control unit  112  to carry out the various logical functions described herein. The above details of the control unit  112  are presented for illustrative purposes only. The control unit  112  can have components in addition to those described above, and can have an internal architecture other than that descried above. 
     The control unit  112  is communicatively coupled to, and can control the operation of the steering mechanism  140 , brakes  142 , and accelerator  144  of the vehicle  16 . The vehicle  16  can be operated manually, by the driver; or automatically, without driver input, as discussed below. 
     The control unit  112  can control the operation of the vehicle  16  on both a partially-autonomous basis, and a fully-autonomous basis. When operating on a partially-autonomous basis, the control unit  112  can control the direction of travel, speed, and braking of the vehicle  16 ; overall control of vehicle navigation, including turning onto different streets, entering and exiting highways, changing lanes, etc., remains with the driver. The partially-autonomous mode of operation can be used during operation of the vehicle  16  off the TEV track  12 . Alternatively, the vehicle  16  can be controlled exclusively by the driver when the vehicle  16  is being operated off the TEV track  12 . 
     When operating on a fully-autonomous basis, the control unit  112 , in conjunction with the central controller  18  of the system  10 , exercises full control of the position, steering, braking, speed, and navigation of the vehicle  16  via control of the steering mechanism  140 , brakes  142 , and accelerator  144 . This mode of operation is used only when, and whenever the vehicle  16  is being operated on the TEV track  12 . Fully autonomous control is feasible under these conditions because the central controller  18  knows the locations, speeds, directions of travel, and destinations of the vehicle  16 , and all the other vehicles  16  operating on the TEV track  12 . The central controller  18  thus can exercise simultaneous control over all of the vehicles  16  through the respective control units  112  of each vehicle  16 . The location, speed, and direction of travel of the vehicle  16  can be sensed by a GPS navigation device, or other suitable means, on the vehicle  16 ; and can be transmitted to the central controller  18  by way of the transceiver  114  and the transceiver  33 . Alternatively, or in addition, the TEV track  12  can be equipped with sensors (not shown) that detect the location, speed, and direction of travel of each vehicle  16 , and relay that information to the central controller  18 . 
     Each of the vehicles  16  can be assigned a unique identifier that is transmitted to the central controller  18 , and is used by the controller  18  to track and guide each individual vehicle  16 . The identifier also can be used for billing-related purposes such as monitoring the amount of energy used by a particular vehicle  16 ; and tracking the movement of the vehicle  16  to assess any tolls that may be due. 
     Each vehicle  16  includes two retractable electrical pickups  116 , depicted in  FIGS. 4, 5, 9A, 9B, 10, and 12 . The electrical pickups  116  conduct electric power between the TEV track  12  and the vehicle  16 . The electrical pickups  116  are mounted on an underside  21  of the vehicle  16 , in an orientation reversed, i.e., upside down, in relation to the normal orientation of a pantograph on a high-speed train. Each electrical pickup  116  can move between a lowered, or deployed position as shown in  FIGS. 4, 5, 9A, 9B, and 12 ; and a retracted, or stowed position shown in  FIG. 9B . 
     Each electrical pickup  116  includes an arm  117 , and a brush  118 . A first end of the arm  117  is connected to a rotatable coupling  119 . The coupling  119  is mounted on the underside  21  of the vehicle  16 , so that the arm  117  can rotate in relation to the underside  21  as shown in  FIGS. 9A and 9B . The coupling  119  is electrically insulated from its mounting surface. The arm  117  is formed from a rigid, electrically-conductive material such as aluminum. The arm  117  is electrically connected to the power regulator  104  of the vehicle  16  by way of a cable (not shown) or other suitable means. An actuator  120 , shown schematically in  FIG. 6 , is coupled the arm  117 , and provides the force needed to move the arm  117 . 
     The brush  118  is secured to a second end of the arm  117 , and extends in a direction substantially perpendicular to the longitudinal axis of the arm  117 . Each brush  118  contacts an upper surface of an electrically conductive first or second rail  30 ,  32  of the TEV track  12 , when the electrical pickups  116  are in their deployed position. The brushes  118  are elongated, as shown in  FIG. 5 ; and are oriented to extend in a direction substantially perpendicular to the first or second rail  30 ,  32  when the vehicle  16  is traveling on the TEV track  12 , so that the brushes  118  can maintain contact with the first or second rails  30 ,  32  as the vehicle  16  drifts from side to side during normal travel. 
     The brushes  118  can be formed from carbon; the brushes  118  can be formed from other electrically-conductive materials in the alternative. Each brush  118  is electrically connected to the power regulator  104  of the vehicle  16  by way of its associated arm  117 , and the cable that electrically connects the arm  117  to the power regulator  104 . The electrical pickups  116 , when in their deployed position, establish electrical contact between the vehicle  16  and the first and second rails  30 ,  32 , and thereby permit electric current to flow between the vehicle  16  and the TEV track  12 . As can be seen in  FIG. 9B , when in the retracted position, the electrical pickups  116  are located out of close proximity to the TEV track  12  and the ground, thereby permitting the vehicle  16  to operate on conventional roadways without interference between the electrical pickups  116  and the roadway. 
     The actuators  120  can be communicatively coupled to, and controlled by the control unit  112  of the vehicle  16 , so that the control unit  112  can command the extension and retraction of the electrical pickups  116 . The commands can be generated by the control unit  112  automatically, or in response to inputs from the driver. For example, as discussed below, the control unit  112  can automatically command the extension and retraction of the electrical pickups  116  to cause the electrical pickups  116  to “jump” over a damaged portion of the first or second rails  30 ,  32 ; or to jump over a gap between the first or second rails  30 ,  32  of adjacent track sections  30 ,  32 , as depicted in  FIG. 10 . 
     The electrical pickups  116  can be configured to extend in a consistent, predetermined manner. For example, the control unit  112  can be configured to command the actuator  120  to undergo its full deflection during extension of the electrical pickup  116 . Alternatively, a force sensor (not shown) can be mounted on the arm  117  or the actuator  120 , and can be communicatively coupled to the control unit  112 . The control unit  112  can use the reading from the force sensor to continuously control the position of the actuator  120  so as to cause the brush  118  to contact the first or second rail  30 ,  32  with a consistent force sufficient to ensure adequate power transfer to the vehicle  16 , but low enough to avoid excessive wear of the brush  118  and/or the first or second rail  30 ,  32 . 
     In alternative embodiments, shoes or other suitable contacting means for transferring power between the vehicle  16  and the first and second rails  30 ,  32  can be used in lieu of the brushes  118 . Also, the actuator  120  can be further configured to cause the electrical pickups  116  to slowly oscillate side to side, i.e., in a direction substantially perpendicular to the first and second rails  30 ,  32 , when the electrical pickups  116  are in their deployed position, to help equalize wear on the brushes  118 . The above-noted configuration of the electrical pickups  116  is disclosed for illustrative purposes only; the electrical pickups  116  can have other configurations in alternative embodiments. 
     The maximum power consumption of the vehicle  16 , when powered by direct current as described herein, is estimated to be about 40 kiloWatts (kW) when the vehicle  16  is traveling at 120 miles per hour (193 kilometers per hour). It is believed that this amount of power can be transferred by a brush  118  having an overall contact area of only about 0.9 square inches (about six square centimeters). This relatively low level of required power transfer is a result of the decentralized power management inherent in the use of relatively small, stand-alone vehicles each propelled by its own drive motor  100 . High-speed trains, by contrast, typify centralized power management in a transportation vehicle. The peak power transfer to a high-speed train can be as high as several megawatts, which necessitates a larger and more complex power-transfer interface and power management system than that required by the vehicle  16 . 
     The system  10  can be equipped with security measures to enhance the safety, security, and confidence of drivers and passengers. Because the system  10  and the vehicles  16  are centrally controlled, it is believed that such security measures can be implemented with relative ease, with little or no inconvenience to drivers and passengers, and with minimal added expense. 
     For example, the vehicles  16  can be equipped with a facial recognition system that ties the vehicle  16  to its owner or to a pre-approved driver, thereby reducing the risk that stolen vehicles  16  will be driven onto the system  10 . Also, drivers of rented vehicles  16  can be made to undergo a security check at the rental counter, before the driver is given access to the vehicle  16 . The check can include taking photographs of the driver; and obtaining approval for the driver from a data base to verify, for example, that the driver is licensed and is not subject to any outstanding warrants. Also, the system  10  can be configured to initiate a telephone call directly to the driver. The call can be made by a machine or a human, and the driver can be asked a salient question about his or her trip to help verify that that the driver intends to use the roadway system  10  for a legitimate, legal purpose. Also, rental vehicles  16  and other vehicles not being operated by or on behalf by the owner can be equipped with a sniffer located, for example, in the trunk of the vehicle  16 , to detect contraband or explosives. Other types of security checks can be evolved over time. 
     c. TEV Track 
     Each TEV track  12  preferably is constructed on a modular basis, from individual sections of electrified track  14 . Referring to  FIGS. 2 and 5 , each track section  14  includes an elongated base  29 , the first electrically-conductive rail  30 , and the second electrically-conductive rail  32 . The track sections  14  are arranged end to end to form a single lane or TEV track  12 . The track sections  14  preferably are manufactured as modules; and can be assembled in the field by attaching adjacent track sections  14  to each other, and to the ground, using conventional techniques known in the road-construction industry. 
     The base  29  can be formed from a durable, high-strength, relatively low cost material. For example, each base  29  can be made from concrete covered with tarmac. Alternatively, the base  29  can be formed from sheet steel strips coated with tungsten carbide grit. The strips can be cut at a slant in 50-foot (15-meter) sections, and can be bolted down onto suitable anchors. The strips can be replaced when worn by automated pick and place machines. The base  29  can be formed from other materials in the alternative. 
     The first and second rails  30 ,  32  are mounted on the base  29 , as discussed in detail below. The first and second rails  30 ,  32  are elongated rails each having a substantially rectangular cross section. The first and second rails  30 ,  32  can have other types of cross sections, and other overall configurations in alternative embodiments. The first rail  30  provides electric power to the vehicle  16 , while the second rail  32  provides a return path, or ground, for the electric current. This two-conductor arrangement is necessary because the vehicle  16  has rubber-based tires  108  that, in contrast to the metal wheels of an electrically-powered train, do not provide a return path for the electric current supplied to the vehicle  16 . In alternative embodiments, the second rail  32  can provide electric power to the vehicle  16 , while the first rail  30  acts as a ground. 
     As can be seen in  FIG. 5 , the first and second rails  30 ,  32  are located beneath the vehicle  16  when the vehicle  16  is traveling on the TEV track  12 . In alternative embodiments, the first rail  30  and the second rail  32  can be positioned in other locations in relation to the vehicle  16 . For example, the first and second rails  30 ,  32  can be positioned in a wall-mounted configuration in which the first and second rails  30 ,  32  are located to the side of the vehicle  16 . 
     The first and second rails  30 ,  32  each can have a length of about 2,460 feet (about 750 meters). The first and second rails  30 ,  32  can have a length that is greater, or less than this value. Longer-length rails, in general, will have a lower cost per unit length than comparable shorter rails, but the longer length can make the rails difficult to transport, store, and handle. Also, longer-length rails may need to be formed from a more expensive higher-conductivity material than shorter rails, to offset the greater resistive losses associated with transmitting electricity over the increased length of the longer rails. 
     Referring to  FIG. 3 , each track section  14  can include an enclosure or housing  200  that spans the entire length of the track section  14 . The housing  200  has two side panels  202  mounted on opposite sides of the base  29 ; and a roof panel  204  mounted on, and supported by the side panels  202 . The roof panel  204  can be solid, and inhibits rain, snow, leaves, and other foreign objects from falling onto the roadway surface. The side panels  202  can be formed as a series of rails that inhibit pedestrians, animals, and unauthorized vehicles from entering the roadway, while providing drivers and passengers with a view outside of the housing  200 . Restricting access to the roadway and sheltering the roadway from the elements can enhance safety, and can permit the vehicles  116  to travel at faster speeds than otherwise would be possible. The roof panel  204  and the side panels  202  can have other configurations in alternative embodiments. For example, the side panels  202  can be solid in alternative embodiments. In other embodiments, the roof panel  204  and the side panels  202  can be formed as a unitary tubular structure. Also, solar panels can be installed on the roof panel  204  and/or the side panels  202 , to help power the system  10 . For clarity of illustration, the roof panel  204  and side panels  202  are shown in  FIG. 3  only. 
     Referring to  FIGS. 2 and 5 , the base  29  of each track section  14  has an upper surface  210 . The upper surface  210  includes a middle portion  208 , and two outer portions  212  that each adjoin the middle portion  208 . The middle portion  208  is elevated in relation to the outer portions  212 , as can be seen in  FIG. 5 . The upper surface  210  can have other configurations in alternative embodiments. 
     The first and second rails  30 ,  32  are mounted in respective supports  206 . The supports  206  are secured to the middle portion  208  of the upper surface  210  of the base  29 , by a suitable means such as fasteners (not shown). The supports  206  can be formed from a high-strength material, such as steel, coated with an electrically-insulating material. The supports  206  can have a U-shaped cross section, as shown in  FIG. 5 , so that the first and second rails  30 ,  32  are accessible, or open, from above. The supports  206  can have other shapes, and can be formed from other materials, in the alternative. 
     Electrically-insulating barriers or strips (not shown) can be positioned adjacent the first and second rails  30 ,  32 , to reduce the potential for accidental human contact. 
     The first and second rails  30 ,  32  are restrained from vertical movement in relation to their associated support  206  by their own weight, and by friction between the contacting vertical surfaces of the support  206  and the first and second rails  30 ,  32 . In alternative embodiments, the supports  206  can be equipped with provisions to restrain the first and second rails  30 ,  32  vertically, while permitting the first and second rails  30 ,  32  to move longitudinally, i.e., in the lengthwise direction, to accommodate thermally-induced expansion of the first and second rails  30 ,  32  in relation to the supports  206 . Such restraint can be provided, for example, by bolts (not shown) that span width of the supports  206 . The bolts can extend through circular holes in opposite sides of the supports  206 , and through longitudinally-oriented slots in the first and second rails  30 ,  32 . The orientation of the slots permits the first and second rails  30 ,  32  to move longitudinally in relation to the bolt and the support  206 , while the bolt and the support  206  prevent substantial movement of the first or second rail  30 ,  32  in the vertical direction. 
     The middle portion  208  of the upper surface  210  of the base  29  has provisions that promote the drainage of the middle portion  208 , to prevent accumulation of water and other liquids around the first and second rails  30 ,  32 . These provisions can take the form of, for example, channels or drain holes (not shown). 
     Each track section  14  also includes two friction strips  211 . The friction strips  211  are secured to the respective outer portions  212  of the upper surface  210  of the base  29 , and shown in  FIGS. 2 and 5 . The friction strips  211  form the surfaces of the TEV track  12  that contact the tires  108  of the vehicles  16 , and can be formed from a durable, wear-resistant material having a relatively high coefficient of friction. 
     The first and second rails  30 ,  32  can be mounted in other ways in alternative embodiments. For example,  FIG. 13  depicts an alternative embodiment in which first and second rails  30   a ,  32   a  are mounted in respective longitudinal slots or channels  36  formed in a base  29   a , using a suitable means such as brackets or fasteners. The channels  36  can be sized so that an upper surface of each of the first and second rails  30   a ,  32   a  is positioned higher than an upper surface  38  of the base  29   a , by an amount sufficient to permit reliable contact between the upper surfaces of the first and second rails  30   a ,  32   a , and the brushes  118  of the vehicle  16 . The space between each of the first and second rails  30 ,  32  and the adjacent surfaces of the base  29  can be filled with an electrically-insulating material  45 . 
     In other alternative embodiments (not shown), the first and second rails  30 ,  32  can be mounted on insulators that are secured to, and positioned above the upper surface  210  of the base  29 . This non-recessed mounting arrangement can help to reduce stray electrical currents under wet conditions. 
     The first and second rails  30 ,  32  can be formed from an electrically-conductive material such as copper, aluminum, steel, etc. While aluminum is less expensive than copper and steel, aluminum is less resistant to the normal wear that can result from the movement of the brushes  118  over the first and second rails  30 ,  32 . The rate of such wear may be acceptable due the relatively low contact forces between the brushes  118  and the first and second rails  30 ,  32  in comparison to the contact forces exerted by, for example, a typical electrical pickup on a high-speed train. If it is necessary or otherwise desirable to reduce the wear rate on the first and second rails  30 ,  32 , however, such reductions can be achieved, for example, by coating the upper, or contact surfaces of the first and second rails  30 ,  32  with a relatively hard, wear-resistant material such as stainless steel; by installing a protective covering, formed from a relatively hard, wear-resistant material, on the contact surfaces; or by forming the first and second rails  30 ,  32  from an aluminum alloy with greater wear resistance than pure aluminum. For example,  FIG. 14  depicts a self-locking stainless steel cover  213  that can be installed on the first and second rails  30 ,  32  to protect the underlying aluminum from wear. 
     It is believed that the cost of the first and second rails  30 ,  32 , when formed from aluminum with a stainless-steel coating or covering, will be less than half the cost of comparable conductors formed from steel or copper. Also, aluminum is readily available, and can be formed into desired shapes through a relatively simple extrusion process that can be performed in most countries throughout the world. Also, the use of aluminum allows the first and second rail  30 ,  32  to be recycled upon reaching the end of their service life. 
     Each of the first and second rails  30 ,  32  can be formed as a single piece, as depicted, for example, in  FIG. 14 .  FIGS. 5 and 15  depict an alternative embodiment of the first and second rails  30 ,  32  in the form of first and second rails  30   b ,  32   b . The first and second rails  30   b ,  32   b  have a modular construction. In particular, the first and second rails  30   b ,  32   b  are each formed from three separate electrically-conductive elements. A first and a second of the elements, designated  33   a  and  33   b  respectively, have a vertical dimension, or height, that is less than the height of the third element, designated  33   c . The third element  33   c  is depicted in  FIGS. 5 and 15  as being positioned between the first and second elements  33   a ,  33   b . The third element  33   c  can be positioned to the right, or left of both of the first and second elements  33   a ,  33   b  in the alternative. The first, second, and third elements  33   a ,  33   b ,  33   c  are secured to each other by a suitable means such as bolts or other types of fasteners (a bolt suitable for this purpose is depicted in  FIGS. 14A-14D ). 
       FIGS. 14A and 14B  depict alternative embodiments of the third element  33   c  and the stainless steel cover  213  in the form of, respectively, an electrically-conductive element  33   d  and a stainless steel cover  320 . The cover  320  comprises a top portion  322 , two side portions  324  that adjoin opposite sides of the top portion  322 , and two clips  326 . Each clip  326  adjoins a respective one of the side portions  324 , and extends inwardly and upwardly from the side portion  324  when the cover  213  is not positioned on the electrically-conductive element  33   d , as can be seen in  FIG. 14B . The top portion  322 , side portions  324 , and clips  326  are unitarily formed. The top portion  322 , side portions  324 , and clips  326  can be formed separately, and can be connected by a suitable means such as welding in alternative embodiments. 
     The electrically-conductive element  33   d  has two longitudinally-extending detents, or grooves  328  formed therein, on opposite sides of the element  33   d . Each groove  328  receives a respective one of the clips  326  of the cover  320 . The clips  326  flex and snap into their respective grooves  328  during assembly and securely engage the element  33   d , as shown in  FIG. 14B , so that interference between the clips  326  and the element  33   d  retains the cover  320  on the element  33   d . The center portion  322  forms the contact area between the cover  320  and the brushes  118  of the vehicle  16 . 
     The upper surface of the electrically-conductive element  33   d  has an outwardly curved, or convex shape, as shown in  FIGS. 14A and 14B . The cover  320  is configured so that the center portion  322  is substantially planar when the cover  320  is not installed on the element  33   d , as shown in  FIG. 14A . Also, the cover  320  is thin enough to permit the center portion  322  to flex and conform to the shape of the upper surface of the element  33   d  when the cover  320  is installed on the element  33   d , as can be seen in  FIG. 14B . The flexing of the center portion  322  and the clips  326  causes the cover  320  and the clips  326  to generate a spring force that helps to maintain secure contact between the clips  326  and the element  33   d ; and between the center portion  322  of the cover  320  and the upper surface of the element  33   d . Also, the conformance of the center portion  322  to the shape of the upper surface of the element  33   d  causes a substantial entirety of an inner surface of the center portion  322  to contact the upper surface of the element  33   d . This maximal contact maximizes the contact area between the center portion  322  and the upper surface of the element  33   d , which in turn helps to maximize electrical conductivity between the element  33   d  and the cover  320 . Electrical contact between the cover  320  and the element  33   d  can be further enhanced by the use of an electrically conductive cement between the cover  320  and the element  33   d.    
       FIGS. 14C and 14D  depict an alternative embodiment of the cover  320  in the form of a stainless-steel cover  330 . The cover  330  is adapted for use with an electrically conductive element  33   e  having a substantially planar upper surface. The cover  330  comprises a top portion  332 . The cover  330  also includes two of the side portions  324 , and two of the clips  326  described above in relation to the cover  320 . The side portions  324  adjoin opposite sides of the top portion  332 . Each clip  326  adjoins a respective one of the side portions  324 . The clips  326  flex and securely engage grooves  328  formed in the element  33   e  when the cover  330  is installed on the element  33   e , as can be seen in  FIG. 14D . The top portion  332 , side portions  324 , and clips  326  are unitarily formed. The top portion  332 , side portions  324 , and clips  326  can be formed separately, and can be connected by a suitable means such as welding in alternative embodiments. 
     The top portion  332  has an inwardly curved, or concave shape when the cover  330  is not installed on the element  33   e , as shown in  FIG. 14C . The cover  330  is thin enough to permit the center portion  332  to flex and conform to the planar shape of the upper surface of the element  33   e  when the cover  330  is installed on the element  33   e , as can be seen in  FIG. 14D . As discussed above in relation to the cover  320 , the flexing of the center portion  332  and the clips  326  helps to maintain secure contact between the clips  326  and the element  33   e , and between the center portion  332  and the upper surface of the element  33   e ; and maximizes the contact area between the center portion  332  and the upper surface of the element  33   e.    
     The self-conforming covers  320 ,  330  can be particularly advantageous in applications, such as the system  10 , in which the external force exerted on the covers  320 ,  330  is relatively light. In the system  10 , the light contact force exerted by the brushes  118  does not substantially increase the contact area or the electrical conductivity between the covers  320 ,  330  and the underlying electrically-conductive elements  33   d ,  33   e . By contrast, trains that draw power from an electrified rail often draw power through a single large shoe that contacts the electrified rail with a substantial contact force. In applications where a stainless-steel wear cover is used to cover the electrified rail, the substantial contact force exerted by the shoe can be sufficient to maintain satisfactory mechanical and electrical contact between the cover and the underlying rail. In the system  10 , by contrast, the relatively light contact force exerted by the brushes  118  of each individual vehicle  16  is too small to reliably deflect a stainless steel cover. The covers  320 ,  330  address this potential issue by self-generating a substantial contact force between the covers  320 ,  330  and the respective electrically-conductive elements  33   d ,  33   e . The covers  320 ,  330  thus can permit the use of aluminum rails without the wear-related issues normally associated with such rails, and without the electrical-conductivity issues that can result from the use of a stainless-steel wear cover in a light duty, i.e., low-contact-force, application. 
     The covers  320 ,  330  are described in connection with a three-element modular conductor for illustrative purposes only. The covers  320 ,  330  can be used in connection with single-piece conductors; and with modular conductors having less, or more than three electrically-conductive elements. Also, the covers  320 ,  330  can be formed from relatively hard, wear-resistant materials other than stainless steel. 
     The support  206  defines a space, or volume  207  that accommodates the elements  33   a ,  33   b ,  33   c  (or  33   d ) of the first and second rails  30   b ,  32   b . The volume  207  has a width that is approximately equal to the combined width of the first, second, and third elements  33   a ,  33   b ,  33   c , so that the first, second, and third elements  33   a ,  33   b ,  33   c  are restrained from substantial lateral, or side-to-side movement, in relation to the support  206 . 
     The elements  33   a ,  33   b ,  33   c  are restrained by the support  206  in the longitudinal, or lengthwise direction by an amount sufficient to permit the elements  33   a ,  33   b ,  33   c  to resist longitudinal movement in response to friction with the brushes  118  of the electrical pickups  116 , while allowing the elements  33   a ,  33   b ,  33   c  to expand and contract in the longitudinal direction in response to changes in temperature. The longitudinal restraint of the first and second rails  30   b ,  32   b  can be provided, for example, by friction between the contacting surfaces of the support  206  and the first and second rails  30   b ,  32   b . If necessary, excessive movement of the first and second rails  30   b ,  32   b  in the longitudinal direction can be prevented by the optional bolts that engage the supports  206 , and the horizontally-oriented slots in the first and second rails  30   b ,  32   b  as discussed above. 
     If necessary, the supports  206  and the first and second rails  30   b ,  32   b  can be equipped with friction-reducing features that facilitate longitudinal deflection of the first and second rails  30   b ,  32   b , to help ensure that the first and second rails  30   b ,  32   b  can expand and contract in response to changes in temperature. For example, the first and second rails  30   b ,  32   b  can rest on rollers; and/or an anti-friction coating can be applied to the contacting surfaces of the supports  206  and the first and second rails  30   b ,  32   b.    
     Because the third element  33   c  has a greater height than the first and second elements  33   a ,  33   b , the electrical pickups  116  contact the first and second rails  30 ,  32  exclusively by way of the third elements  33   c , as can be seen in  FIG. 5 . The first and second elements  33   a ,  33   b , therefore, do not need to be equipped with a wear-resistant coating or cover. Thus, the areas of contact on the first and second rails  30   b ,  32   b , and the expense of coating or covering those areas, are minimized; while the combined cross-sectional area of the first and second rails  30   b ,  32   b  can remain large enough to permit the first and second rails  30   b ,  32   b  to conduct relatively large amounts of electric power without overheating. The use of three conductive elements  33   a ,  33   b ,  33   c  is disclosed for illustrative purposes only; the number of conductive elements in each of the first and second rails  30   b ,  32   b  can be varied to accommodate the maximum rated current for the first and second rails  30   b ,  32   b  in a particular application. Also, the multiple conductive elements can have equal heights in alternative embodiments. 
     Because the current-carrying capacity of the first and second rails  30   b ,  32   b  is related to the number of individual conductive elements within each of the first and second rails  30   b ,  32   b , the current-carrying capacity can be tailored to the requirements for a particular section of the TEV track  12  by varying the number of conductive elements. For example, a greater number of conductive elements can be used on uphill sections of the TEV track  12 , where the power requirements of the vehicles  16  are relatively high. Conversely, a lesser number of conductive elements, or no conductive elements at all, can be used on downhill sections, where power requirements are lower. The ability to tailor the current-carrying capacity of the first and second rails  30   b ,  32   b  in this manner can help avoid the unnecessary expenditure of capital resulting from equipping portions of the TEV track  12  with greater current-carrying capacity than necessary. 
     Also, this modular configuration for the first and second rails  30   b ,  32   b  can facilitate expansion of the TEV track  12  to accommodate increases in traffic volume over time. For example, the first and second rails  30   b ,  32   b  each can be equipped with only one conductive element when the system  10  initially is brought on line and the traffic volume is expected to be relatively low. Additional elements can be added as the traffic volume, and the associated power requirements, increase over time. For example, an initial increase in traffic can be accommodated by adding a second conductive element. If the conductive elements are two inches (five centimeters) wide by four inches (ten centimeters) tall, the addition of the second conductive element would increase the respective cross sectional areas of the first and second rails  30   b ,  32   b  from eight square inches to 16 square inches (103 square centimeters), and would double the currently-carrying capability of the first and second rails  30   b ,  32   b . Further increases in traffic could be accommodated by adding a third conductive element, increasing the cross sectional areas of the first and second rails  30   b ,  32   b  to 24 square inches (155 square centimeters). The relatively wide, unobstructed area beneath the vehicle  16  can facilitate the installation of additional conductive elements to accommodate further increases in traffic volume. 
     Thus, the initial capital expenditure for the system  10  can be tailored to the anticipated initial traffic volume, instead of requiring an initial outlay of capital for traffic capacity that may not be needed until well into the future, if ever. Also, vehicles powered by internal combustion engines can be allowed to operate on the system  10  during its initial period of operation; and the revenue collected from the operators of such vehicles can be used to finance expansion of the system  10 . 
     As can be seen in  FIG. 5 , the underside  21  of the vehicle  16  is smooth and unobstructed, and the relatively large area between the vehicle&#39;s tires  108  can accommodate substantial expansion of the first and second rails  30   b ,  32   b . In such an expandable roadway, wider supports  206  can be installed when additional conductive elements are added. Alternatively, supports  206  wide enough to accommodate additional conductive elements can be installed initially; and inexpensive, non-conductive spacers or other means can be placed in the volume  207  to fill out the volume  207  in the lateral direction, and to support and secure the single conductive element in place until additional conductive elements are added. 
     Also, the relative flexibility of the thin conductive elements  33   a ,  33   b ,  33   c  allows the conductive elements to be bent into shallow curvilinear shapes by hand, or with simple tooling. Curved sections of the TEV track  12  can be formed, for example, by placing one of the conductive elements  33   a ,  33   b ,  33   c , such as the third conductive element  33   c , on a curved base  29 ; shaping the third conductive element  33   c  into a desired shape; and then securing the third conductive element  33   c  in position on the base  29 . The first and second conductive elements  33   a ,  33   b  then can be secured to the third conductive element  33   c , and to the base  29 . The ability to easily form the first and second rails  30 ,  32  into curved shapes in this manner can help minimize the different types of conductive elements that that need to be procured, and maintained in inventory, as the roadway  10  is constructed. 
     Unlike the overhead catenary of an electrified rail system, the first and second rails  30 ,  32  (and their alternative embodiments) are supported from below along their entire length; and the surfaces that contact the electrical pickups  116  face upward. Thus, there is no need to tension the first and second rails  30 ,  32 , using large weights and pulleys or other measures, to prevent the first and second rails  30 ,  32  from sagging. Also, due to the positive lateral restraint provided by the supports  206 , the first and second rails  30 ,  32  do not move substantially in the lateral, i.e., side to side, direction; and can adhere very closely to the curvature of the roadway. In the TGV high-speed train system, by contrast, a 0.6 inch (15 millimeter) overhead copper power wire has two grooves so that it can be supported by clamps hung from a cantenary wire and drop wires located every few meters. The power wire requires this support to prevent it from sagging; thus, the power and cantenary wires always are under a powerful and controlled tension provided by large and unsightly weights and pulleys mounted on trackside poles. 
     Thermally-induced expansion and contraction of the first and second rails  30 ,  32  (and their alternative embodiments) can be accommodated by providing a gap  209  between the ends of the first rails  30  of adjacent track sections  14 ; and another gap  209  between the ends of the second rails  32  of the adjacent track sections  14 . The gaps  209  are depicted in  FIG. 10 . Each gap  209  can be, for example, about 80 inches (about two meters). A gap  209  of this magnitude may be necessary to accommodate the longitudinal deflection of the first and second rails  30 ,  32  that can result from changes in the ambient temperature; from internal heating of the first and second rails  30 ,  32  caused by the transmission of electric current; and from friction between the first and second rails  30 ,  32  and the brushes  118  of the first and second electrical pickups  116 . 
     The gap  209  can be achieved by sizing the first and second rails  30 ,  32  so that each end of the first and second rails  30 ,  32  is located about 40 inches (about one meter) from the adjacent end of its associated base  29 , as depicted in  FIG. 2 . The base  29  is not expected to undergo significant thermally-induced expansion and contraction because it will be under cover and not heated by the sun in most applications; and because the base  29  can be formed from materials, such as concrete covered in tarmac, that do not undergo substantial thermally-induced expansion and contraction. Thus, a substantial gap is not needed between the bases  29  of adjacent track section  14 ; and the surfaces of the TEV track  12  that contact the tires  108  of the vehicle  16  are substantially continuous along the length of the TEV track  12 . Also, the gaps  209  electrically isolate each first rail  30  from its adjacent first rails  30 ; and electrically isolate each second rail  32  from its adjacent second rails  32 . As discussed below, this feature can allow portions of the TEV track  12  to be de-energized, while other portions of the TEV track  12  remain energized and able to accommodate vehicle traffic. 
     The vehicle  16  can be configured so that the electrical pickups  116  are partially retracted, or raised, on a momentary basis, by an amount sufficient to prevent the brushes  118  from contacting the exposed ends of the first and second rails  30 ,  32  on either side of the gaps  209 . This feature can help to prevent damage to the brushes  118  that otherwise could occur when the brushes  118  contact the exposed ends of the first and second rails  30 ,  32 . The sequential raising and lowering of one of the electrical pickups  116  as the pickup  116  traverses the gap  209  is depicted in  FIG. 10 , with the path of the brushes  118  denoted by the dashed line. 
     The retraction and subsequent extension of the electrical pickups  116  can be controlled electronically, by the control unit  112  of the vehicle  16 . The control unit  112  can be provided with information regarding the positions of the gaps  209  by, for example, physical or electronic markers located at a predetermined distance from the gaps  209 . The vehicle  16  can be configured with suitable sensors (not shown) for sensing the presence of the markers. Upon sensing a marker, the control unit  112  can command the electrical pickups  116  to partially retract by, for example, about one-half inch (about 1.3 centimeters). The control unit  112  can command the electrical pickups  116  to return to their deployed positions once the electrical pickups  116  have traversed the gap  209 . The “deploy” logical command can be issued, for example, after a predetermined time interval; this interval can be adjusted, i.e., shortened or lengthened, based on the speed of the vehicle  16 , to help minimize the time over which the brushes  118  are out of contact with the first and second rails  30 ,  32 . For example, if one-tenth of a second is required to retract the electrical pickups  116  and another one-tenth of a second is required to re-deploy the electrical pickups  116 , and the vehicle  16  is traveling at 120 miles per hour (193 kilometers per hour), the vehicle  16  will travel at least 33 feet (10 meters) before contact is restored with the first and second rails  30 ,  32 . The on-board battery  102  of the vehicle  16  can prevent the motor  100  and other electrical components of the vehicle  16  from dropping off line during the momentary interruption of power to the vehicle  16  as the electrical pickups  116  traverse the gaps  209 . 
     The automatic retraction and extension of the electrical pickups  116  also can be applied to avoid contact between the electrical pickups  116  and damaged sections of the first and second rails  30 ,  32 . The control unit  112  can be configured to raise the electrical pickups  116  when a sensor (not shown) on the vehicle  16  detects damage to the first or second rail  30 ,  32 ; or when the vehicle  16  is notified by the central controller  18  of the location of such damage. The control unit  112  can be configured to automatically report the location of the damage to the central controller  18 , so that corrective action can be undertaken, and other vehicles  16  on the TEV track  12  can be notified of the location of the damage. Allowing the electrical pickups  116  to “jump” over damaged sections of the first and second rails  30 ,  32  in this manner can prevent damage or premature wear of the brushes  118 , and other portions of the electrical pickups  116 , that otherwise could result from contact with the damaged conductor sections. 
     In the alternative, the TEV track  12  and the electrical pickups  116  can be equipped with mechanical provisions (not shown) that: lift the electrical pickups  116  as the electrical pickups  116  approach a gap  209 ; maintain the electrical pickups  116  in a partially retracted position as the electrical pickups  116  traverse the gap  209 ; and return the electrical pickups  116  to their deployed positions after the electrical pickups  116  have traversed the gap  209 . 
       FIGS. 11 and 12  depict an alternative embodiment in which the gaps  209  are spanned by relatively short electrically-conductive rails  220 , so that there is no interruption in the power being supplied to the vehicle  16 . A first end of each short rail  220  is securely connected to one of the first or second rails  30 ,  32  by way of an electrically conductive coupling  213 . A second end of the short rail  220  is connected to the adjacent first or second rail  30 ,  32  by way of an electrically-insulating coupling  215 . The coupling  215  is configured to slide on the adjacent first or second rail  30 ,  32 , to facilitate relative movement between adjacent first rails  30 , and between adjacent second rails  32 . 
     As can be seen in  FIG. 11 , the end portions of the first and second rails  30 ,  32  attached to the electrically-insulating coupling  215  overlap their associated short rails  210  in the longitudinal direction, so that the brushes  118  of the electrical pickups  116  remain supplied with electric power at all times during which the electrical pickups  116  traverse the gaps  209 . In addition, this approach eliminates any need to retract the electrical pickups  116  as the pickups  116  traverse the gaps  209 . Also, because the coupling  215  is electrically insulating, each first rail  30  is electrically isolated from its adjacent first rails  30 ; and each second rail  32  is electrically isolated from its adjacent second rails  32 . 
     Because each of the first and second rails  30 ,  32  is electrically isolated from the first and second rails  30 ,  32  of adjacent track sections  14 , portions of the TEV track  12  can be de-energized on a selective basis, while other portions of the TEV track  12  remain powered and capable of accommodating vehicle traffic. The ability to de-energize sections of the TEV track  12  not being used can lead to cost savings resulting from decreased consumption of electricity. For example, during periods of low vehicle traffic, such as late night, the central controller  18 , which monitors the locations of every vehicle on the TEV track  12 , can automatically de-energize sections of the TEV track  12  on which no vehicles  16  are present, while maintaining power to portions of the TEV track  12  on which any vehicles  16  are traveling. The controller  18  can be configured to energize the track sections  14  on which any vehicles  16  are located, and the track section  14  immediately ahead of the vehicles  16 , to ensure that the vehicles  16  remain powered by the TEV track  12  at all times. A particular track section  14  can be energized and de-energized through commands, issued by the central controller  18  to an individual electrical sub-station  310  associated with that track section  14 , to cut-off or restore power to the first rail  30  of the track section  14 . 
     The ability to de-energize select portions of the TEV track  12  also can be used, for example, to de-energize sections  14  of the TEV track  12  on which a stopped vehicle  16 , or a vehicle  16  with an open passenger door, window, or other exterior access point is located; damaged sections  14  of the TEV track  12 ; and sections  14  of the TEV track  12  undergoing maintenance. 
     The vehicles  16  can be configured so that the exterior access points of the vehicles  16  normally are locked in their closed positions when the vehicles  16  are located on the TEV track  12 , thereby preventing drivers and passengers from exiting their vehicle  16  while the vehicle  16  is on the TEV track  12 . Each vehicle  16  can transmit status information to the central controller  18 . The status information can include, for example, an identifier unique to each vehicle  16 ; the location and speed of the vehicle  16 ; and an indication whether all of the exterior access points of the vehicle  16  are closed and locked. The controller  18  can be programmed to de-energize one or more sections  14  of the TEV track  12  upon receiving an indication that a vehicle  16  located on or near those sections  14  is stopped, and/or has one or more open exterior access points. This feature can reduce or eliminate the electrocution hazard to drivers and passengers who exit their vehicle  16  while the vehicle  16  is on the TEV track  12 . 
     The vehicles  16  can be equipped with one or more sensors  123  that detect the presence of fire and smoke in or around the vehicle  16 . The sensors  123  also can be installed on the TEV track  12 . The sensors  123  can be the communicatively coupled to the central controller  18 , as shown schematically in  FIG. 6 . A fire on a TEV track  12  can initiate, for example, in the battery  102  of a vehicle  16 . A battery fire, with its enormous release of smoke, can present an extreme hazard to drivers and passengers; and a full-scale fire in a lithium-ion battery can be unstoppable with present firefighting methods due to the flammable electrolyte of such batteries. The central controller  18  can be configured so that, upon detection of smoke or fire by one or more of the sensors  123  in or proximate a particular vehicle  16 , the central controller  18  will guide that vehicle  16  so as to expel the vehicle  16  from the TEV track  12  at the next exit. The central controller  18  subsequently will direct the vehicle  16  to a predetermined station, or “safe place;” and will stop the vehicle  16  and unlock the exterior access points once the vehicle  16  has reached the safe place so that the driver and passengers can exit the vehicle  16  to safety. The system  10  includes multiple substations  310  that supply the TEV tracks  12  with electric power drawn from the local electric grid or other sources. The substations  310  are shown in  FIGS. 2 and 6 . Each substation  310  provides power to an associated track section  14 . Each substation  310  is electrically connected to the first and second rails  30 ,  32  of its associated track section  14 , as illustrated in  FIG. 2 . As noted above, each track section  14  of the exemplary system  10  includes one continuous first rail  30  and one continuous second rail  32 , each having a length of about 2,460 feet (about 750 meters). Thus, each substation  310  supplies power to one corresponding set of 750-meter-long continuous first and second rails  30 ,  32  of the TEV track  12 . When two or more TEV tracks  12  are arranged side by side as shown, for example, in  FIGS. 1, 7, and 8 , one substation  310  can be used to supply electric power to the first and second rails  30 ,  32  of adjacent, i.e., side by side, track sections  14  of the multiple TEV tracks  12 . The substation  310  supplies 400 volts direct current (VDC) power to the first rail  30 , and the vehicle  16  draws power from the first rail  30  by way of the electrical pickup  116  in contact with the first rail  30 . The second rail  32  acts as a ground that, along with the associated electrical pickup  116 , completes the circuit between the vehicle  16  and the substation  310 . In alternative embodiments, the substation  310  can supply power to the second rail  32 ; and the first rail  30  can act as a ground that completes the circuit between the vehicle  16  and the substation  310 . Also, the supply voltage can be greater or less than 400 VDC; for example, alternative embodiments of the system  10  can operate at voltages of 750 VDC or 1,000 VDC. Also, AC power can be used in lieu of DC power in other alternative embodiments. Each substation  310  can be communicatively coupled to the central controller  18  of the system  10  by a suitable means such as radio-frequency (RF) transmission, Wi-Fi, a wired connection, etc. 
     Because each substation  310  supplies one track section  14 , the spacing between adjacent substations  310  is about equal to the lengths of the individual first and second rails  30 ,  32 . As discussed above, increasing the lengths of the first and second rails  30 ,  32  can necessitate forming the first and second rails  30 ,  32  from a higher-conductivity, and more expensive, material; and can make it difficult to transport, store, and handle the first and second rails  30 ,  32 . On the other hand, longer-length rails increase the spacing between the substations  310 , thereby reducing the costs associated with procuring, installing, and maintaining the substations  310 . Thus, because the optimal length for the first and second rails  30 ,  32  is dependent upon these, and possibly other competing factors, the optimal length can vary between applications. 
     The system  10  can be configured to store energy produced by power plants or other sources at night or during other times of off-peak demand for electricity generation. The energy can be stored in large, stationary batteries  312  located in the substations  310 . One of the batteries  312  is depicted in  FIG. 2 . This storage capacity can be used to reduce the draw of the system  10  from the electrical grid during periods of peak electrical demand, without requiring the vehicles  16  to draw power from their on-board batteries  102 . Also, if rush-hour traffic volume results in excessive power requirements by the system  10 , the demand on the power grid can be reduced through the use of the standby batteries  312  at the substations  310 , and if necessary, the batteries  102  of the individual vehicles  16 . 
     As noted above, the TEV track  12  is configured to operate on direct-current (DC) electric power, with supply voltages as high as 1,000 VDC or greater. It is believed that this relatively high voltage can be used safely, i.e., with a low risk of electrocution to humans, due to the above-noted provisions that de-energize all or a portion of the TEV track  12  when a vehicle is stopped on the TEV track  12 , or when a door or other exterior access point of a vehicle  16  on the TEV track  12  is opened; and because the TEV track  12  has provisions that restrict pedestrians from entering onto the TEV track  12 . 
     The relatively high DC voltage, which results in a lower current flow through the first and second rails  30 ,  32 , provides greater operating efficiency in comparison to a system that operates at a lower voltage, and can reduce the required size, and cost, of the first and second conductors  20 . Operating voltages for DC-powered passenger trains, by contrast, typically do not exceed 750 VDC due to the proximity of the ground-mounted power-supply rail to humans. 
     In alternative embodiments, the vehicle  16  can be configured to operate on alternating current (AC) provided via the first and second rails  30 ,  32 , or via AC induction hardware on the TEV track  12  and the vehicle  16 . In such applications, the vehicle  16  can be equipped with a transformer-rectifier unit to transform the alternating current into direct current having a voltage, such as 400 VDC, suitable for the electric drive motor  100  and other electrical components of the vehicle  16 . 
     The relatively high voltages that can be provided to an AC system can yield high operating efficiencies; and can reduce capital costs for the system  10  by allowing the first and second rails  30 ,  32  to have a smaller cross-sectional area in comparison to conductors in a lower-voltage, higher-current DC system of similar capacity. These advantages, however, can be offset by the requirement for a transformer-rectifier unit to transform the AC power into the lower-voltage DC power suitable for powering the drive motor  100  and the other electrical components of the vehicle  16 . The presence of the transformer-rectifier can make the vehicle  16  substantially larger and heavier than a comparable DC-powered vehicle. The size and weight of the transformer-rectifier unit can be minimized, however, through the use of advanced power-conditioning electronics, and an aluminum-wound transformer with concentric windings. The size and weight of the transformer-rectifier also can be minimized by reducing the supply voltage of the AC power, in a trade-off between power-transmission efficiency, and the size and weight of the transformer-rectifier. 
     While high operating efficiencies can be achieved with operating voltages of 5,000 volts alternating current (VAC) to 15,000 VAC, voltages above 5,000 VAC can present a substantial electrocution hazard. Thus, an illustrative AC-based system may have a supply voltage of about 5,000 VAC; alternatively, the system can be configured to operate with a supply voltage of about 2,000 VAC, to facilitate the use of a smaller and lighter transformer-rectifier. 
     Due the electrocution hazard presented by the relatively high supply voltage of an AC-based system, a power-supplying system can be mounted above the roadway and the vehicle  16 , in a manner similar to the overhead cable arrangements in high-speed rail systems.  FIG. 16  is an illustrative example of such a system, and depicts a system  300  that includes a first conductor in the form of a rod  302 , and a second conductor in the form of a rod  304 . The rods  302 ,  304  are suspended from the roof panel  204  of each track section  14 , by way of electrically-insulating supports  306 . The rods  302 ,  304  can be formed from, for example, aluminum or copper. Electrically-insulating barriers  307  are positioned between, and outward of the rods  302 ,  304 . The barriers  307  prevent contact between the rods  302 ,  304 , and partially shield the rods  302 ,  304  from contact with pedestrians. 
     Electrical pickups  116   a , similar to the electrical pickups  116 , are mounted on the roof of the vehicle  16 , and are configured to extend upward, so as to contact the rods  302 ,  304 , when the vehicle  16  is on a TEV track of the system  300 .  FIG. 17  depicts an alternative embodiment of the electrical pickups  116   a  in the form of an electrical pickup  116   b  having Y-shaped brushes  310 ; the Y-shape of the brushes  310  helps the brushes  310  maintain contact with the power-supply cables as the vehicle  16  drifts from side to side during normal travel along the TEV track  12 . Other alternative embodiments (not shown) can include U-shaped brushes, and brushes having other shapes. 
     The track sections  14  are relatively light, and thus can be stacked one on top of another in double-deck fashion using a suitable framework, thereby doubling the capacity the TEV track  12 . Also, the track sections  14  can be raised or elevated above the ground, so that the TEV track  12  does not interfere with human traffic or the migration paths of animals; to avoid natural and man-made obstacles; to help minimize the impact of the TEV track  12  on environmentally sensitive areas such as wetlands; etc. Because the vehicle  16  has an alternative power source in the form of the battery  102 , the entire TEV track  12  does not need to be electrified. The vehicle  16  can be operated on a non-electrified portion of the TEV track  12  using its battery  102  as the sole power source for the drive motor  100 . For example, track sections  14  on a downhill portion of the TEV track  12  do not need to be electrified, as gravity can provide the primary motive force for the vehicle  16  on such downhill portions; and the vehicle  16  itself, powered by the battery  102  and/or its own momentum, can provide any additional motive force that may be required. 
     The vehicle battery  102  can be used to supplement the power provided by the TEV track  12  on uphill sections of the roadway, and on other localized portions of the roadway at which the vehicle power demand is relatively high. The ability to supplement the power from the TEV track  12  using the on-board power of the vehicle  16  can eliminate the need for higher capacity, and more expensive, conductors on localized portions of the TEV track  12  at which the power demand is relatively high. 
     The entrances and exits  40  on the TEV track  12  are not electrified, to permit the vehicles  16  to freely enter and exit the roadway. In particular, the first and second rails  30 ,  32  are not installed at, and proximate the exits and entrances  40 . For example, the first and second rails  30 ,  32  can be eliminated over a distance of about 200 meters (about 650 feet) at and near each entrance and exit  40 , as shown in  FIGS. 1 and 7 . As a result of this feature, the upper surface of the base  29  is smooth and unobstructed at and near the entrances and exits  40 , providing the vehicles  16  with an unobstructed path onto, or off of the roadway. 
     A vehicle  16  can enter the TEV track  12  by driving onto the TEV track  12  by way of an entrance  40 . The electrical pickups  116  of the vehicle  16  are maintained in their retracted, or stowed position, and the vehicle  16  is powered by its on-board battery  102  as the vehicle  16  enters the TEV track  12 . Upon crossing onto the entrance  40 , the vehicle  16  travels along a relatively short, non-electrified acceleration lane that forms part of the entrance  40 . When positioned on the acceleration lane, the vehicle  16  can increase its speed prior to entering the TEV track  12 . Once the vehicle  16  has entered onto the TEV track  12  and has advanced to a position where the vehicle  16  is positioned over the first and second rails  30 ,  32 , the controller  18  can command the electrical pickups  116  to move into their deployed positions to establish electrical contact between the vehicle  16  and the TEV track  12 , thereby allowing the vehicle  16  to draw power from the TEV track  12 . The command to extend the electrical pickups  116  can be generated automatically, by the control unit  112  of the vehicle  16 ; or by an input from the driver. 
     When the vehicle  16  is approaching an exit  40 , the control unit  112  can command the electrical pickups  116  to move into their retracted positions. The command to retract the electrical pickups  116  can be generated automatically, by the control unit  112 ; or by an input from the driver. Upon reaching the exit, the vehicle  16  can exit the TEV track  12  by driving across the unobstructed portion of the TEV track  12  resulting from the absence of the first and second rails  30 ,  32 , and onto a relatively short, non-electrified deceleration lane that forms part of the exit  40 . Once positioned on the deceleration lane, the vehicle  16  can reduce its speed through regenerative or other types of braking; the vehicle  16  then can exit the TEV track  12  under its own momentum, and if necessary, under the power of its battery  102 . 
     The system  10  can be equipped with provisions, discussed above in relation to the gap  209 , that lift and then lower the electrical pickups  116  of vehicles  16  that are not entering or exiting the roadway as those vehicles  116  traverse the non-electrified portions of the roadway, to prevent damage to the brushes  118 . The through-traffic vehicles  16  can continue ahead on their momentum, and if necessary, using their on-board batteries  102 , until the vehicles  16  establish contact with the first and second rails  30 ,  32  on the other side of non-electrified portion of the TEV track  12 . Also, the through traffic does not need to slow down to permit the exiting vehicles  16  to leave the TEV track  12 . High-speed trains, by contrast, must repeatedly slow down and stop at different stations for several minutes or more, and thereby lose much of their speed advantage. For example, vehicles  16  driving continuously at 120 miles per hour (193 kilometers per hour) have a similar average speed to that of high speed trains that can reach speeds of 180 miles per hour (290 kilometers per hour) but must stop intermittently to pick up and discharge passengers. 
     In multi-lane systems such as the system  15  shown in  FIG. 7 , non-electrified transfer points  42  can be provided at intervals along the various TEV tracks  12  to facilitate lane changes by the vehicles  16 . This feature can provide the central controller  18  with flexibility to direct vehicles  16  to different lanes, i.e., onto different TEV tracks  12  carrying vehicles in the same direction, so as to manage the traffic flow within the system  15 . This feature also permits the vehicles  16  to enter and exit the system  15  by way of a single series of entrances and exits  40  that adjoin only one of the lanes. 
     As another example of non-electrified portions of the TEV track  12 , minor portions of the TEV track  12  that interconnect major portions of the TEV track  12  and run several miles or more in length can be non-electrified. The vehicle  16  can traverse such minor sections using power from its battery  102 , and/or its own momentum. The non-electrification of such light-duty portions of the TEV track  12  can eliminate the need to equip those sections of the TEV track  12  with the first and second rails  30 ,  32 , thereby reducing the overall cost of the TEV track  12 . 
     Upon reaching, or returning to, an electrified portion of the TEV track  12 , the vehicle  16  can draw its electric power from the TEV track  12  by way of the first and second rails  30 ,  32 ; and the battery  102  can be recharged by the electric power being drawn from the TEV track  12 . Because the battery  102  is used as a secondary power source when the vehicle  16  is operating on the TEV track  12 , the battery  102  does not need to be recharged immediately; hence, the charging process can occur relatively slowly, avoiding the inefficiencies and energy losses associated with fast charging. 
     Also, in contrast to a roadway system which is electrified intermittently in discrete sections spaced apart in a consistent, repetitive manner, most of the TEV track  12  is electrified. Consequently, most of the energy drawn by the vehicle  16  during long-distance cruise and other operating conditions is used directly by the drive motor  100 ; and little if any energy is lost to the recharging process for the battery  102 . In an intermittently-electrified roadway, by contrast, the battery is constantly undergoing a discharge-recharge cycle. This can result in substantial energy losses associated with the recharging process, can reduce the service life of the battery  102 , and can necessitate a larger and heavier battery  102  than otherwise would be needed. 
     The central controller  18  comprises a processor, such as a microprocessor; a memory device communicatively coupled to the processor via an internal bus; and computer-executable instructions stored on the memory device and executable by the processor. The controller  18  also comprises an input-output bus, and an input-output interface communicatively coupled to the processor by way of the input-output bus. The computer-executable instructions are configured so that the computer-executable instructions, when executed by the processor, cause the controller  18  to carry out the various logical functions described herein. 
     d. Operation 
     As discussed above, each vehicle  16  operates autonomously, under the control of the central controller  18  and without input from the driver, whenever the vehicle  16  is traveling on the TEV track  12 . Because the controller  18  can simultaneously control the respective positions of all the vehicles  16  operating on the TEV track  12 , the spacing between vehicles  16  operating in the same lane, i.e., on the same TEV track  12 , can be minimal, while still maintaining a high standard of safety. For example, it is believed that the controller  18  can safely maintain a back-to-front spacing of about 24 inches (about 61 cm) under dry road conditions, and at speeds of about 60 miles per hour (96 kilometers per hour) to about 120 miles per hour (193 kilometers per hour), depending on whether a particular TEV track  12  is being used for express or local travel. 
     The ability to safely operate the vehicles  16  in close proximity to each other permits the vehicles  16  to be operated in tightly-spaced groups in the form of, for example, ten-vehicle platoons or 30-vehicle convoys. As an example,  FIG. 7  depicts a platoon traveling along the high-speed TEV track  12   a  (only six of the ten vehicles  16  in the platoon are shown in  FIG. 7 , for illustrative clarity). Operating multiple vehicles  16  in this manner can substantially reduce the aggregate air resistance of the vehicles  16 , thereby reducing the overall energy consumption of the platooned or convoyed vehicles  16 . For, example, it is estimated that operating the vehicles in a platooned or convoyed manner can produce an overall reduction in aerodynamic drag of about 40 percent. Also, because it is highly unlikely that vehicles  16  traveling at the same speed and in the same direction will collide with each other, operating the vehicles  16  in a platooned, convoyed, or other grouped manner can enhance the safety of travel on the TEV track  12 . 
     Also, operating the vehicles  16  in platoons, convoys, or other closely-spaced groupings can substantially increase the traffic-carrying capacity of the TEV track  12 . For example, if the fast lane of a normal three-lane highway were converted to an electrified TEV track  12  carrying only the autonomously-controlled vehicles  16 , the TEV track  12  would be able to carry at least ten times more vehicles  16  than each of the conventional non-electrified lanes. This would allow the modified three-lane highway, i.e., a highway made up of three TEV tracks  12 , to carry as much traffic as a conventional twelve-lane highway. 
     As noted above, it is believed that the vehicles  16  can be operated in a platooned or convoyed manner, under dry road conditions, at speeds of up to 120 miles per hour (193 kilometers per hour) on individual TEV tracks  12  dedicated to long-distance or express travel; and at speeds of up to 60 miles per hour (96 kilometers per hour) on TEV tracks  12  dedicated to shorter distance or local travel. These speeds can be reduced automatically, and in real-time, by the central controller  18  when road conditions are wet, snowy, or icy; or when maintenance, accidents, or other factors warrant reduced speeds. 
     The vehicle  16  can transmit its desired destination to the central controller  18  via the transceivers  33 ,  114 . The vehicle  16  can include a user interface  160  communicatively coupled to the control unit  112 , as shown in  FIG. 6 . The user interface  160  permits the driver or other user to input the destination and other information into the control unit  112 , and to monitor the position and other status information for the vehicle  16 . The user interface  160  can be, for example, a keypad and a display. In addition, the control unit  112  can be configured to receive inputs from, and provide status information to a remote device, such as a smart phone, via a wi-fi or cellular connection. 
     The vehicle  16  can be driven onto the TEV track  12  using the power supplied by its internal battery  102 , in substantially the same manner as when entering a conventional highway. The entrances  40  to the TEV track  12  can be equipped with a barrier, such as a gate  150 , for preventing conventional vehicles from gaining access to the TEV track  12 . The gate  150  is depicted in  FIGS. 2 and 6 . The gate  150  also can be used to deny access to vehicles  16  that are not properly configured for use on the TEV track  12 , such as vehicles  16  equipped with external luggage racks, pods, or other drag-inducing devices; vehicles  12  hitched to trailers; and pickup trucks with open beds, which can induce high levels of drag and raise safety concerns relating to unrestrained items flying out of the bed at high speeds. 
     The central controller  18  can assume control of the vehicle  16  as the central controller  18  commands the gate  150  to open. The controller  18 , through inputs to the control unit  112 , can guide the vehicle  16  onto the TEV track  12  in a manner that maintains separation between the vehicle  16  and the other vehicles  16  operating on the TEV track  12 . The control unit  112  of the vehicle  16  can command the electrical pickups  116  to extend so that the attached brushes  118  contact the respective first and second rails  30 ,  32  once the electrical pickups  116  have aligned with the first and second rails  30 ,  32 . The controller  18 , via inputs to the control unit  112 , subsequently can the guide the vehicle  16  so as to position the vehicle  16  in a platoon, convoy, or other type of grouping with other vehicles  16 . 
     Because the vehicle  16  draws its power from the TEV track  12 , and the driver does not need to drive or otherwise control the vehicle  16 , the vehicle  16  in theory can travel an unlimited distance without stopping. From a practical standpoint, however, the non-stop range of the vehicle  16  is dictated by the needs of the driver and passengers for rest stops. In scenarios where the vehicle  16  is being ferried without a driver or passengers, the vehicle  16  can make a cross-country or other long-distance trip under the autonomous control of the central control unit  112 , without stopping. 
     As the vehicle  16  reaches the exit  40  corresponding to its destination, the control unit  112  can command the electrical pickups  116  to retract; and the central controller  18 , through inputs to the control unit  112 , can guide the vehicle  16  to, and through the exit  40  in the manner described above. Because the vehicle  16  operates on conventional rubber-based automobile tires  108  without the use of rails, the exiting procedure is substantially equivalent to exiting a regular highway; and the exit can be performed without the use of complicated hardware like railway switches or points. Once the vehicle  16  has exited the TEV track  12 , the vehicle  16  can be driven to its final destination under semi-autonomous control, or under fully manual control exercised by the driver. 
     The electrified TEV track  12  is believed to among the most efficient ways to propel electrically-powered vehicles “on the fly,” and thus has the potential to achieve substantial reductions in CO 2  emissions world-wide, notwithstanding that reducing CO 2  emissions from highway vehicles is a relatively difficult problem because motorized vehicles, by their nature, are mobile. 
     The cost of the electricity consumed by the vehicle  16  can be monitored and recorded by the central control unit  112  or other suitable means. The electricity cost can be automatically billed to, and paid by the owner of the vehicle  16 , as in systems now in use on toll roads. Also, the ability to draw electric power from the TEV track  12  eliminates the need to fill up a gasoline tank at a gas station, and the need to stop to recharge the battery  102  using a stationary charger. 
     The system  10  provides the users with the ability to drive from home to a local entrance  40  for the TEV track  12  in the family car, i.e., the vehicle  16 . Once travel is established on the TEV track  12 , the driver and passengers can sleep while the vehicle  16  cruises safely at, for example, 120 miles per hour (193 kilometers per hour) for hundreds of miles. The driver and passengers can be woken up in time for a programmed exit from the TEV track  12 . The remainder of the journey can be driven manually over non-electrified secondary roads to the final destination. In many if not all cases, it is believed that a door to door journey using the TEV track  12  will be quicker than that of a high-speed train, which typically is restricted to travel between a relatively small number of terminals located in large cities. Moreover, the vehicles  16  are believed to be more comfortable, convenient, quiet, and hygienic than trains. Although the TEV track  12  is configured to accommodate the electric vehicles  16 , vehicles powered by internal combustion engines also can operate on the TEV track  12 , if such vehicles are configured to be autonomously controlled by the central controller  18 ; and subject to restrictions against operating in portions of the TEV track  12 , such as tunnels, that may not be sufficiently ventilated to remove the exhaust gases generated by the internal combustion engines. As noted above, allowing vehicles powered by internal combustion engines to use the TEV track  12  can be implemented, for example, as a temporary measure to increase toll revenue during the early stages of operation of the TEV track  12 . 
     It is believed that overall travel times on the TEV track  12  will be comparable to, or more favorable than those of high-speed trains. This is due, in part, to the ability to economically decentralize the TEV track  12  to reach a relatively large number of destinations, in comparison to the relatively limited number of centralized stations typically available to a high-speed rail system; and because the vehicles  16 , after leaving the TEV track  12 , can be driven directly to their final destinations using the internal battery  102  as their power source. Also, unlike most if not all high-speed rail systems, it is believed that the construction and operating costs for the TEV track  12  can be recovered entirely through toll revenues. 
     The TEV track  12  can accommodate both private and public service vehicles that meet the safety and size requirements for the TEV track  12 . The vehicles  16  can be owned and operated by individuals; 
     and by commercial enterprises such as taxi companies, courier delivery services, etc. Government ownership may be preferred in some countries, but private capital would generally be a preferred option in most of the world. 
     Due to the automated operation and modular construction of the TEV track  12 , it is believed that the number of employees required to operate and maintain the TEV track  12  is a small fraction of that required by a rail system or a major highway system; this obviates the need to rely on large government-run agencies to maintain the TEV track  12  in an operational condition. Although government ownership for the TEV track  12  may be preferred in some countries, it is believed that funding by private capital, or public-private partnerships, would be the preferred option for initial funding in most of the world, with return revenue being generated by tolls once the TEV track  12  becomes operational. 
     In applications where the TEV track  12  is subject to an initial start-up and acceptance period, the first and second rails  30 ,  32  initially can be made relatively thin, to save costs. As time passes and more vehicles  16  begin to use the TEV track  12 , the first and second rails  30 ,  32  be strengthened and made more durable by bolting on or otherwise adding more conductor material to the first and second rails  30 ,  32 ; or, in applications using modular rails such as the first and second rail  30   b ,  32   b , by adding more electrically-conductive elements. 
     Portions of the TEV track  12  may be enclosed, and air may be partially or fully evacuated from the enclosed portions to reduce aerodynamic drag on the vehicle  16  and thereby save energy. Air also can be evacuated from underground tunnels traversed by the TEV track  12 . The interior of the vehicle  16  can be pressurized for passenger comfort as the vehicle  16  passes through areas in which the air has been evacuated. 
     If a particular vehicle  16  breaks down or otherwise stops running on the TEV track  12 , the vehicle or vehicles  16  located behind the disabled vehicle  16  can push the disabled vehicle  16  to the next exit  40 , so that the disabled vehicle  16  can be removed from the TEV track  12  and repaired. The vehicles  16  can be equipped with bumpers to facilitate pushing other vehicles  16  in this manner. This feature can help eliminate delays caused by disabled vehicles  16 . 
     It is estimated that the vehicles  16  can come to a complete stop on the TEV track  12  in about 50 yards (46 meters), from a speed of 120 miles per hour (193 kilometers per hour) and under dry road conditions. High-speed trains, by contrast, may require one-half mile to stop under dry conditions, and even more under wet conditions. Thus, even if a portion of the TEV track  12  located 100 yards (91 meters) from a platoon or convoy of the vehicles  16  was intentionally or unintentionally damaged or blocked, the lead vehicle  16  in the platoon or convoy could brake heavily and stop well before the damaged section. Even if a vehicle  16  did reach a damaged or blocked portion of the TEV track  12 , it is believed that the many effective safety features of modern automobiles, such as crumple zones, air bags, and safety belts, would protect the vehicle occupants from serious harm. By contrast, high-speed trains generally are not equipped with such features to protect passengers in the event of a crash. 
     The direct-current power supply of the system  10  is relatively simple, and utilizes existing technologies. Therefore, the system  10  can be implemented relatively quickly, thereby allowing major countries around the world to reduce their CO 2  production from cars and similar vehicles relatively quickly. This is particularly significant in view of the present failure of hydrogen power to provide the earlier-predicted reductions in CO 2  emissions.