The invention relates to a transport system, in particular for persons, containers and cargo which can be transported on standard platforms.

In overland transport of people and goods an increasing number of bottlenecks are beginning to occur, these being the result of the fact that existing transport systems are reaching the limits of their capacity. Traffic jams on the road network are thus by now a familiar occurrence, not only during morning and evening rush hours, but also at other times of the day. Many people hereby spend considerably more time in their cars every day than might be expected on the basis of the distance travelled. In addition, the congestion problem makes it increasingly more difficult for goods transported by road to be delivered on time. Railway transport is seen by many as a logical alternative, although the capacity of the existing railway network and the existing railway stock is far from being sufficient to take over the role of road transport. The share of railways in the total passenger transport thus amounts at the moment to only five percent, so that even a doubling of the capacity, which is not a realistic assumption, would only be able to lighten road traffic to a limited extent. Transport over water could be an alternative, particularly in a country rich in water such as the Netherlands, but this is generally slow and therefore unsuitable for passenger transport or the transport of perishable products or valuable products.

Expansion of the road network does not provide a solution, at least not in the short term, because it entails extremely high investment and the decision-making process relating to such investments moreover takes a particularly long time due to public hearings and objection procedures. Nor for the same reasons can the capacity of the railway network be increased quickly. The invention therefore has for its object to provide an alternative transport system with which capacity problems of existing systems can be obviated in the relatively short term and at relatively low cost. It must be taken into consideration here that the costs of a transport system are determined mainly by the investments required for the construction, energy consumption, maintenance costs and personnel costs.

The invention now provides a transport system which comprises at least one track which is suspended at a distance above a ground surface along a determined route and along which a number of transport units are movable, wherein the transport units are each suspended from the track and each provided with their own drive.

By making use of a track suspended some height above the ground, the environmental impact is small. The environmental impact is in fact mainly visual. Great environmental advantages of the system are that it does not cut across fauna routes and the sound production is actively suppressed at the source. It is thus anticipated that the number of objection procedures will also be limited, so that the decision-making and construction can thus take place relatively quickly. In addition, a suspended track requires less investment than a track which is laid on a body of earth, partly because large parts of the track can be manufactured industrially, so at low cost and with high quality. A track situated some height above the ground will further not cut across already existing infrastructural works such as roads, railroads and waterways, but pass over them at a distance, whereby the construction can be realized in rapid and simple manner. Owing to the high position there is further no danger of the track being accessed by unauthorized persons.

In addition to cost advantages, suspending of the track along a determined route in the vicinity of existing infrastructure also provides the advantage of accessibility, for instance for maintenance and mobile services. The space taken up on the ground is small because the greater part of the transport system is situated a distance above the ground, if possible along or above existing traffic roads or waterways. The system does not hereby come into conflict with existing land use and existing infrastructure.

Because the transport units are provided with their own drive an efficient system is obtained, wherein the transport units can be moved along the track independently of each other. A structurally simple and robust transport system is obtained when the track comprises at least one profile beam and each transport unit comprises at least one carriage with a number of wheels engaging on the profile beam and a load carrier suspended from the at least one carriage. A strong, rigid but nevertheless light construction is obtained when the at least one profile beam has a substantially I-shaped section. This is of great importance for limiting as far as possible the bending during passage of transport units or the lateral deformation as a result of wind load. An I -shaped profile beam also provides the option of a safe suspension and guiding of the transport units .

An upper flange of the I -shaped profile beam preferably protrudes in transverse direction outside a lower flange thereof and carries hanging wall parts close to its ends. The upper flange, the walls and the lower flange thus form a tunnel closed substantially on all sides which protects the suspension and drive of the transport units against ambient influences . A very efficient construction is obtained when at least the flanges of the I -shaped profile beam form box constructions built up of metal plate.

In order to ensure a stable and reliable suspension of the transport units, the at least one carriage preferably comprises at least two sets of runner wheels placed at a mutual distance in the transport direction and rotatable about lying axes, and at least one set of pressing wheels rotatable about upright axes . At least some of the runner and/or pressing wheels can here be drivable for the purpose of autonomous movement of the transport unit along the track. A compact, light and efficient construction is obtained when the drivable wheels are each connected drivably to an electric motor. The transport system according to the invention is preferably provided with control means which are connected to the drives of the transport units and which are adapted to maintain a substantially constant interspace between successive transport units. A "virtual cable" is thus as it were formed between the transport units which extends from the one end of the track to the other end, and back again from there over the other track. Despite having their own drive, the transport units hereby move along the track in the manner of cars of a cable railway. The transport capacity of the system can thus be maximized without the risk of collisions between successive transport units.

The control means can here comprise a number of sensors arranged along the track for detecting the presence of transport units at determined points along the track, although instead or in addition the control means can also comprise distance measuring means arranged in each transport unit for detecting the distance between the transport unit and a preceding or following transport unit. The transport system according to the invention can advantageously be further provided with a number of points, which each have a through- track segment and a branch segment, and with which transport units can be guided from the track to another track. Tracks along different routes can thus be connected to each other to form a network, while buffers or overtaking options can thus also be created in the system. The mutual distance and frequency of the transport units can hereby be adapted to the transport flow, hereby achieving a high degree of efficiency. The points can herein be slidable substantially transversely of the track or pivotable about an upright axis between a neutral position, in which their through-track segment forms part of the track, and a branch position in which their branch segment connects to the track. The transport system is preferably also provided with means for reversing the direction of movement of the transport units. The transport units can thus be moved reciprocally along the track, whereby a higher frequency can be achieved, particularly on shorter parts of the route. Although it is possible to envisage the direction of the drive of the transport units simply being reversed, whereby they travel back along the same track, it is recommended that the reversing means comprise a rotatable unit which connects two tracks to each other. The transport units can thus be transferred from an outgoing to a return track in the manner of a cable railway, whereby the concept of the "virtual cable" with the associated transport capacity is maintained.

The points and/or the reversing means are advantageously arranged in the track at the position of stations, where at least one platform is formed in each case for unloading and/or loading the transport units . The transport units can thus be diverted from the through- track at stations, so that the time necessary for loading or unloading does not affect the speed of the transport units moved over the through-track. In order to minimize this loading and/or unloading time the at least one platform can be movable in the transport direction.

In order to prevent deformation of the track as a result of temperature differences and/or displacements in the ground surface, the transport system according to the invention is preferably provided with expansion joints incorporated in the track at regular intervals .

In order to ensure the continuity of the track here, each expansion joint is advantageously bridged by a set of mutually engaging, strip- like finger segments slidable relative to each other. A stable connection and a smooth transition are thus formed between the parts of the track on either side of the expansion joint. This is of great importance in the light of the high speeds at which the transport units pass over the expansion joint.

A structurally simple and robust transport system is obtained when the track is constructed from a number of segments which are suspended from a number of portals, between which extend arched support constructions connected to the track.

Owing to these arched support constructions loads on the track resulting from the passage of transport units are transmitted in efficient manner to the portals, which are anchored in the ground. In order to prevent deformation of the track in efficient manner here, the expansion joints are preferably formed in each case between two portals, and the arched support constructions are connected at least partially for pivoting to the track. Owing to this partially pivotable suspension the support constructions can follow the displacements of the track at the expansion joints.

The segments of the track, the portals and/or the arched support constructions are preferably produced at a location remote from the route and assembled along the route. The track can thus be produced in industrial manner, so at high speed, at relatively low cost and with great precision. The operations at the route site then remain limited to relatively simple installation work which entails little disruption and can be performed quickly.

In order to make the best possible use of the space which must be kept clear for the track, the transport system according to the invention is preferably further provided with a traffic road arranged above the track. The route can thus be used for transport by means of transport units suspended from the track as well as for transport by means of conventional motor vehicles .

In order to limit the weight of the track, and thereby the load on the ground, as much as possible, the traffic road can then comprise a metal road surface with a plastic cover layer. Finally, the invention also relates to track segments, portals, arched support constructions and transport units, all evidently intended for application in a transport system as described above.

The invention is elucidated hereinbelow on the basis of a number of examples, wherein reference is made to the accompanying drawing, in which corresponding components are designated with reference numerals increased by 100, and in which:

Fig. 1 is a schematic perspective view of the transport system according to the invention,

Fig. 2 is a perspective bottom view of the transport system of fig. 1, Fig. 3 is a cross-sectional side view of a part of the track of the transport system of fig. 1 and 2,

Fig. 4A, 4B and 4C are detailed side views on enlarged scale as according to arrows A, B and C in fig. 3, Fig. 5 is a cross -sectional front view of an alternative embodiment of the transport system,

Fig. 6 shows a partially cross-sectional side view of the profile beam of the transport system of fig. 5, Fig. 7A and 7B show cross-sections on larger scale of the profile beam of fig. 5, wherein fig. 7A is a cross-section at the position of the pressing wheels and fig. 7B at the position of the runner wheels of a transport unit,

Fig. 8 is a perspective front view of a transport unit of the system, formed by a passenger compartment suspended from the track via carriages,

Fig. 9 is a schematic top view of a pivotable single point for application in the transport system,

Fig. 10 is a view corresponding to fig. 9 of a pivotable three-way point,

Fig. 11 is a view corresponding to fig. 9 and 10 of a slidable point,

Fig. 12A, 12B, 12C and 12D show schematic top views of different possible embodiments of stations along the track, Fig. 13 is a cross-sectional top view of a rotatable unit for reversing transport units,

Fig. 14 shows a perspective view of the carriages with runner wheels and pressing rollers from which the passenger compartment is suspended, Fig. 15 is a top view of an expansion joint with associated bridging, and

Fig. 16A and 16B are side views of the expansion joint with bridging in respectively the connected and the opened position. In the shown example a transport system 1 according to the invention comprises two tracks 2, 3 which run along a determined route and are suspended at a distance h above a ground surface G (fig. 1) . These tracks 2, 3 are mutually connected at their end points and thus form an outgoing and a return route . Transport units 4 , each suspended from one of the tracks 2 , 3 and each provided with their own drive, are movable along these tracks 2, 3. Tracks 2, 3 are suspended from portals 5, which are placed on the ground surface G at regular intervals, for instance 60 m. Arched support constructions 6 connected to tracks 2, 3 extend between these portals 5. The connections between the different components are partly welded connections and partly bolt connections. Portals 5 are mounted on concrete foundations 62, which, if necessary, are pile-supported. The whole construction is embodied such that readjustments in height, length and/or width are possible if settlement or subsidence in the foundation makes this necessary. The height of the construction is chosen in the shown example such that under normal circumstances the free height under transport units 4 amounts to 4.50 m. This height can however be adapted to local conditions, for instance at water crossings, junctions with elevated roads or tracks, or in built-up areas. Each track 2, 3 comprises a profile beam 7 and in the shown example each transport unit 4 comprises two carriages 8A, 8B, which together carry a load carrier 9 (fig. 14) . This load carrier 9 can comprise a passenger compartment, although it is also possible to envisage for instance containers being suspended from carriages 8, or platforms on which freight is transported, such as passenger cars or trucks. The front carriage 8A here has two sets of runner wheels 10 which are placed at a mutual distance in the transport direction and which are rotatable about lying axes 11, while the rear carriage 8B has a single set of runner wheels 10. Transport unit 4 thus has a total of six runner wheels 10 here. It is also possible to envisage more or fewer runner wheels being used, depending on the weight of transport unit 4. The runner wheels could also be divided over more than two carriages. At least two sets of wheels, so four runner wheels, must be present for stable running.

In addition, each carriage has a double set of pressing wheels 12 rotatable about upright axes 13. Runner wheels 10 here transfer the weight of transport unit 4 to profile beam 7, while pressing wheels 12 serve to hold transport unit 4 in engagement with profile beam 7 under all conditions, so also in bends. Pressing wheels 12 can be provided for this purpose with pneumatic tyres or running surfaces covered with a plastic, for instance polyurethane, whereby some flexibility and bias can be realized on the vertical parts of profile beam 7. If desired or necessary, this effect can be enhanced by hydraulic or air cylinders 14. Runner wheels 10 can also be provided with pneumatic tyres or running surfaces covered with plastic in order to increase travel comfort.

Finally, front carriage 8A is also provided with a set of guide rollers 67 protruding in front of front runner wheels 10, whereby carriage 8A is guided in bends.

Because runner wheels 10 and pressing wheels 12 are mounted on carriage 8 per set, all loads exerted by wheels 10, 12 are symmetrical and compensate each other where possible. The wheel supports must here be connected to each other for horizontal and vertical pivoting.

At least some of the runner wheels 10 and/or pressing wheels 12 can be driven. For this purpose the driven wheels, in the shown example all runner wheels 10, can each be connected for driving to an electric motor 17. These electric motors 17 are powered by one or more power lines 16 laid along tracks 2, 3. In the shown example these electric motors 17 are built into the runner wheels 10 driven thereby. A compact and light driving is hereby obtained which can produce a high power. This arrangement in particular leaves space clear between runner wheels 10, this being particularly important when an I-shaped profile beam 7 is used as track. The electric motors can otherwise also be placed in lengthwise direction between the sets of wheels, and then drive runner wheels 10 via cardan shafts and right-angled transmissions. Pressing wheels 12 are not driven in this example.

The two carriages 8 are mutually connected for pivoting about an upright axis by a hinge (not shown here) with built-in damper, whereby the relatively long transport unit 4 will also follow track 2, 3 well in bends. Load carrier 9 is suspended from the two carriages 8A, 8B by means of protruding parts 15 of support arms 65 of pressing rollers 12 (fig. 7) . Dampers can here also be provided between the top side of load carrier 9 and the underside of each carriage 8. The suspension of load carrier 9 can take a pivotable form to allow it to swing outward slightly in bends, which can be comfortable for travellers and can additionally result in a lower tilting moment on carriages 8. Because the gravitational force on the hanging load carrier 9 counteracts the centrifugal force, transport unit 4 can travel through bends at relatively high speeds in stable manner.

In the shown example profile beam 7 has an I-shaped cross-section with a central web plate 22 on which pressing wheels 12 engage from either side, two outward protruding lower flanges 21 over which runner wheels 10 can roll and two outward protruding upper flanges 63 (fig. 7) . The pressing wheels are otherwise embodied slightly differently here than is shown in fig. 8 and 14. In order to protect the rotating parts of carriages 8 against outside influences such as icing, snow, sand, flooding or falling leaves, two non-bearing outer walls 23 are here connected to the upper flanges 63 of I-shaped profile beam 7 which protrude outside lower flanges 21. A tunnel closed substantially on all sides is hereby formed. Defined between outer walls 23 and the ends of lower flanges 21 are relatively narrow gaps through which protrude the support arms 64, 65 of respectively runner wheels 10 and pressing wheels 12 of carriages 8. Outer walls 23 consist of light, profiled plate material in the form of removable panels, whereby monitoring and maintenance of the route and the equipment arranged thereon is possible in simple manner .

By making use of I-shaped profile beams 7, both flanges 21, 63 of which have not only a supporting function but also an additional function - protection for the upper flange and guiding and support for lower flange 21 - a highly efficient construction is obtained. In addition, I-shaped profile beam 7 is inherently safer than the reverse U-shaped profile which has been applied in some conventional transport systems. If one or more wheels 10, 12 were to break off a transport unit 4, it would on the one hand always remain suspended on lower flange 21 of I-shaped profile beam 7. In addition, an I-shaped profile, in contrast to a reverse U-shaped profile, does not entail the danger of outward bending under load, whereby the integrity of the suspension would also be adversely affected. Upper and lower flanges 63, 21 of each I-shaped profile beam 7 are constructed here as box constructions, consisting of a number of external and internal metal plate parts 66 mutually connected by means of welding, glueing, riveting or in other manner. Relatively large segments of profile beam 7 can be produced by making use of plate material. In the shown example web plate 22 is formed by a lattice construction which, in any case at the position of pressing wheels 12, is covered with plate material or is provided there with a rail.

Owing to this construction of I-shaped profile beam 7 a strong and rigid construction is obtained which is still relatively light. The strength and rigidity are such that the bending of beam 7 during passage of a transport unit 4 and the lateral deformation as a result of wind load are no more than a few millimetres. This is important in respect of the high speeds at which the transport units move along the track. When plate material 66 with a thickness of 8-10 mm is for instance used therefor, the mass of profile beam 7 can remain limited to about 700 kg/m. Beam 7 can for instance be produced in segments with a length of 60 m, which segments then have a mass of over 40 tons, which can be readily handled with suitable equipment.

The upper side of profile beam 7 could otherwise be covered with solar panels, whereby at least part of the energy requirement of transport system 1 can be provided.

Transport system 1 is further provided with control means 18 which are connected operatively to electric motors 17. These control means 18 are adapted to maintain a constant interspace between successive transport units 4. The value of this interspace can be made dependent on the desired transport capacity.

Use is made in the shown example of a minimal interspace of thirty seconds at the maximum capacity, i.e. during rush hours. When each load carrier 9 comprises a passenger compartment for forty travellers, this results in a maximum transport capacity of 4800 passengers per hour. Use is further made of a cruising speed of transport units 4 of about 60 m/s, so over 200 km/h, whereby the interspace amounts to at least 1800 metres. Control means 18 act in each case to de-energize at least a part of the power line(s) corresponding to this interspace behind each transport unit 4. In practice only those segments of the track where transport units 4 are present at a determined moment and the segments immediately following need be supplied with power, while the rest of the track can remain de-energized. Because control means 18 thus maintain a constant interspace between the transport units, it is as if they are fixed to a "virtual cable", and transport system 1 thus functions in the manner of a cable railway. During off-peak hours, when the traffic flow is limited, the frequency can be reduced and the interspace increased, whereby some of the transport units 4 can be removed from the route. Operating costs are thus limited, and a considerable return can then also be achieved. Waiting times for travellers are even then still much shorter than is usual in the case of conventional transport systems such as bus and train.

Control means 18 receive signals from a number of sensors 19 arranged along each track 2, 3 (fig. 3) which detect the presence and speed of passing transport units 4. In addition, control means 18 receive signals from sensors arranged in each transport unit 4. These can be distance measuring means 20, for instance on the basis of radar or laser, which detect the distance from a relevant transport unit 4 to a preceding or following transport unit, but also sensors which determine the acceleration of transport unit 4. Other methods of determining position and distance can however also be envisaged. Transport units 4 could thus each be provided with a GPS system, with which the position along track 2, 3 could be determined and passed on to control means 18.

Transport system 1 according to the invention is further provided with a number of points 24, with which transport units 4 can be guided from the track along which they are moving to another track, for instance a side track 25. Each point 24 has a through- track segment 26 and at least one branch segment 27 (fig. 9) . In the three-way point 124 shown in fig. 10 there are even two branch segments 127a, 127b. Points 24 and 124 shown in fig. 9 and 10 comprise a pivotable element 29; 129 in which through-track segment 26; 126 and the or each branch segment 27; 127a, 127b are formed. This element 29; 129 is pivotable around an upright axis (transversely of the plane of the drawing) between a neutral position, in which its through-track segment 26; 126 forms part of the track, and a branch position in which respectively its branch segment 27 or one of its branch segments 127a, 127b connects to the track. For the sake of clarity fig. 10 otherwise does not show all possible positions of through-track segment 126. In an alternative embodiment each point 224 is slidable transversely of the track between the neutral position and the branch position (fig. 11) . Point 224 can here be displaced by means of chains, driven wheels or cylinders with synchronizing provisions. Fixing in respectively the neutral position and the branch position is controlled by electrically or hydraulically driven stops and jaws. Switching on and off of the electric power supply to carriages 8 is controlled simultaneously with the fixing by means of switching systems.

Both the horizontally displaceable point 224 and the pivotable points 24, 124 can be movable over rails or slide tracks, which are suspended from a construction situated thereabove. The driving of the points can take place electrically or hydraulically. Hydraulic driving is recommended in the case of power failure. The energy stored in hydraulic accumulators can be sufficient to power an additional number of movements provided the control and hydraulic control valves are operated via emergency power accumulators .

Points 24; 124; 224 can otherwise be provided with sensors or switches which determine and transmit the position of point 24; 124; 224 to control means 18. Transport units 4 can hereby be prevented form switching tracks unintentionally, and the speed of a transport unit 4 can be adjusted to the approach of a point 24; 124; 224. The safety of transport system 1 is thus increased. Points 24; 124; 224 can be relatively short, in the order of 0.8 - Im, since they turn the track in only one direction toward side track 25; 125; 225. The further branching, for instance to a direction in which side track 25; 125; 225 once again runs parallel to the main track, takes place in the fixed part of side track 25; 125; 225, as can be seen in fig. 12C. Points 24; 124; 224 can therefore take a relatively light form and can be operated quickly and easily. In addition, transport system 1 can be provided with means 28 for reversing the direction of movement of transport units 4. This can be important in being able to achieve a higher frequency of the transport units on a relatively short route segment. In their simplest form, control means 18 can be adapted to control the electric motors 17 of all transport units 4 such that transport units 4 begin to move in a direction opposite to that in which they were moving up to that moment. A reciprocal movement along a single track can thus be achieved.

When however transport system 1 comprises two tracks 2 , 3 as in the shown example, reversing means 28 can take the form of a rotatable unit 29 which mutually connects the two tracks 2, 3 (fig. 12D) . This unit 29 comprises here a square frame 30 from which two segments 31, 32 of tracks 2, 3 are suspended (fig. 13) . Frame 30 is mounted via a number of rollers 33 for rotation on a ring 34 fixed above tracks 2, 3. Unit 29 is rotated 180 degrees at a time by two pinions 35 which are placed diametrically opposite each other and which engage in a rotatably driven toothed wheel 36. Lateral forces on toothed wheel 36 and its bearing are thus prevented. Unit 29 is fixed in each of its two end positions, in which track segments 31, 32 lie precisely in line with one of the tracks 2, 3, by means of locking elements 37 which are movable between a releasing position and a locking position. Carriages 8 suspended from track segments 31, 32 are braked during the rotation. The necessary electrical provisions are switched on and off automatically during the rotation and after the fixing. In yet another embodiment reversing means 128 can take the form of a substantially circular loop connecting the two tracks 102, 103 to each other (fig. 12A) .

Although points 24, 124 can be arranged anywhere two tracks connect to each other, for instance to guide single branches as bypasses through urban areas or other centres with heavy traffic flow and then reconnect them to the main line, most points 24, 124 and reversing means 28, 128 will be arranged in tracks 2, 3; 102, 103 at the location of stations 38, 138 (fig. 12A- 12D) . Slow trains can thus for instance be sidetracked at stations 38, 138 located between the end points of the line and be reintroduced into the outgoing or return line, whereby short circuits are possible. In addition, transport units 4, 104 can be guided at these stations 38, 138 onto a low- speed route, where they can be unloaded and/or loaded.

Formed on either side of tracks 2, 3; 102, 103 at stations 30, 138 are platforms 39, 139 which serve for unloading and/or loading of transport units 4, 104. These can be conventional platforms as already applied at train stations, tram and metro stops, but it is also possible to envisage platforms 39 being movable in the transport direction (fig. 12B) . Unloading and/or loading of transport units 4, in particular disembarkation and boarding of passengers, can hereby take place while transport units 4 continue to move forward at low speed. Transport unit 4 need not therefore be brought to a complete standstill, which saves time and energy. This is also made possible in that each transport unit carries only a relatively limited number of passengers, so that short boarding and disembarkation times can be achieved. Because the passenger flow is substantially constant as a result of the constant interval between successive, relatively small transport units 4, stations 38 do not need to be designed for any type of rush hour crowding, but have to be able to process a more or less constant flow of passengers. Stations 38 can hereby be built smaller, more simply and thus at lower cost than conventional railway stations.

Fig. 12A shows a terminal station or end station where tracks 102, 103 converge. This station has reversing means 128 in the form of a large loop on which a plurality of transport units 104 can be parked for routine maintenance. During rush hour one transport unit 104 enters and one must leave every 30 seconds. Transport units 104 then keep moving through the loop at a low speed. During the night and at times with little traffic flow, they remain on the loop longer. Platforms 138 are provided before and after the loop to allow boarding and disembarkation of passengers or maintenance staff.

Fig. 12D shows another possible embodiment of a terminal station or end station 38, with reversing means 28 in the form of a rotatable unit 29. Platforms 38 are likewise arranged before and after rotatable unit 29. This type of station can also be a regular station in the case that the through- track requires less transport capacity and only a limited number of transport units pass through. Station 38 can also provide a connection to sidings, unloading locations for containers or repair workshops .

Fig. 12B shows a station 38 incorporated in through-tracks 2, 3. Return transport units 4 are here braked by control means 18 to a speed of for instance 2 m/s or less before station 38 and are automatically kept at a safe distance of for instance 1 metre from the preceding unit 4. At such a station 38 at least six transport units 4 at a time can for instance travel one behind the other at a low speed of 2 m/s or less. When the leading transport unit 4 departs, it can if desired be accelerated by linear motors. In this embodiment use is made of the above described co-displacing platforms 38. This system could also be embodied in a part of a circle, wherein moving platform 38 would then be rotating, with an inner circle which would have a lower peripheral speed.

Fig. 12C also shows a station 238 which is incorporated in through- tracks 202, 203. This station 238 is provided with horizontally moving points 224 with which it is possible to travel on and off a side track. Through transport units 204 can pass through this station 238 when points 224 are in the correct position. This point system can also be used to hook on or unhook containers or freight platforms. If possible, stations 38, 138 are otherwise planned above so-called park and ride areas, where passengers can transfer directly to their own car. Placing above stations of other transport systems, for instance bus stations, metro stations, tram stops or train stations, can also be envisaged. Travellers can thus change means of transport easily. Platforms 38, 138 will be placed at a height of several metres above the ground and can be reached by means of escalators, stairs and lifts.

Because tracks 2, 3 will expand and shrink as a result of temperature differences, expansion joints 40 are incorporated therein at regular intervals. Assuming maximum temperatures (with the influence of insolation) in the order of 60 degrees Celsius and minimum temperatures of -40 degrees, the maximum displacement at the position of joint 40 will be in the order of 6 cm in track segments with a length of for instance sixty metres (fig. 16A, 16B) .

In order to prevent runner wheels 10 hereby travelling through a "hole" at low temperatures, when expansion joints 40 are open, each expansion joint 40 is bridged in the shown example. The bridging is formed here by a set of strip- like finger segments 41, 42 which mutually engage and are slidable relative to each other (fig. 15) . These finger segments 41, 42 are alternately connected with an end 43 , 44 to one of the track segments on either side of joint 40. This connection can for instance be formed by a pin 45. A spacer 46 is arranged in each case between two mutually- adjacent finger segments 41, 42 on one of the two sides, whereby an intermediate space is created for the finger segment 42, 41 protruding therebetween from the other side of joint 40.

Finger segments 41, 42 are received in separate housings 47, 48, which are carefully fixed in lower flanges 21 of profile beams 7 so that the upper sides of finger segments 41, 42 lie precisely flush with these lower flanges 21 over which runner wheels 10 move. Cuts are made in finger segments 41, 42 over a part of their length corresponding roughly to the maximum displacement on the upper side. The cut parts 49, 50 fall beneath cover plates 51, 52, which prevent finger segments 41, 42 from moving upward in the engaging situation and disrupting a smooth transition. Cover plates 51, 52 are further chamfered at the position of engaging finger segments 41, 42 in order to prevent dust and dirt penetrating thereunder.

The vertical parts of profile beam 7, along which pressing wheels 12 move, are otherwise cut slantwise at the position of expansion joint 40 and take an overlapping form, whereby a continuous surface for pressing wheels 12 is still created.

A tensile stress can further be realized on the top side of each track segment at the position of expansion joint 40 by hydraulic cylinders on the following track segment. A compression stress can be realized on lower flanges 21 by hydraulic cylinders. If the pressure lines are connected to each other the forces remain equal when the length of the track segments changes. The connection then functions as a continuous or a clamped sleeper and can thereby have a lighter construction. In the shown examples expansion joints 40 are formed in each case between two portals 5. In order to compensate the relative displacements of the track segments resulting from shrinkage and expansion, the arched support constructions 6 are here connected for at least partial pivoting to track 2, 3. In the shown embodiment support construction 6 is connected to tracks 2, 3 between two portals 5 at four locations 53, 54, 55, 56 (fig. 3) , the two middle connections 54, 55 of which are fixed and the two outer connections 53, 56 of which are pivotable in the longitudinal direction of tracks 2, 3. In addition, portals 5 are themselves pivotally connected to tracks 2, 3.

Fixed connections 54, 55 are formed by fixing a mounting 57, which is mounted on track 2 or 3 , to a bracket 59 using bolts 58 (fig. 4B) , which bracket extends over both tracks 2, 3 and which is mounted on the arched support construction 6. The fixed points in the two tracks 2, 3 are further connected to each other by a transverse connection in order to bring about greater rigidity in transverse direction of the support. The pivotable connection between portal 5 and tracks 2, 3 is situated at the position of expansion joint 40 and forms a double hinge. Bracket 59 here takes a separated form and comprises two steel plates 60, for instance of spring steel, which are each fixed with one end to a mounting 57 on one of the track segments and with their other end 61 to each other (fig. 4A) . These steel plates 60 are very rigid in their plane, thereby preventing movement in width direction. Pivotable connections 53, 56, which do not coincide with an expansion joint 40 form in each case a single hinge. A metal plate 60 is here fixed on one side to a mounting 57 by bolts 58 and is rigidly connected on the other side to bracket 59. The part of plate 60 extending between mounting 57 and bracket 59 can bend and thus forms the hinge. As stated, the segments of tracks 2 , 3 as well as portals 5, the arched support constructions 6 and other components of transport system 1 can be produced at a location remote from the route and be assembled along the route. The components can thus be produced industrially, and supplied fully finished, i.e. cabled, preserved and the like. At the route site only ready-made modules need be assembled, wherein possible use can be made of rapid-action couplings or plugs and sockets for connecting through- lines . This results in the first place in a better quality, because the production of the standardized modules can be automated to a great extent, while environmental influences will not affect the quality of the finished work. The continuous, weather- independent production results in a high production rate, whereby the production costs will be low. There is moreover minor disruption on the construction site along the route, since only assembly operations need take place there. A further advantage is that the prefabricated components can be supplied via already mounted parts of the track, thereby limiting disruption still further. Use can be made for this purpose of a specially designed support frame, with which continuous assembly can be realized.

Although transport system 1 according to the invention per se already provides a great improvement in the use of existing routes for intensive transport, the transport capacity of the system can be increased even further when a traffic road (not shown here) is constructed above the tracks.

For this purpose the overall construction must then of course be reinforced. In the examples shown above use was made of transport units 4 with a mass of 8000 kg, and the construction was therefore designed for a maximum load of 16000 kg (when two transport units 4 passing in opposite directions) . In this embodiment use is made of a four- lane motorway accessible only to light traffic (motorbikes and passenger cars up to 2000 kg and of limited dimensions) . The lanes are bounded by crash barriers. The traffic road can have a metal road surface with a plastic cover layer, and so have a limited own weight. Also necessary of course in addition to structural measures are further provisions are such as slip roads and exits, possible signalling or traffic guidance systems and the like. In addition, provisions must be made to enable rapid clearing of the lanes in the case of breakdown or accidents. It is possible here to envisage travelling overhead cranes which can move and lower stationary vehicles at positions on the ground intended for this purpose adjacently of the traffic roads.

The addition of the traffic road, which is only accessible to light traffic, relieves the existing infrastructure. An effective separation between fast (light) traffic and slow (heavy) traffic is thus also implemented, whereby the flow is enhanced and the forming of traffic jams is limited.

Because the traffic road, just as the other parts of the transport system, can be produced industrially, provisions can easily be incorporated therein for automatic traffic guidance. It is possible here to envisage signalling of optimal speeds and mutual distances, but also automatic control of speed and distance and programming of lane changes at slip roads and exits.

The invention thus provides a transport system which is quick and safe, has a high transport capacity, can be built and operated at relatively low cost and causes little disruption or pollution. Although the invention is described above on the basis of a number of embodiments, it will be apparent that it is not limited thereto but can be modified or varied in many ways. Instead of portals and arched support constructions, other constructions could thus also be applied for suspension of tracks 2, 3, particularly when specific circumstances make this necessary. Suspension constructions with guys could thus for instance be used, with special provisions for withstanding transverse forces resulting from wind load. The scope of the invention is therefore defined solely by the following claims.