EP2608183A2

EP2608183A2 - Vehicle detection loop for a road

Info

Publication number: EP2608183A2
Application number: EP13000008.6A
Authority: EP
Inventors: Hendrik Antoine Hoeflake; Egidius Johannes Antonius Heijmans; Johannes Pieter Cornelis FLEUREN
Original assignee: Traffiss BV
Current assignee: Traffiss BV
Priority date: 2011-12-23
Filing date: 2013-01-02
Publication date: 2013-06-26
Also published as: NL1039813C2; EP2608183A3

Abstract

Vehicle detection device to be accommodated in a road surface, comprising a cable having an electric conductor and a carrier that can be bent out of its plane at least in one direction, particularly a carrier that can be rolled up, wherein the carrier is grid-shaped having elongated grid elements that in between them define grid meshes, wherein the cable is attached in advance in the desired loop shape on the grid elements of the carrier.

Description

BACKGROUND OF THE INVENTION

The invention relates to a detection loop for a road surface, particularly an asphalt road surface, comprising a carrier with a cable attached thereto in a loop shape, the cable having one or more electric conductors.
Such detection loops are generally known and are used for recording the presence of vehicles driving over such loops. The disruption of the electromagnetic field of the detection loop caused by the passing vehicles can for instance also be used for controlling traffic lights, setting speed limits on variable message signs (VMS) and operating automatic traffic gateways and the like.
Detection loops are generally disposed after the top layer of the asphalt road surface has been laid and has cooled off sufficiently. For that purpose slits are milled into the asphalt into which the cables are laid, which slits are subsequently filled with bitumen. This method is very time-consuming and detrimental to the quality of the asphalt. For these reasons methods were looked for to manufacture the detection loops in advance and attach them to the sub layer of the asphalt prior to the top layer being applied.
From WO00/75906 an electromagnetic traffic signal detection system is known, having one or more detection loops comprising a pre-shaped electrically conducting material in one or more loops of a predetermined shape. For installation in a road surface an assembly of a geotextile base bandage impregnated with bitumen and having electric conductors secured thereon by a protective tape is placed on a layer (road pavement base) of the road surface. The assembly is secured to the layer of the road surface by means of a bituminous strip. After that a bitumen surface layer is applied. It is indicated that this method can be used at temperatures over 100°C, but temperatures below 80°C are preferred.
Said known detection loop, that has never actually been used on a large scale, has a number of drawbacks. First of all it requires a lot of work as the loop consisting of carrier and cables has to be laid in the correct position and shape, and subsequently has to be secured to the basis by means of the bituminous strip that is applied over the loop. Subsequently this method cannot be used with modern asphalt pavers that work with temperatures of 160-200°C and pressures of 20 tons and more. The sharp-edged material of the asphalt and the high dynamic loads that arise in applying the asphalt place particular demands on the protection of the cables, all the more as the caterpillar tracks of the asphalting machine exert large tensile forces on the cables.
From DE 10 327 332 a prefab assembly is known of a netting and a detection loop attached thereto. The assembly of netting and loop is attached to the foundation layer, for instance by means of a binder or by attachment elements extending in attachment holes in the netting. When laying a new road an intermediate layer (Binderschicht) and then a covering layer is applied over it. The number of loops on the netting can be chosen.
In this case as well the heat and the forces that arise during applying an asphalt layer over the loop may result in damage to the conductor and deformation of the loop.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a vehicle detection device that can be arranged quickly and easily.
It is an object of the invention to provide a vehicle detection device having a detection loop that can easily be laid in the correct shape.
It is an object of the invention to provide a vehicle detection device having a detection loop that can reliably be held in the correct shape during transport and during laying.
It is an object of the invention to provide an arrangement of a road surface having a vehicle detection device incorporated therein wherein a reliable induction signal is obtained.
It is an object of the invention to provide a method with which a detection loop can reliably and easily be incorporated in an asphalt paving.
For achieving at least one of these objects, according to one aspect, the invention provides a vehicle detection device to be accommodated in a road surface, comprising a cable having at least one electric conductor and a carrier, wherein the carrier is grid-shaped having elongated grid elements that in between them define grid meshes, wherein the cable is attached in advance in the desired loop shape on the grid elements of the carrier, wherein the carrier preferably can be rolled up at least in one direction.
The cable can be attached to the carrier in advance in an easy and controlled manner in the desired configuration in protective surroundings, a plant. The grid-shaped carrier offers sufficient discrete locations to attach the cable including conductor(s) in the desired configuration. In the preferred embodiment the assembly can subsequently be rolled up into a compact unit, with the cable on the concave side, and be stored and transported in said condition that takes up little space. The detection loop is then protected in the roll. When being placed in the work the grid-shaped carrier, due to the meshes, further ensures an intense engagement with the road surface layer to be applied thereon.
In order to prevent that the electric insulation of the conductor gets damaged as a result of the high temperatures of hot asphalt and the possibility of short-circuiting, the cable preferably comprises a heat-resistant insulation. In one embodiment the electric conductor has a number of singular wires each provided with a heat-resistant insulation, particularly a heat-resistant coating, particularly lacquer (as known per se from singular wires in a coil of a transformer), and together form the conductor in the form of a core/litze wire. In that way a reliable insulation that is resistant to high temperatures is provided as a whole for the conductor, in the form of a core/litze wire, preserving sufficient suppleness of the core/litze wire and thus the cable for laying it in the desired shape and rolling it up. In fact the smallest conductive element of the cable, the singular wire is provided with a heat-insulating sheath. The thus coated wires can be stranded into the core/litze wire.
It is noted that in WO 99/47894 a detection loop is shown having a cable having a number of multiple-wired or solid (in order to increase the rigidity) conductors. Each conductor has a coloured insulation sheath. For protection against heat and damage the group of conductors is enveloped by a synthetic sheath, preferably of cross-linked polyurethane.
The cable may comprise several conductors that directly abut one another, particularly are stranded. The coating of the singular wires in each conductor can provide sufficient insulation between the conductors one to the other. The several conductors, for instance seven can be connected in series. In that way a plurality of windings is provided within the cable. By choosing the number of windings the desired sensitivity of the detection loop can be set. Furthermore, if not all conductors within the cable are used, in case of a conductor that is indeed used being damaged it can be replaced by a conductor that had been free up until then.
The cable may comprise a sheath with high-strength fibres, such as for instance Kevlar® to increase the tensile strength. Furthermore the cable can be provided with a layer of water-blocking material arranged around the conductor or group of conductors.
In a simple embodiment the cable is attached to the grid elements by means of cable binders. Such work can be carried out accurately and with ease. The cable binders may be tie-wraps, preferably having a metal locking strip in the locking end. The metal locking strip provides a high degree of reliability of the closure under the arising forces.
If the locking ends are situated vertically adjacent to the cable and the tie-wraps have been cut off outside of the locking ends, the height of the device can be kept limited, which is advantageous when the device comes to lie directly underneath the covering layer of the road surface.
The material for the carrier preferably is a material used as reinforcement of asphalt road surfaces, as for instance known from European patent 0 318 707 . As a result of its open structure and the suitable impregnation this grid material has the advantage of not being detrimental to the quality of the road surface, particularly as regards the adhesion between the top layer and the sub layer. This is particularly important as in this way the carrier is able to cover a large surface area. Reference can also be made to European patent application 0.199.827 , US patent 5.393.559 and US patent 8.038.364 the contents of which should be considered inserted herein. In one embodiment according to the invention the grid elements are made of continuous fibres, particularly glass fibres (such as glass silk), and have either been impregnated or coated, particularly with a material that is compatible and particularly connectable with the asphalt of the road surface layers, particularly an asphaltic resin or an asphaltic resin containing material. A suitable grid is Glassgrid® having a 1 x 1 cm mesh width, preferably 2.5 x 2.5 cm (type 8550).
The grid elements may form an open fabric with each other, wherein the grid elements comprise a group of first grid elements and a group of second grid elements that are perpendicular to the first grid elements, wherein in one embodiment, at the location of the intersections the second grid elements engage the first grid elements in an adhering manner at the upper side and lower side thereof for securing the intersection in the direction of the second grid elements. In that way the height of the carrier can remain limited, while preserving sufficient strength. In the second grid elements the continuous fibres can be slightly twined. In the first grid elements the continuous fibres can be parallel to each other. The flatness of the carrier can furthermore be kept limited if the first grid elements of the first group are flat-strip-shaped.
In one embodiment the device is rolled up, preferably with the loop on the concave side of the carrier. The first grid elements can extend parallel to the axis of the roll. This may be advantageous in case the carrier is rolled out in the work in the direction of the roadway. The connections at the location of the second grid elements extending over and under the first grid elements are able to resist the shearing forces caused by the material driving over the grid, so that the meshes of the grid can remain substantially intact.
The loop can be substantially rectangular with long sides and short sides, wherein the second grid elements extend in the direction of the long sides.
At the lower side, the grid elements can be provided with an adhesive that adheres to an asphalt surface and preferably is pressure-activated. In that way the grid can easily be stored and transported in rolled up condition, and easily be arranged.
Ease of placement is enhanced if the grid-shaped carrier can be bent out of its plane, particularly can be rolled up, in a second direction perpendicular to the first direction.
For connection of the loop to the loop coupling box, the cable will usually be provided with connecting sections. In that case it will be advantageous if the carrier has a main portion for carrying the loop and a part projecting therefrom, forming one unity with the main portion and to which a part of the connecting sections that connects to the loop is attached. The connecting sections are then kept in place in the road surface by the carrier that is already present for the loop. In that way installation becomes simpler and more reliable. The part of the connecting sections attached to the carrier may have a length of one or more dm, for instance to span the distance between the loop and the road side.
In case the loop is elongated the projecting part of the carrier can project in a direction transverse to the longitudinal direction of the loop.
In an alternative description, when the cable comprises connecting sections for connection of the loop to a loop coupling box, the loop can be attached to the carrier together with a part of the connecting sections that connect to the loop.
The connecting sections may extend with a portion to beyond the carrier and at that location preferably be rolled up.
On one and the same carrier several cables can be attached in loops situated adjacent to each other.
According to a further aspect the invention provides a method for disposing a detection loop device for vehicles according to the invention in a road surface, wherein the device in rolled up condition, with particularly the cable on the concave side of the rolled up carrier, is supplied to the work, rolled out on a basis surface, adhered thereto and subsequently an asphalt layer is applied. In one embodiment the device is adhered to the top surface of an asphalt-containing intermediate layer or sub layer. In one embodiment the asphalt layer is the top layer or covering layer of the paving in question so that the loop sits relatively high in the road surface which is advantageous to the signal strength and repairs to the loop.
In a simple embodiment the device is adhered to the basis surface by means of a pressure-sensitive adhesive applied thereon.
The roll can be rolled out in roadway direction of the traffic that will be using the road surface.
According to a further aspect the invention provides a road surface provided with a vehicle detection device according to the invention.
According to a further aspect the invention provides a traffic system, such as a system including traffic lights, comprising a road surface according to the invention.
The particular construction of the cable itself renders it resistant to the high temperatures and large dynamic forces that arise during applying the top layer, whereas the grid-shaped flexible carrier serves for easily placing the detection loop on the base and for its fixation during applying the top layer. As the cable has multiple cores it is easily possible to vary the number of windings of the loop, so that the sensitivity of the detection loop can be increased.
According to a further aspect the invention provides a cable, particularly to be used as detection loop in a road surface for vehicles, wherein the conductor has a number of singular wires each provided with a heat-resistant coating, particularly lacquer, and together forming a core or litze wire, wherein preferably the singular wires have been stranded into the conductor. In one embodiment only the singular wires are provided with the heat-resistant coating, particularly lacquer, wherein preferably the cable comprises several conductors that directly abut each other, particularly have been stranded. The cable may comprises a number, preferably seven electric conductors that can be connected in series. The coated singular wires may be wires used for electromagnetic coils, such as enamelled copper wire. The heat-resistant coating may also be ceramic.
According to a further aspect the invention provides a detection loop for a road surface, particularly an asphalt road surface, comprising a strip-shaped carrier with an electric conductor attached thereto, which have been put in the desired loop shape in advance and are suitable to be attached to a sub layer of the road surface, before the top layer of the road surface is disposed over it, wherein the conductor is attached to the carrier in advance in the desired configuration, which carrier is formed by a strip of open fabric impregnated with a resin, and the conductor consists of a multiple core cable, which on the outer circumference is provided with a sheath able to absorb high temperatures and high tensile forces, and each core is provided with its own ceramic insulation so that a loop of several windings can be formed.
The aspects and measures described in this description and the claims of the application and/or shown in the drawings of this application may where possible also be used individually. Said individual aspects may be the subject of divisional patent applications relating thereto. This particularly applies to the measures and aspects that are described per se in the sub claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated below on the basis of an exemplary embodiment shown in the attached drawings, in which:

Figure 1 shows a top view of a grid-shaped carrier for a device according to the invention;
Figures 1A and 1B show a detail IA of figure 1 and a cross-section IB of figure 1, respectively;
Figure 2 shows a top view of a device according to the invention with the carrier of figure 1;
Figure 2A shows a detail of the attachment of a cable to the carrier in the device of figure 2;
Figure 3 shows an end of the cable in the device of figure 2;
Figures 3A and 3B show details of the cable end of figure 3;
Figures 4A-D show a few steps in a method according to the invention in the installation of the device in a road surface;
Figures 5 and 5A show a top view of an arrangement of an assembly of a number of joined devices according to the invention and a single device therein, respectively;
Figure 6 shows a top view of another arrangement of a number of devices according to the invention; and
Figure 7 shows a top view of yet another arrangement of a number of devices according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

In figure 1 a grid-shaped carrier 1 is shown, composed of first grid elements 2 and second grid elements 3 that are perpendicular to each other and in between them define square meshes. In this example the grid elements 2 and 3 are made of glass fibre filaments and have been impregnated/coated with an asphalt layer/asphaltic resin which is suitable in view of installation in asphalt layers. The first grid elements 2 are flat, the second grid elements 3 extend over and underneath the first grid elements 3, see figure 1 B, in which for reasons of clarity this is shown schematically. On the carrier lower side of the grid elements 2, 3 a layer of pressure-sensitive glue has been applied. In this example the mesh width of the grid 1 is 2.5 cm. An example of such a grid is GlasGrid® 8550 by Adfors St Gobain.
In figure 2, on its upper side, the carrier 1 is provided with a detection loop 5, which is formed by a cable 6 attached to the carrier 1 by means of cable binders 8, which as can be seen in the schematic depiction of figure 2A, have been arranged around the cable 6 and a grid element 2 and/or 3, for instance every 10 cm. The cut-off end 8b projects as little as possible from its locking end 8a. The cable binders can be TY-RAP® TYB 24MX. The locking end 8a sits adjacent to the cable 6 so that the height of the carrier with cable remains limited and is not significantly increased by the cable binders.
The cable 6 comprises a composed sheath 11, for instance having a TPR outer layer, a Kevlar sleeving and an XLPE inner layer. Said sheath 11 is also resistant to high temperatures. Within the sheath 11 a helically wound strip 12 is situated of material that swells under the influence of water in order to block migration of water in cable direction. Within the sleeving 12 thus formed there are a number of conductors or cores 13, in this example seven, see figure 3A, each consisting of a number of -for instance 16-stranded singular wires 14 of copper, each surrounded by a heat-resistant coating 15, see figure 3B. The singular wires may have a 0.2 mm diameter. The cable may have a diameter of approximately 6 mm, the cores 13 may have a cross-sectional surface of for instance 0.5 to 0.9 mm², for instance 0.5 mm². The heat-resistant coating, having a thickness of for instance 10-12 micron, on the singular wires may be a lacquer that has been hardened on the singular wires in an oven. Such a lacquer is known per se from singular wires in transformer coils, such as for round lacquered copper coil wire, heat class 200°C. Also see the so-called enamelled (copper) wire. The singular wires and the cores/litze wires stranded therefrom remain sufficiently bendable despite the lacquer. It can be permitted here that at bending of the cable the cores/litze wires or the singular wires slide along each other without the insulation between the cores/litze wires getting noticeably damaged.
The cable 6 is attached to the carrier 1 in the plant, wherein terminals 7a,b are disposed on the entry/exit parts of the cable 6, the so-called loop supply cables or connecting sections 9', 9". The connecting sections 9',9" may have a length adjusted to the work in question, for connection to a loop coupling box, for instance several meters and subsequently have been rolled up in the plant. The device 10 thus obtained - with the loop on the concave side- can be rolled up in direction X, with the axis of the roll in direction Y, and then be stored, and also be transported to the work in that condition. The carrier 1 can also be rolled up in direction Y. The carrier 1 can be rolled up onto itself (particularly in case of larger lengths) or on a piece of tubing (particularly in case of smaller lengths).
On site of the work, see figure 4A, the roll 110 of device 10 is wound off in direction X, parallel to grid elements 3, on the top surface 21a of an asphalt (intermediate or sub) layer 21 of for instance that sits on a foundation 20. The asphalt layer 21 may be part of a newly to be laid road surface or be part of an existing road surface, in which case the top layer situated above it and possibly also a part of the asphalt layer situated underneath it will have been milled away. When the device 10 is situated at the correct location and in the correct orientation, the pressure-sensitive adhesive 4 is activated (schematically shown with a slight hatching) by means of a roller 120 moved in direction X, so that the carrier 1 is firmly adhered to surface 21 a. In this way the detection loop is fixedly located at once, in the desired configuration and cannot -inadvertently- be changed in shape by passing equipment.
A sticky adhesive layer is subsequently applied over the asphalt (concrete) layer 21 and over the device 1, after which by means of an asphalt paver 130 the asphalt top layer 22 of the road surface is laid, see figure 4C. The paver 130 then moves in direction X, parallel to the grid elements 3. The road surface 100 with drive surface 22a, figure 4D, is now ready and the connecting sections 9',9" can be connected to a connection box, not shown, by means of terminals 7a,b. The grid-shaped carrier 1 here ensures for the dimensional stability of the loop, and also provides local reinforcement of the asphalt.
The combination of smaller diameter of the cores and the heat-resistant coating, particularly lacquer, of the thinnest conductive parts, the singular wires, with the selected materials render the cable particularly suitable for use as detection loop, particularly directly underneath a top layer in the road surface. Due to the high position a (highly) reliable signal can be obtained. However, it is also possible to position the loop deeper, as several cores, if deployed, form a coil, as a result of which the sensitivity of the detection loop is increased and a reliable signal is obtained despite the larger distance to a vehicle to be detected.
The multiple-core cable also has the advantage that if during asphalting possibly one or more cores of the cable have been damaged, another core can be used so that the desired number of active windings is nonetheless achieved.
Due to the optional larger sensitivity of the detection loop according to the invention it is also possible, during laying a new road surface, to place the detection loop deeper underneath the top layer spaced apart therefrom such as on the foundation layer or in case of a road surface having three asphalt (concrete) layers disposing it underneath the intermediate layer and on the sub layer. (Generally an asphalt road surface consists of three layers, namely a sub layer of approximately a 6 to 7 cm thickness, an intermediate layer of a 4 to 5 cm thickness and a top layer of a 3 to 4 cm thickness). In this way the advantage is achieved that in case of repairs to the road surface, or in case of replacing the top layer the detection loop can remain where it is and is not damaged. In case of replacing the top layer namely a few centimetres of the intermediate layer is milled away as well. During repairing the road surface it is of course also possible to dispose the detection loop according to the invention on the basis layer that has been milled free.
In figure 5 an arrangement is shown of four devices 110a-d that as regard build-up are comparable to the device 10, therefore having a cable 106a-d (corresponding with cable 6) which by means of tie-wraps is attached to a carrier 101a-d (corresponding with carrier 1, however, having different outer dimensions). The carriers 101a-d are now T-shaped, with a transversely projecting portion 119a-d for the connecting sections 109a-d, on which portion the connecting sections are secured by means of tie-wraps. Double loops 105a-d are attached to the carriers 101a-d. The connecting sections 109a-d are rolled up as regards their part that extends outside of the projecting portion 119a-d. In figure 5A this is shown more clearly for device 110a. The devices 110a-d are placed on an asphalt sub layer or intermediate layer transverse to the direction of driving X. This arrangement, with double loops that in the direction of driving are placed one behind the other can be used for speed measurements on motorways of in this case four lanes.
The devices 110a-d can be supplied in double rolled up condition, wherein, the main surface of the carrier 101a-d is rolled up in direction X and the projecting portion 119a-d in a direction transverse thereto. When being placed first device 110a is rolled out and adhered to the freely exposed asphalt surface. Then device 110b follows, wherein the projecting portion 119b connects to carrier 101a. After that device 110c follows, wherein the projecting portion 119c connects to carrier 101b. Finally device 110d follows, wherein the projecting portion 119d connects to carrier 101c. It can be seen that the projecting portions 119a-d differ in width with a differing distance between the connecting sections 109a, 109b, 109c and 109d, so that the connecting sections 109a-d can sit next to each other and the assembly thus obtained remains limited in height. The connecting sections 109a-d jointly exit, situated together, for connection to a loop coupling box, for instance placed in the verge of the road.
It is also possible that the carriers bear several loops, such as for instance the devices 210a,b shown in figure 6, and with their largest length are situated transverse to the direction of driving X. The carriers 201a,b are each situated in a lane, and each bear three loops 205a-c. The largest length of the devices 210 can here be adjusted to three lanes, for instance 9 m.
Figure 7 also shows a quadruple arrangement, having solitary devices 310a-b, which as regards build-up can be compared with the device 10, that means with a cable 306a-b (corresponding with cable 6) which by means of tie-wraps is attached to a carrier 301a-b (corresponding with carrier 1, yet having different outer dimensions). The projecting portions 319a-b of the carriers 301a-b are now relatively short. The longitudinal direction of the carriers 301a-b is parallel to the direction of driving X. The length in said direction may for instance be 20 m. Said arrangement can for instance be used in a crossroads with traffic lights, with four lanes, such as a lane for turning right, one for turning left and two for continuing ahead.
In figures 5-7, for the sake of clarity, the grid size is many times larger than it will actually be (for instance 2.5 cm).
The above description is included to illustrate the operation of preferred embodiments of the invention and not to limit the scope of the invention. Starting from the above explanation many variations that fall within the spirit and scope of the present invention will be evident to an expert.

Claims

Vehicle detection device to be accommodated in a road surface, comprising a cable having at least one electric conductor and a carrier, wherein the carrier is grid-shaped having elongated grid elements that in between them define grid meshes, wherein the cable is attached in advance in the desired loop shape on the grid elements of the carrier, wherein the carrier preferably can be rolled up at least in one direction.
Device according to claim 1, wherein the conductor has a number of singular wires each provided with a heat resistant coating, particularly lacquer, and together form a core or litze wire, wherein preferably the singular wires have been stranded into the conductor.
Device according to claim 2, wherein only the singular wires are provided with a heat resistant coating, particularly lacquer, wherein preferably the cable comprises several conductors that directly abut one another, particularly have been stranded.
Device according to any one of the preceding claims, wherein the cable comprises a number of electric conductors, preferably seven, that can be connected in series.
Device according to any one of the preceding claims, wherein the cable has a sheath with high-strength fibres, such as for instance Kevlar® and/or wherein the cable is provided with a layer of water-blocking material arranged around the conductor or group of conductors.
Device according to any one of the preceding claims, wherein the cable is attached to the grid elements by means of cable binders, wherein preferably the cable binders are tie-wraps, preferably having a metal locking strip in the locking end, wherein preferably the locking ends are situated vertically adjacent to the cable and the tie-wraps have been cut off outside of the locking ends.
Device according to any one of the preceding claims, wherein the grid elements are made of glass fibre and have been impregnated/coated with an asphaltic resin.
Device according to any one of the preceding claims, wherein the grid elements form an open fabric, wherein preferably the grid elements comprise a group of first grid elements and a group of second grid elements that are perpendicular to the first grid elements, wherein in one embodiment, at the location of the intersections the second grid elements engage the first grid elements in an adhering manner at the upper side and lower side thereof for securing the intersection in the direction of the second grid elements, wherein preferably the first grid elements are flat-strip-shaped, wherein preferably the loop is substantially rectangular with long sides and short sides, wherein the second grid elements extend in the direction of the long sides.
Device according to any one of the preceding claims, wherein the device is rolled up, preferably with the loop on the concave side of the carrier, wherein in case of dependency on claim 8, the first grid elements preferably extend parallel to the axis of the roll.
Device according to any one of the preceding claims, wherein on the side facing away from the loop, the lower side, the first and second grid elements are provided with an adhesive that adheres to an asphalt surface, and preferably is pressure-activated.
Device according to any one of the preceding claims, wherein the grid-shaped carrier can be bent out of its plane, particularly can be rolled up in a second direction perpendicular to the first direction.
Device according to any one of the preceding claims, wherein the mesh width exceeds 1x1 cm, preferably a few cm by a few cm.
Device according to any one of the preceding claims, wherein the cable comprises connecting sections for connection of the loop to a loop coupling box, wherein the carrier has a main portion for carrying the loop and a part projecting therefrom, forming one unity with the main portion and to which a part of the connecting sections that connects to the loop is attached, wherein preferably the part of the connecting sections attached to the carrier has a length of one or more dm, and/or wherein preferably the loop is elongated and the projecting part of the carrier projects in a direction transverse to the longitudinal direction of the loop, wherein preferably the connecting sections extend with a portion to beyond the carrier and at that location preferably are rolled up.
Device according to any one of the preceding claims, wherein the cable comprises connecting sections for connection of the loop to a loop coupling box, wherein the loop with a part of the connecting sections that connects thereto is attached to the carrier, wherein preferably the connecting sections extend with a portion to beyond the carrier and at that location preferably are rolled up.
Device according to any one of the preceding claims, wherein several cables are attached to the carrier in loops that are situated next to each other.
Method for disposing a detection loop device for vehicles according to any one of the claims 1-15 in a road surface, wherein the device in rolled up condition, with particularly the cable on the concave side of the rolled up carrier, is supplied to the work, rolled out on a basis surface, adhered thereto, preferably by means of a pressure-sensitive adhesive that has been applied to the carrier, and subsequently an asphalt layer, which preferably is the covering layer of the paving in question, is applied, wherein preferably the device is adhered to the top surface of an asphalt-containing intermediate layer or sub layer, wherein preferably the roll is rolled out in direction of driving of the traffic that will be using the road surface.
Road surface provided with a vehicle detection device according to any one of the claims 1-15.
Traffic system, such as a system including traffic lights, comprising a road surface according to claim 17.