A Dual Mode Transportation System

FIELD OF THE INVENTION:

This application relates to dual-mode transportation systems, specifically to vehicles operating on both road and track systems.

BACKGROUND - PRIORART:

The common automobile is a first choice for many transportation needs. Personal road cars are very convenient, offering privacy, flexibility, and ready-when-you-are, direct door-to- door transportation service. Indeed, cars are so fundamentally incorporated into our everyday life that few people in the developed world could imagine living without one.

However, there is a growing recognition that the automobile is unsustainable in its current form. Cars require too much energy to move, and we continue to power them with fossil fuels, to the detriment of the global environment. Our roads are crowded and traffic jams up, wasting fuel and causing headaches. Driving is for many people a waste of valuable time. And of course, cars are unacceptably dangerous, with tens of thousands of people dying on the road every year.

The world is in desperate need of a transportation revolution, and the "dual mode" concept promises a solution. A vehicle that can travel on steel tracks as easily as it travels on paved roads could potentially combine all the conveniences of the private road car with the higher capacity and greater efficiency of rail. Such a solution could also conceivably provide for driverless operation, adding even more convenience to an already preferred choice. Many have been searching for a cost-effective way to make all this possible, but decades of effort have not yet borne fruit.

A fundamental problem is how to keep a vehicle in the designated travel lane. Conventional road vehicles use "traction wheels" - that is, they use pneumatic rubber wheels on a rough paved surface to generate a very large friction force to keep the wheels from sliding off the road. A driver can then point the wheels in the right direction to drive the car down the lane.

However, this force of friction and the rolling resistance of a pneumatic rubber tire increase resistance to a vehicle's travel and raise energy requirements. And the free-ranging nature of a traction wheel system requires the driver of each car to maintain a "personal space" around his or her vehicle. Cars can easily collide, so drivers must slow down as traffic density increases beyond a certain point, resulting in traffic jams. And cars still end up crashing and sliding off the road anyways.

An alternative to the traction wheel is the "rolling wheel." A rolling wheel has greatly reduced rolling resistance and supports the weight of a vehicle without generating a large force of friction. A steel rolling wheel on a steel rail rolls much more freely than a traction wheel, reducing energy requirements. However, it requires an alternative means for keeping vehicles in the travel lane since it lacks traction with the road and cannot steer.

One conventional solution for keeping a rolling-wheel vehicle in its travel lane is to provide its rolling wheels with flanges that glide over the side surface of the rails to prevent excessive lateral forces from derailing the vehicle. However, the flange creates problems for the would-be transit solution, because it travels below the primary support surface of the rail. The running surface of the rails must then have gaps to allow vehicles on different tracks to cross over, and special pieces called "frogs" are required to lift passing cars up onto the flanges of their wheels so that they may cross these gaps without falling into them. The flange also makes switching from one track to another an expensive undertaking, typically requiring switches that have moving parts.

The flanged wheel works well enough for large, heavy-duty lines because the trains are big enough and there are few enough junctions that the cost of these track elements can be justified. But the system we seek herein to build will have far too many junctions and branches and far too many vehicles each going their separate way. These kinds of track elements will not be of any use; they are simply too costly to install and maintain.

Another solution for keeping a rolling-wheel vehicle in its travel lane is to provide a vertical guide rail along the travel lane. A second set of rolling wheels on the vehicle with vertical axes of rotation can then run along the vertical face of this guide rail and keep the vehicle in the travel lane. The problem with this solution is that the travel lane is no longer flat, and vehicles cannot cross over it easily. This typically means that the system must be elevated or in a special right-of-way, dramatically increasing the cost of the system. It also usually means that vehicles can only enter and exit the system at a limited number of special locations, reducing the convenience and flexibility of the system.

Yet another solution for keeping rolling-wheel vehicles in their travel lanes is to put the rolling wheels in a potential-energy well. Either the track or the lane itself is at a lower elevation than the surrounding area, and gravity keeps a vehicle from leaving the lane. This is the most promising solution since it potentially allows for travel lanes to remain flat and continuously accessible, but so far, a cost-effective method for switching tracks has not been found. Many solutions overcome the problem of moving track switches only by substituting them for an equally-complex switching mechanism on the vehicle. And few are able to retain the traction wheel's capabilities for acceleration, deceleration, and on-grade operation, which is essential for mixing with conventional traffic.

SUMMARY

It is the object of the current application to disclose a true dual-mode transportation system. Vehicles will retain every bit of functionality and convenience that they currently possess, while at the same time achieving the efficiency, capacity, and guidance benefits of traveling on rails. They will be able to enter and exit the track system at virtually any location. The travel lanes will remain flat so that the system can be added to existing roadways. Vehicles will be able to use traction wheels to match the performance of the traffic they will mix with. Existing vehicles will be convertible to run on the new system with minimal modification so that the system can be built and adopted quickly. And the solution is simple and cost-effective.

Vehicles will be given two sets of wheels: one is a traction- wheel system for driving on a flat road in "road mode," and the other is a rolling-wheel system designed for operation in a trough-shaped rail in "rail mode." The vehicle can use the two wheel systems alternately or simultaneously to achieve true dual-mode functionality. Vehicles will be able to use their traction-wheel system in both road mode and rail mode, allowing them to drive normally on a flat road, and also giving them substantial traction performance in rail mode. The task of switching rails is accomplished by raising the rolling wheels and using the traction wheels for guidance at switches.

DETAILED DESCRIPTION

*** A SYSTEM ***

This application discloses a transportation system comprising a travel lane and a wheel system that vehicles will use to travel in mat lane. Both the travel lane and the wheel system will be configured so that vehicles can use two different types of wheels alternately or simultaneously as they travel down the lane. One of these types of wheels will seek to maximize friction and traction with the travel lane when in use; these are herein referred to as "traction wheels," and they will be arranged in a traction-wheel subsystem. The other of these types of wheels will seek to minimize friction and rolling resistance when in use; these are herein referred to as "rolling wheels," and they will be arranged in a rolling-wheel subsystem. The wheel system is comprised of these two subsystems together.

A plurality of travel lanes will be arranged in a network, and vehicles will be able to travel in this network in two different modes. Vehicles will be able to function in a "road mode," wherein they will use their traction- wheel subsystem to drive on a flat road in a manner substantially similar to today's common automobiles. And vehicles will also be able to travel in a "track mode," wherein they will use their rolling-wheel subsystem, assisted by their traction- wheel subsystem, to drive on tracks embedded in the travel lane.

*** THE TRAVEL LANE ***

One embodiment of the travel lane is shown in cross-section in Fig. 1. In a roadbed or other substantially-flat support surface 1, a trench 2 is created down the length of the travel lane for receiving the body of an elongate rail 3. The rail 3 is then secured into the trench 2 using a suitable adhesive 4. The rail 3 is shaped so that it distributes weight through the surface of the road 1 using flanges 5 that extend outwards laterally from the top of the rail 3. Finally, a buildup layer of pavement 6 is provided around the rail 3 so that the surface of the road 1 is brought even with the top of the rail 3 and the road 1 remains substantially flat in the vicinity of the rail 3. This track system is a preferred solution by virtue of its reduced cost and simplified installation, and it is substantially similar to that disclosed in U.S. Patent 5513797.

The rail 3 in Fig. 1 is surface-supported and secured in place with adhesive 4, though it will be readily understood that any type of rail, roadbed, and fastening systems may be used to construct the travel lanes. Higher-load applications, for instance, may require a more substantial foundation than is provided in the above embodiment. Or the road 1 may have a structure that allows both the rail 3 and its flanges 5 to be sunk into the trench 2, and the build-up layer of pavement 6 will not be necessary. Or perhaps the support surface 1 cannot provide the trench 2, and the rail 3 must sit on top of the support surface 1 and the build-up layer 6 will have to be thicker.

These kinds of changes are irrelevant: the subject of the current application is not the rail system, per se, but the topography of the travel lane's running surface and the configuration of the wheel system that interacts with it. Any road and rail system is suitable which provides the essentials of the required running surface, as shown in Fig. 2.

Fig. 2 shows the essentials of the travel lane's running surface in cross-section. The surface of the road 1 shall be substantially flat, with the exception of a grooved or trough-shaped track 7 which extends down the length of the travel lane. The road surface 1 shall be made of a material with a large coefficient of friction, e.g. concrete or asphalt cement. The track 7 shall be made of a material with a low coefficient of friction and a high degree of hardness, e.g. steel, and the trough in the track 7 shall be narrow enough that vehicles' traction wheels may pass over it without falling in. And as a matter of housekeeping, the track 7 may optionally have a recess 8 at the bottom to trap small pieces of debris out of the way.

The flat road 1 is provided so that vehicles can get traction with the travel lane using their traction-wheel subsystems. The traction they so acquire will prevent them from unintentionally deviating from their path during road-mode travel. And the road's traction surface 1 is also indispensable for vehicles traveling in track mode, as it will allow them to switch tracks and efficiently accelerate, decelerate, and climb grades.

The track 7 is provided so that vehicles can shift their weight onto their rolling-wheel subsystems where it will impede their travel less greatly. The track 7 is a potential-energy well where rolling wheels will be constrained to travel, and vehicles traveling in track mode would have to overcome gravity and climb over a side wall 9 of the track 7 to leave the travel lane unintentionally. Thus, the track 7 not only allows vehicles to increase the efficiency of their travel, but it will also guide vehicles to stay in their respective lanes during driverless operation.

*** THE NETWORK ***

The transportation system's travel network will be comprised of a plurality of these travel lanes connected to each other. The respective road surfaces 1 of these lanes shall be continuous with each other, and their tracks 7 shall be connected.

Where the tracks 7 in these travel lanes are supplied and installed in pieces, it is preferred that joining pieces of track are welded together wherever practical to provide stronger connections and a smoother ride. But again, these are details of the rail system and are irrelevant to the topography of the running surface of the travel lane. The only requirement that my transportation system places on the joining of tracks is that vehicles must be able to pass over any joints without significant disruption.

The tracks 7 of separate travel lanes shall be connected to each other, and Fig. 3 shows a track splitter which vehicles will use to switch off of the track 7 they are on, and onto a diverging track T while in track mode. The splitter is connected to incoming and outgoing tracks at the appropriate points 10, and has a raised barrier 11.

The track 7, recall, is a potential-energy well, where gravity keeps vehicles from derailing. In Fig. 3, shading serves to indicate the relative height of the running surface in the region of the splitter, and thus the path that a wheel will tend to follow. The surrounding road 1 is at the highest elevation, indicated by darker shading. Both the continuing track 7 and the diverging track 7' are lower than the road surface 1, and their lighter shading indicates their lower elevation. The barrier 11 is at a height in between, and its medium shading reflects a height between that of the track 7 and the road 1. The shade gradient of the barrier 11 illustrates a sharp height difference where it runs alongside the continuing track 7, and a gradual return to the minimum height as it extends down the diverging track T. Thus it can be seen that the barrier 11 presents a wall that will keep vehicles on the continuing track 7 unless they take action to pass over the barrier 11 to get onto the diverging track T.

In order to merge two tracks into one, a piece identical to the splitter will be used, just in reverse and without the barrier 11. It will be apparent at this point that the tracks 7 in the network are intended for use in only one direction of travel.

The transportation system herein described is contemplated as being used for vehicles that are substantially similar in weight to the motorcycles, automobiles and tractor-trailers which are in widespread use today. Thus, while the network of travel lanes may be constructed for heavier trains which require the use of frogs where tracks 7 intersect, the frogs are not necessarily necessary for a lighter-weight application. So as shown in Fig. 4, the first track 7 and an intersecting track 7" can be crossed over each other with a lap-joint, where they are simply notched so that they lay flat when one is placed on top of the other.

The bottom portion of the first track 7 will have to be sufficiently thick in the vicinity of the joint to accommodate the notch without significant weakening, and the running surface of the intersecting track 7" should be made flat, if it is provided with the recess 8 at the bottom.

Since the tracks 7 are intended for one-way travel only, any joint between tracks that is not welded can be constructed so that passing vehicles will fall from one track onto the next, rather than strike an edge. This will reduce noise and impact stresses and make for a more ^• ; comfortable ride. Fig. 4 shows an example of this. The running surface of the intersecting track 7" is slightly lower than that of the first track 7. And the first track 7 is ground down on the far side of the intersection to provide a ramp 12 for exiting vehicles. Vehicles passing through the intersection on the intersecting track 7" will experience no track discontinuity, and vehicles passing through on die first track 7 will follow a trajectory 13 that is free of sudden jolts. Vehicles will take a short drop as they fall from the first track 7 onto the crossing track 7", and then on another short drop as they fall from the crossing track 7" onto die ramp 12, which then gradually returns them to the height of the first track 7.

The tracks 7 in the network are recessed into the road 1, so they can be banked on curves without necessarily banking the road 1 as well. They may or may not require cross ties.

Figs. 1, 2, 3 and 4 each show only one track 7, though it is understood that the travel lanes in die network may have a plurality of these tracks 7 running in parallel so that vehicles may use more than one track 7 for stability.

*** THE WHEEL SYSTEM ***

To cooperate with the travel lane, vehicles will be provided with the wheel system shown in Fig. 5. The rolling-wheel subsystem will be comprised of at least one rolling wheel 14 that rides in the track(s) 7. The rolling wheel(s) 14 will be made of a material with low coefficients of friction and rolling resistance, e.g. steel. And the traction-wheel subsystem will be comprised of a plurality of traction wheels 15 that ride on the surface of the road 1. The traction wheels 15 will be made of a material with higher coefficients of friction and traction, e.g. rubber, and may be of the pneumatic type.

If the track(s) 7 are provided with the recess 8 at the bottom, the rolling wheel(s) 14 should have a corresponding indentation 16 around their circumference to prevent a ridge from forming after prolonged operation.

Vehicles built according to my specification will have their traction- wheel subsystems configured in such a way that, except for features hereafter described, is substantially similar to the manner of the traction- wheel systems of today's common road vehicles. That is, their traction wheels 15 will be securely and statically mounted to the chassis, preferably by way of a suspension system; their traction wheels 15 will be connected positively to a road-mode steering system; and at least one of their traction wheels 15 will receive power from the drive train.

Vehicles will use their traction- wheel subsystems to achieve traction with the flat road 1. This will allow them to drive safely in road mode, as well as switch tracks and efficiently accelerate, decelerate, and climb grades in track mode.

Vehicles built for travel on my travel lanes will not need to have their rolling-wheel subsystems connected to either a steering system or the drive train. However, the rolling-wheel subsystem must provide the rolling wheel(s) 14 securely attached in such a manner that they can be raised and lowered in relation to the chassis by a hydraulic system or other means during travel.

Vehicles will lower their rolling wheel(s) 14 into the track(s) 7 for track-mode operation. As they extend their rolling wheel(s), vehicles will be pushed up and away from the road 1 and their weight will gradually be shifted from their traction wheels 15 to their rolling wheel(s) 14. This will transition vehicles into track-mode travel where they will enjoy efficiency gains and track-bound, driverless operation. And as they retract their rolling wheel(s), vehicles will be lowered back onto the road 1 and their weight will gradually be shifted back to their traction wheels 15. Vehicles will be able to retract their rolling wheel(s) 14 far enough so as to fully clear both the track(s) 7 and the road 1; this will transition vehicles back to road-mode travel. The vehicles must be able to put their full weight onto their traction- wheel subsystem in order to achieve road-mode functionality and track-mode switching support. And while it is desirable that vehicles are also able to put their full weight onto their rolling-wheel subsystems for maximum efficiency gain, it is not essential.

Fig. 5 shows only one of each kind of wheel, though it is understood that vehicles may have a plurality of each of these wheels for stability. It should be noted that while vehicles will need more than one traction wheel 15 to drive safely while on the flat road 1 and while switching tracks, they need not have more than one rolling wheel 14 to follow and to shift weight onto the track(s) 7. The task of attaching such wheels and the corresponding hydraulic systems to vehicles will be well known to manufacturers.

What makes the rolling-wheel(s) operable is not the fact that they can be raised and lowered in relation to their vehicle, but that they can be raised and lowered in relation to the traction wheels. It is not the vehicle that provides the reference frame for how far away the road is, it is the other set of wheels that provides this reference. Thus it is conceivable that vehicles could be configured in reverse fashion - i.e. with their rolling-wheels 14 statically connected to the chassis and their traction- wheels 15 mounted to extend and retract - and the functionality would be identical.

The embodiment described in the above paragraphs is preferred over the reverse arrangement though, because it will be simpler to connect the traction wheels 15 to the drive train if they are not also required to extend and retract, and thus it will be cheaper to build and maintain.

Also, both wheel subsystems could conceivably be mounted to extend and retract in relation to their vehicles, but again, this would be inferior to the described embodiment because it would increase cost and complexity without adding significant functionality.

With the network's trough-shaped tracks 7, larger pieces of debris are a problem for passing vehicles, as they too will tend to get stuck in the potential-energy well. Fig. 6 shows one possible mechanism for dealing with an obstruction 17. The rolling wheel subsystem will be provided with a scoop 18 that travels in the track(s) 7 in front of the rolling wheel(s) 14 that will attempt to clear the track(s) 7. The scoop 18 will be able to retract if it fails, as shown in Fig. 7.

*** THE STEERING SYSTEM ***

When their rolling wheel(s) 14 are lowered into the track(s) 7, vehicles are constrained to operate in the potential-energy well created by the trough shape of the track(s) 7. Vehicles therefore do not require any special steering apparatus to stay in the travel lane and keep their rolling wheel(s) 14 properly aligned while traveling in track mode. The traction wheels 15, however, present a challenge. It will be advantageous if vehicles are able to use the same traction wheels 15 during both road-mode and track-mode travel, but the steering requirements for the two modes of travel differ significantly. While vehicles are in track mode, their traction wheels 15 must be kept pointed parallel to the track(s) 7 at all times, and the usual road-mode steering system will not be able to do this. Therefore, vehicles must be provided with a track-mode steering system in addition to the usual road-mode steering system.

To suitably steer the traction wheels 15 while in track mode, each traction wheel 15 must be mounted in such a manner that it can turn side-to-side about a substantially vertical axis, called the "pivot line." And each traction wheel 15 must be provided with a means to keep it pointed in the direction of travel, parallel to the track(s) 7.

Fig. 8 shows one embodiment of a suitable arrangement for the steering of the traction wheel 15. Vehicles will have the inner ball of a ball joint 19 securely connected to their chassis so they may distribute their weight to it. The traction wheel 15 is mounted on the outer socket of that ball joint 20. The ball joint 21 will allow the traction wheel 15 to turn side-to-side about its pivot line. The wheel 15 may be connected so as to receive power from the drive train 22. And connected to the outer socket of this ball joint 20 will be an actuator piston 23 that is capable of turning the wheel 15 side-to-side about its pivot line.

In this embodiment, a ball joint was selected for providing the wheel with side-to-side turning ability because it will find special use later on, but any of the more traditional wheel- mounting means may also, of course, be used in its stead when said special use is not needed.

This actuator piston 23 is suitable for track-mode steering, in that vehicles will be able to use it to steer the traction wheel 15 properly while on the track(s) 7. They can individually control me piston 23 of each traction wheel 15 to keep it pointed in the right direction at all times.

However, this would require some sophisticated sensing and control systems, and a simpler embodiment, if one can be found, will always be preferred because it will nearly always be cheaper. The simpler solution, in this case, is to utilize the caster angles of the traction wheels 15 to have them point themselves in the proper direction.

When vehicles are in track mode they are being guided by the track(s) 7, and the traction wheel subsystem is not needed for this purpose. So the track-mode steering system will not need to be a steering system, per se, but merely a means to keep the traction wheels 15 pointed in the right direction. The traction wheels 15 are not needed for guidance, so by giving each of them a positive caster angle while coasting or braking, vehicles can have their traction wheels 15 steer themselves when they are in contact with the road 1. And by switching any and all powered traction wheels 15 to a negative caster angle whenever they are being used for acceleration, their self-steering can be preserved. Vehicles able to manipulate the caster angle of their traction wheels 15 while traveling in track mode can then achieve track-mode wheel guidance by simply disconnecting their road-mode steering systems and letting the traction wheels 15 turn freely.

One embodiment of a device suitable for manipulating the caster angle of the powered traction wheels is shown in Fig. 9. It is the ball joint 21 on which the traction wheel 15 of the earlier embodiment was mounted. This joint will allow the wheel to turn side-to-side about its pivot line while the angle of that axis is being actively changed. Fig. 10 shows a cutaway view of the inside of this ball joint 20. Here, we can see two pins 24 extending from the outer socket 20 and protruding through slots in the inner ball 19 and into receptacles in a sleeve 25. These pins define the joint's pivot line 26. The sleeve 25 will extend out of the ball joint 21 where there is room for an actuating mechanism. By rotating the sleeve 25, the pins 24 are tilted forward and backward, changing the caster angle of the wheel 15.

Even though they are not the primary means for steering the traction wheels 15 during track-mode travel in this embodiment, the actuator pistons 23 are still required in order to switch from the road-mode steering system to the track-mode steering system and back.

The usual road-mode steering system has a very strict set of parameters; the traction wheels 15 are either fixed to point straight ahead at all times, or they are connected to a linkage system that turns them to very specific angles in relation to each other. Transitioning from the road-mode steering system to the track-mode steering system will require that the traction wheels 15 are freed of these constraints so that castering will be effective. And transitioning back to the road-mode steering system will require the traction wheels 15 to be restored to these constraints. The actuator pistons 23 accomplish this.

The actuator pistons 23 will be able to lock in the half-way extended position. While so locked, they form rigid connectors that can be incorporated in the road-mode steering system without significantly changing the parameters of that system. When the wheel 15 would be mounted fixedly pointed straight ahead, the wheel 15 will instead be mounted to turn side-to-side but be prevented from so turning by the rigid actuator piston 23. And when the wheel 15 would be connected to a linkage system, one of those links can be replaced with the rigid actuator piston 23 and the linkage system will still function as desired.

Then, when a switch to the track-mode steering system is appropriate, these actuator pistons 23 can be released so that they extend and retract from their half-way point freely. This will give the wheels 15 the freedom to follow the track(s) 7 as their caster angles are manipulated. And when a switch back to the road-mode steering system is appropriate, diese actuator pistons 23 will be able to apply power to bring themselves back to their half-way points, where they will lock and reconnect the road-mode steering system.

While the actuator pistons 23 are released, the steering wheel should be locked to point straight ahead. Thus, the base attachment points of all the actuator pistons 23 are fixed in relation to their vehicle and they can be used to turn the wheels 15 while in track mode, which is part of the track-switching operation.

*** OPERATION ***

Vehicles built according to my specification will be able to travel in a manner substantially similar to today's common road vehicles while in road mode. They will use their traction-wheel subsystems to steer themselves along a path on flat roads and also to propel themselves down their chosen path. They will drive over my travel lanes as though ύiey were normal roads. They go anywhere a normal car is reasonably expected to go.

In addition, these vehicles will be able to transition into track mode. In order to accomplish this, vehicles will first be driven to a suitable part of the network of travel lanes. In practice, this means any place where the track(s) 7 are substantially straight, where there are no diverging track(s) 7' and where there are no other track(s) 7 in the vicinity that vehicles could inadvertently find themselves in. Vehicles will then align themselves with the track(s) 7 and lower their rolling wheel(s) 14. They will lock their steering wheels straight ahead, release the actuator pistons 23 and set the caster angles of the traction wheels 15 to complete the transition to the track-mode steering system.

The order in which these operations are undertaken can vary, as the transition to track- mode can be undertaken with any of several degrees of sophistication. The least complicated method is where vehicles first lower their front rolling wheel(s) 14 and then drift slowly back and forth across the travel lane until the rolling wheel(s) 14 settle in the track(s) 7. They then release their front actuator pistons 23 and lock their steering wheels. If present, vehicles then lower their rear rolling wheel(s). After the rear rolling wheel(s) have followed the front rolling wheel(s) into the track(s) 7, the rear actuator pistons will be released and the transition is complete. Once a rolling wheel 14 has settled in the track 7, vehicles can shift weight to that wheel 14 by raising themselves with the hydraulic system.

Another, more sophisticated, method by which vehicles can make the transition is to first lock their steering wheels and release all of their actuator pistons 23. Then a computer will use the the actuator pistons 23 to steer the traction wheels 15 to guide the rolling wheel(s) 14 onto the track(s) 7, at which point they will be lowered.

Once vehicles have transitioned to track mode, they will distribute their weight between the wheel subsystems to increase efficiency. By raising and lowering their rolling wheel(s) 14, they shift weight from one wheel system to the other and back. So when vehicles are coasting and have little use for traction, they will shift their weight to their rolling wheel subsystems for minimum travel impedance. And when they need traction, for instance to accelerate or decelerate or climb steep grades, they will shift weight back onto their traction-wheel subsystems where it will generate the necessary traction.

Fig. 11 shows a cross-sectional view of the track splitter. In order to switch tracks while in track mode, vehicles will first put their full weight onto their traction wheels 15. Then they will lift their rolling wheel(s) 14 high enough so that they will clear the barrier 11, but not so high that they come out of the track(s) 7. Simultaneously, the actuator pistons 23 will slightly turn the wheels in the direction of the diverging track(s) 7'. This will generate a steering force in the direction of the diverging track(s) 7' and press the rolling wheel(s) 14 against the side wall 9 of the track(s) 7. Vehicles will then ride the side wall 9 of the splitter onto the diverging track(s) 7.

It is conceivable that vehicles could use their actuator pistons 23 to steer their traction wheels 15 to clear the barrier 11 without relying on the side wall 9 of the splitter for guidance, but this will increase the complexity of the operation.

If vehicles encounter obstructions 17 in the track(s) 7, the scoop 18 will attempt to throw them out of the track(s) 7 before they foul the rolling wheel(s) 14. However, if an obstruction 17 is too firmly lodged into the track(s) 7 to be thrown without causing damage, the scoop 18 will give way as shown in Fig. 7.

This event will cause a release of the hydraulic pressure keeping the rolling wheel(s) 14 extended. Vehicles will then fall safely onto their traction wheels 15, which will carry their weight on the surface of the road 1. The rolling wheel(s) 14 will continue to be held in the track(s) 7, but only with minimal force so that they will bounce over the obstruction 17 without major disruption. During this event, vehicles will preferably be held in the travel lane by the rolling wheel(s) 14 riding in a separate, parallel track 7. The traction-wheel subsystem will assist in guidance during this event, or it will take over guidance completely if there are no other rolling wheels 14 in a track 7. This is one reason that a plurality of parallel tracks 7 is desirable.

An alternative method of dealing with obstructions 17 is to use a detecting system that will detect them in the track(s) 7 and then signal to the hydraulic system to lift the rolling wheel(s) 14 over the obstruction.

And finally, when vehicles wish to leave the track network, they will simply raise their rolling wheel(s) 14 while die actuator pistons 23 bring die traction wheels 15 back into alignment for road-mode steering. The actuator pistons 23 will then lock and the steering wheel will delock and vehicles will continue on the flat road 1.

*** RAMIFICATIONS ***

This transportation system is quite clearly intended for use on conventional automobiles. Fig. 12 shows an example of how a four-wheel car would be converted. Adding the elements described herein will be a very straightforward operation, and existing vehicles can easily be converted to run on the new track system. This will revolutionize our roads.

What should also be clear is that other configurations of vehicle are possible. For instance, a one-seat-wide vehicle could be built to use the same gauge tracks as the full-size vehicle. It would mount its rubber wheels inside of the tracks, but it would operate identically.

Or a dual-mode vehicle could be manufactured to use only a single track. These would be able to run on a dual-track network as well as on single-track extensions which penetrate into smaller, more out-of-the-way places.

*** SCOPE ***

After the above disclosure, what should be apparent is that it is not really the flange on the rolling wheels that prevents dual-mode transit from being realized. The flange would be functionally equivalent to one of my rolling wheels that was lowered into its track, but was not supporting any weight. The tread of the flanged wheel would be equivalent to the traction wheels.

The real problem with the flange is not that the rolling wheels have one, it is that the vehicles that have such wheels are not able to lift their flanged wheels up and over to a diverging track. They lack this functionality because they do not have another wheel system to support themselves with during this operation. Therefore, the real heart of this disclosure is not either of the types of wheels, but the steering system that enables vehicles to switch their traction wheels from road-mode steering to track-mode steering and back again.

One of my vehicles using flanged rolling wheels would function nearly identically to what I have described. The rolling wheels 14 would simply distribute weight through the flanges 5 of the rails 3 while their (the wheel's) flanges would travel in the groove 7. Weight would be shifted back and forth from one wheel system to the other in the exact same manner, and entering and leaving the track would be an identical operation. Switching tracks would also be exactly the same, except that the flange is already partly lifted for purposes of clearing the barrier 11 by virtue of die fact that it was never traveling in the extreme bottom of the track 7 in the first place.