Terminal for a road barrier

Abstract

A collapsible terminal 100 for a road barrier comprises first and second sheets of material interlocking at a plurality of points 118a-c and shaped to form at least one collapsible cell 102a-d. The at least one collapsible cell is arranged along a longitudinal axis 103 of the terminal and is at least partly defined by one or more of the plurality of interlocking points. The first and second sheets of material rotate with respect to one another about at least one of the interlocking points under impact from a vehicle such that the at least one collapsible cell deforms to absorb energy of the impact. The interlocking points may be arranged along the longitudinal axis of the terminal. The sheets of material may comprise at least one slot to define the interlocking points. A collapsible terminal assembly comprises a plurality of terminals connected end to end. A barrier assembly comprises at least one collapsible terminal, a rail and at least one post.

Description

Technical field The invention relates to a collapsible terminal for a road barrier. Background Road barriers may be provided along a centre (e.g. along the central reservation) and / or along the sides of a road in order to prevent vehicles from exiting the roadway, or else entering the opposing lane(s) of traffic, and to protect road users from hazards. Typically, such road barriers comprise corrugated lengths of metal, mounted between posts anchored to the ground. These road barriers are designed to minimise injury to occupants of a vehicle that may impact the road barrier, however problems can occur if a vehicle impacts the end of the road barrier. For example, if the road barrier ends abruptly and a vehicle impacts the end of the road barrier head-on, there is a risk that the end of the road barrier may penetrate the vehicle without providing a decelerating force, causing serious injury or fatality. There exists a need to provide a way of safely decelerating a vehicle that impacts the end of a road barrier. Summary According to the invention in a first aspect, there is provided a collapsible terminal for a road barrier, the collapsible terminal comprising first and second sheets of material interlocking at a plurality of interlocking points and shaped to form at least one collapsible cell, the at least one collapsible cell arranged along a longitudinal axis of the collapsible terminal and being at least partly defined by one or more of the plurality of interlocking points, and wherein the first and second sheets of material are configured to rotate with respect to one another about at least one of the plurality of interlocking points under impact from a vehicle such that the at least one collapsible cell deforms to absorb energy of the impact. Optionally, the first and second sheets of material cross each other at the plurality of interlocking points. Optionally, the first and second sheets of material are shaped such that the at least one collapsible cell is a polygonal collapsible cell. Optionally, an interlocking point defines a corner of the polygonal collapsible cell. Optionally, the polygonal collapsible cell comprises a hexagonal or octagonal collapsible cell. Optionally, a major axis of the polygonal collapsible cell is aligned with the longitudinal axis of the collapsible terminal. Optionally, the first and second sheets of material form a plurality of collapsible cells, and wherein at least one of the collapsible cells is formed between adjacent interlocking points. Optionally, the first and second sheets of material are shaped such that the plurality of collapsible cells are polygonal collapsible cells. Optionally, the plurality of polygonal collapsible cells are arranged in a corner-to-corner relation along the longitudinal axis of the collapsible terminal. Optionally, each polygonal collapsible cell has substantially the same dimensions and shape. Optionally, the plurality of interlocking points are arranged along the longitudinal axis of the collapsible terminal. Optionally, the first and second sheets of material define walls of the collapsible cell(s). Optionally, the collapsible cells are arranged in series along the longitudinal axis, and wherein walls of the collapsible cells in the series located on a first side of the longitudinal axis are formed alternately by the first sheet of material and the second sheet of material, and wherein walls of each of the collapsible cells located on a second side of the longitudinal axis are formed alternately by the first sheet of material and the second sheet of material. Optionally, the first and second sheets of material each comprise at least one slot, and wherein the at least one slot of the first sheet of material engages the at least one slot of the second sheet of material to define at least one interlocking point. Optionally, the collapsible terminal further comprises at least one bracing member located within the, or each, collapsible cell and configured to reinforce the collapsible cell(s). Optionally, the at least one bracing member comprises a cross brace comprising a first strut and a second strut diagonally intersecting at an intersection point, and wherein the first strut and the second strut are configured to rotate about the intersection point upon impact of the vehicle with the collapsible barrier. Optionally, the collapsible terminal further comprises at least one lateral support member configured to resist movement of the collapsible cell(s) away from the longitudinal axis of the collapsible terminal upon impact of a vehicle in a direction substantially parallel to the longitudinal axis. Optionally, the at least one lateral support member is fixed to an outer surface of the collapsible cell(s). Optionally, wherein the at least one lateral support member comprises a lateral support plate comprising a first end fixed to a first collapsible cell and a second end fixed to an adjacent collapsible cell. Optionally, the collapsible terminal further comprises a plurality of pairs of lateral support plates arranged on opposed sides of the collapsible barrier. According to the invention in a further aspect, there is provided a collapsible terminal assembly comprising a plurality of collapsible terminals according to the first aspect, arranged in an end on end relation. According to the invention in a further aspect there is provided a barrier assembly comprising: at least one collapsible terminal according to the first aspect; a rail configured to be anchored to a ground upon which the collapsible terminal is to be mounted; and at least one post configured to couple the at least one collapsible terminal to the rail, the post configured to slide along the rail upon impact from a vehicle with the at least one collapsible terminal in a direction substantially parallel to the longitudinal axis of the at least one collapsible terminal. Optionally, the at least one post comprises a pin received within a guide track of the rail, and wherein the pin is configured to travel within the guide track of the rail such that the post slides along the rail upon impact from the vehicle. Optionally, the rail comprises a series of guide track sections each separated by a lug of material, and wherein the pin is configured to shear the lugs of material such that the pin is received within and travels within an adjacent guide track section as the at least one collapsible cell deforms upon impact from a vehicle. Brief description of the drawings Figure 1 shows a perspective view of an exemplary collapsible terminal; Figure 2 shows an exploded perspective view of an exemplary collapsible terminal; Figure 3 shows a top view of an exemplary collapsible terminal; Figure 4 shows a perspective view of an exemplary collapsible terminal assembly; Figure 5 shows a perspective view of an end of an exemplary collapsible terminal; Figure 6 shows a top view of an exemplary collapsible terminal; Figure 7 shows a perspective view of an exemplary lateral support member; Figure 8 shows a perspective view of an exemplary barrier assembly; Figure 9 shows a top view of an exemplary barrier assembly; Figure 10 shows a perspective view of an exemplary rail; Figure 11 shows a perspective view of an exemplary terminal assembly; Figure 12a shows a top view of an exemplary collapsible terminal; Figure 12b shows a top view of the exemplary collapsible terminal of Figure 11a in a first deformed state; Figure 12c shows a top view of the exemplary collapsible terminal of Figure 11a in a second deformed state; and Figure 13 shows a top schematic view of an exemplary collapsible terminal in a deformed state. Detailed description Generally disclosed herein is a collapsible terminal for a road barrier. The term “terminal” is used throughout this specification to refer to a structure configured to be attached to an end of a road barrier (and in some arrangements respective terminals may be attached at each end of a road barrier). The term “collapsible terminal” encompasses all structures that are attachable to the end of a road barrier and configured to deform under impact from a vehicle to facilitate controlled deceleration of the vehicle. As such, the term “collapsible terminal” encompasses crash cushions. The term “road barrier” is used herein to refer to a structure for preventing a vehicle from leaving a roadway. An exemplary road barrier may comprise one or more substantially horizontal elongate members supported by a plurality of substantially vertical posts such that the horizontal elongate members extend along the length of a roadway (e.g. along the side of a roadway). In some arrangements the horizontal elongate members may comprise lengths of W-section metal, although the skilled person will appreciate that substantially any length of material of any cross-section or shape may be used. Alternative exemplary road barriers may comprise one or more concrete blocks placed on the ground at the side of a roadway. The skilled person will appreciate that alternative arrangements may be used and the term road barrier encompasses any other suitable barrier for preventing a vehicle from leaving the roadway. The collapsible terminal disclosed herein comprises at least one collapsible cell, configured to deform upon impact of a vehicle with the collapsible terminal to absorb a force of impact of the vehicle. By absorbing the force of impact of the vehicle, the vehicle may be safely decelerated, and as such does not impact the end of the road barrier at full force. The collapsible terminal disclosed herein comprises first and second sheets of material that engage, or connect, at a plurality of points. The plurality of points are referred to as interlocking points because the first and second sheets of material interlock at the interlocking points. For the purpose of this description the term “interlock” is used to refer to a mechanical coupling or connection of the first and second sheets of material to resist movement of the first and second sheets of material with respect to one another. In particular, the term “interlock” is used herein to refer to a mechanical coupling or connection in which at least a part of the first and second sheets of material fit into one another, for example using corresponding slots. As such, the term “interlocking points” is used to refer to the points at which the first and second sheets of material interlock, e.g. the points at which the first and second sheets of material fit into one another. The first and second sheets of material are shaped to form the at least one collapsible cell when the first and second sheets of material are interlocked. The at least one collapsible cell may be at least partly defined by an interlocking point, and in particular, the interlocking point may define a corner of the at least one collapsible cell. In arrangements comprising a plurality of collapsible cells formed by the first and second sheets of material, the interlocking points may delineate adjacent collapsible cells, such that a first collapsible cell is formed on a first side of the interlocking point along the length of the collapsible terminal, and an adjacent collapsible cell is formed on the other side of the interlocking point. When a vehicle impacts the collapsible terminal, the first and second sheets of material rotate with respect to one another about the interlocking points such that the at least one collapsible cell deforms to absorb the energy of the impact. Figure 1 shows an exemplary collapsible terminal 100. The collapsible terminal 100 comprises a plurality of collapsible cells 102a-d. The plurality of collapsible cells 102a-d are arranged along a longitudinal axis 103 of the collapsible terminal 100. The term “longitudinal axis” is used herein to refer to a centre line along the length of the collapsible terminal 100, but the collapsible terminal 100 need not be symmetrical about the longitudinal axis. The collapsible terminal 100 shown in Figure 1 comprises four collapsible cells, however the skilled person will appreciate that this number is exemplary only, and that in alternative arrangements substantially any number of collapsible cells may be provided according to the terminal requirements. In the arrangement of Figure 1, all of the collapsible cells have the same dimensions. That is, all of the collapsible cells have the same shape, length, width and height The skilled person will appreciate that in alternative arrangements, the collapsible cells may have different dimensions and / or shapes to one another. As will be described in more detail below, a plurality of collapsible terminals 100 may be connected together in series to form a longer terminal assembly of a desired length. The collapsible terminal 100 further comprises lateral support members 104a-f and connecting portions 106a, 106b and 108a, 108b. As best shown in Figure 2, the collapsible terminal 100 comprises a first sheet of material 112a and a second sheet of material 112b. In exemplary arrangements, the first and second sheets of material 112a, 112b may comprise or be formed from structural steel or mild steel, however the skilled person will appreciate that any other suitable material may be used. The first and second sheets of material 112a, 112b are shaped to define the collapsible cells 102a-d when the first and second sheets of material 112a, 112b are connected to one another. In particular, the first and second sheets of material 112a, 112b are shaped to define walls of the collapsible cells 102a-d and a hollow section, or a cavity, within the walls of the collapsible cells 102a-d. The hollow section allows deformation of the collapsible cells 102a-d under impact, as will be described in more detail below. Each hollow section may extend along an axis perpendicular to the longitudinal axis 103. Each of the first and second sheets of material 112a, 112b comprise a continuous, length of material bent to form the walls of the collapsible cells 102a-d. The first and second sheets of material 112a, 112b may be bent such that they form a substantially continuous waveform, although as the skilled person will appreciate the waveform is not a smooth curve, but is rather formed of a plurality of straight, planar sections (or walls) that are angled with respect to one another to follow an approximate curve of a wave. The skilled person will appreciate that the first and second sheets of material 112a, 112b need not be formed by bending, and in alternative arrangements, may be formed by, for example, casting a metal or moulding a composite material, or any other suitable method. As can be seen in Figure 2, the shape of the first sheet of material 112a is a mirror image of the shape of the second sheet of material 112b. As such, when the first and second sheets of material 112a, 112b are engaged, for each individual collapsible cell, the walls located on a first side of the longitudinal axis 103 of the collapsible barrier 100, are formed by one of the first and second sheets of material 112a, 112b, and the walls located on a second side of the longitudinal axis 103 are formed by the other of the first and second sheets of material 112a, 112b. This can be clearly seen in Figure 3, which is a top view of the collapsible terminal 100 shown in Figure 1, with the lateral support members 104a-f omitted for clarity. As shown in Figure 3, the walls of the collapsible cell 102a on a first side of the longitudinal axis 103 (which in this instance is taken to be the side located “above” the longitudinal axis 103 shown in Figure 3) are formed by the first sheet of material 112a and the walls of the collapsible cell 102b on a second side of the longitudinal axis (which in this instance is taken to be the side located “below” the longitudinal axis 103 shown in Figure 3) are formed by the second sheet of material 112b. The walls of adjacent collapsible cells, located on a first side of the longitudinal axis 103, are formed alternately by the first and second sheets of material 112a and 112b. As shown in Figure 3 the walls of the first collapsible cell 102a on a first side of the longitudinal axis 103 (which in this instance is taken to be the side located “above” the longitudinal axis 103 shown in Figure 3) are formed by the first sheet of material 112a; the walls of the adjacent second collapsible cell 102b on the first side of the longitudinal axis 103 are formed by the second sheet of material 112b; the walls of the adjacent third collapsible cell 102c on the first side of the longitudinal axis 103 are formed by the first sheet of material 112a; and the walls of the fourth collapsible cell 102d on the first side of the longitudinal axis 103 are formed by the second sheet of material 112b. Similarly, the walls of adjacent collapsible cells located on a second side of the longitudinal axis 103 are formed alternately by the first and second sheets of material 112a, 112b. As shown in Figure 3 the walls of the first collapsible cell 102a on the second side of the longitudinal axis 103 are formed by the second sheet of material 112b; the walls of the adjacent second collapsible cell 102b on the second side of the longitudinal axis 103 are formed by the first sheet of material 112a; the walls of the adjacent third collapsible cell 102c on the second side of the longitudinal axis 103 are formed by the second sheet of material 112b; and the walls of the fourth collapsible cell 102d on the second side of the longitudinal axis 103 are formed by the first sheet of material 112a. As mentioned, the collapsible terminal 100 shown in Figures 1 and 2 comprises four collapsible cells 102a-d. As such, each of the first and second sheets of material 112a, 112b comprises four sections, 114a-d, 116a-d. The skilled person will appreciate however, that in alternative arrangements, the collapsible terminal 100 may comprise a different number of collapsible cells, and as such, the first and second sheets of material may comprise a corresponding different number of sections. Each section 114a-d, 116a-d defines walls of a single collapsible cell. More specifically, each section 114a-d of the first sheet of material 112a forms a first set of walls of a respective collapsible cell 102a-d, and each section 116a-d of the second sheet of material 112b forms a second set of opposed walls of a respective collapsible cell 102a-d along the longitudinal axis 103. The collapsible cells 102a-d shown in Figure 1 are octagonal, however the skilled person will appreciate that in alternative arrangements, the shape of the collapsible cells may be a different polygon. In the arrangement shown in Figures 1 and 2, each section 114a-d, 116a-d of the first and second sheets of material 112a, 112b defines four sidewalls. In alternative arrangements, the collapsible cells 102a-d may have a different shape, and as such each section of material 112a, 112b may define a different number of sidewalls, for example, one, two, three or more sidewalls. The first and second sheets of material 112a, 112b are shaped such that each collapsible cell is an irregular octagon, however in alternative arrangements, a regular octagon (or other polygon) may be formed. In further alternative arrangements, the collapsible cells 102a-d need not be polygonal, and may for example have curved sides. The first and second sheets of material 112a, 112b are configured to connect at a plurality of points. In particular, the first and second sheets of material 112a, 112b are configured to interlock at a plurality of interlocking points 118a-c. The interlocking points 118a-c are arranged along the longitudinal axis 103 of the collapsible terminal 100. As can be seen in Figure 1, the interlocking points 118a-c delineate one collapsible cell from an adjacent collapsible cell. In the arrangement shown in Figures 1 and 2, the first and second sheets of material 112a, 112b cross each other at the interlocking points 118a-c. As such, and as explained above, the walls of adjacent collapsible cells, located on the first side of the longitudinal axis 103, are formed alternately by the first and second sheets of material 112a and 112b, and the walls of adjacent collapsible cells, located on the second side of the longitudinal axis 103, are formed alternately by the first and second sheets of material 112a and 112b. The interlocking points 118a-c define a corner of each of the collapsible cells 102a-d. As such, the collapsible cells 102a-d are arranged along the longitudinal axis in a corner-to-corner relation to one another along the longitudinal axis 103, as opposed to a sidewall-to-sidewall relation. This can be best seen in Figure 3. As will be described in more detail below, the corner-to-corner relation provides a beneficial deformation / collapsing effect when the collapsible terminal 100 is impacted by a vehicle. As can be seen in Figure 3, a major axis of each of the collapsible cells 102a-d is aligned with the longitudinal axis 103. The interlocking points 118a-c are defined by slots 120a-f defined by the first and second sheets of material 112a, 112b. This is best shown in Figure 2. The slots 120a-c of the first sheet of material 112a correspond to the slots 120d-f of the second sheet of material 112b. When corresponding slots are slotted together, at least a portion of the second sheet of material 112b is received within each slot 120a-c of the first sheet of material 112a, and at least a portion of the first sheet of material 112a is received within each slot 120d-f of the second sheet of material 112b. In this way, the first and second sheets of material 112a, 112b interlock at the interlocking points 118a-c defined by the slots 120a-f. The slots 120a-c define each of the sections 114a-d of the first sheet of material 112a and the slots 120d-f define each of the sections 116a-d of the second sheet of material 112b. The slots 114a-f extend in a direction substantially perpendicular to the longitudinal axis of the sheets of material 112a, 112b, and extend from a top or bottom surface of the respective sheet of material along substantially half of the height of the respective sheet of material. In the arrangement shown in Figures 1 and 2, the slots 120a-c formed in the first sheet of material 112a extend upwards from the bottom surface of the first sheet of material 112a along substantially half of the height of the first sheet of material 112a, and the slots 120d-f formed in the second sheet of material 112b extend downwards from the top surface of the second sheet of material 112b along substantially half of the height of the second sheet of material 112b. As such, at least a portion of an upper surface of the first sheet of material 112a is received within each slot 120d-f of the second sheet of material 112b, and at least a portion of a lower surface of the second sheet of material 112b is received within each slot 120a-c of the first sheet of material 112a. In alternative arrangements, more than two sheets of material may be used to form the collapsible terminal. The skilled person will appreciate that in such arrangements, additional interlocking points, such as additional slots, may be used to interlock the sheets of material. The first and second sheets of material 112a, 112b, at each end thereof, define connecting portions 106a, 106b and 108a, 108b. The connecting portions 106a, 106b and 108a, 108b are configured to facilitate connection of the collapsible terminal 100 to other components, such as another collapsible terminal (to form a terminal assembly of a desired length) or a road barrier. The connecting portions 106a, 106b, 108a, 108b shown in Figures 1-3 facilitate connection of the first and second sheets of material 112a, 112b of the collapsible terminal 100, with first and second sheets of material of another collapsible terminal. As will be described in more detail below, the connecting portions 106a, 106b may also facilitate connection of the collapsible terminal 100 to an end nose. The end nose is connected to the end of the collapsible terminal 100 that is configured to face the oncoming traffic (i.e. the end of the collapsible terminal opposite to the end connected to the road barrier). The connecting portions 106a and 106b and 108a and 108b comprise a portion of the length of the first and second sheets of material 112a, 112b respectively. Each of the connecting portions 106a, 106b and 108a, 108b are configured to define part of a wall of a collapsible cell. As can be seen in Figure 3, the connecting portions 106a, 106b are each dimensioned to form the majority of a respective wall of collapsible cell 102d. The connecting portions 106a, 106b are of reduced length however, with respect to the corresponding walls of the other collapsible cells 102a-c formed by the first and second sheets of material 112a, 112b, and are configured to form a gap therebetween when the first and second sheets of material 112a, 112b are interlocked, as opposed to touching one another to form a corner of the collapsible cell 102d. The gap may advantageously facilitate assembly of the collapsible barrier 100, and specifically the interlocking of the two sheets of material 112a, 112b, by providing assembly tolerances. The connecting portions 108a, 108b are shaped to define a corner of a collapsible cell, such that when the connecting portions 108a, 108b of a first collapsible terminal 100 are connected to the connecting portions 206a, 206b of a second collapsible terminal 200 (which is substantially the same as the first collapsible terminal 100), a complete collapsible cell 202d is formed, adjacent to the collapsible cell 102a. This is shown in Figure 4. In this way, a continuous arrangement of collapsible cells in a corner-to-corner relation may be formed when connecting multiple collapsible terminals together. The lengths of material defined by the connecting portions may be connected by any suitable means, such as screws, rivets, or brackets. In the arrangement shown in Figure 4, the connecting portions 108a, 108b and 206a, 206b are connected together by a bracket 122. The collapsible terminal 100 shown in Figure 1 comprises an end nose 126. The end nose 126 is configured to provide a substantially planar impact area 128, to reduce the risk of the end of the collapsible terminal 100 penetrating a vehicle in the event of an end-on vehicle impact. The end nose 126 is formed of a substantially U-shaped sheet of material, with at least a portion of the connecting portions 106a, 106b being received within the U. The skilled person will appreciate that alternative end noses / components may be used to provide a substantially planar impact area. The collapsible terminal 100 may comprise a connecting bracket 129 configured to facilitate connection of the collapsible terminal 100 to a road barrier, as shown in Figure 5. In arrangements in which multiple collapsible terminals are connected together in series to form a terminal assembly, the collapsible terminal located at the end of the assembly for connection to the road barrier comprises the connecting bracket 129, and the opposite end of that collapsible terminal comprises a connecting member 106a, 106b or 108a, 108b to facilitate connection to another collapsible terminal, as described above. In arrangements in which only a single collapsible terminal is connected to a road barrier, that single collapsible terminal comprises a connecting bracket 129 at one end to facilitate connection to a road barrier, and connection members 106a, 106b at the other end to which an end nose, e.g. end nose 126, may be fixed. The connecting bracket 129 may comprise a connecting portion 131. The connecting portion 131 may comprise a length of material that substantially matches the shape and dimensions of the road barrier to which the collapsible terminal 100 is to be connected to. As such, the shape of the connecting portion 131 shown in Figure 5 is exemplary only, and the skilled person will appreciate that the shape and dimensions of the connecting portion 131 may change in dependence on the shape and dimensions of the road barrier to which the collapsible terminal 100 is to be attached. The connecting portion 131 may be configured to be secured to the road barrier. The connecting bracket 129 may be connected to connecting members 117a, 117b defined by the first and second sheets of material 112a, 112b. The connecting members 117a, 117b comprise a portion of the length of the first and second sheets of material 112a, 112b respectively. As can be seen in Figure 5, a first portion 121a, 121b of each of the connecting members 117a, 117b is dimensioned to form the majority of a wall of collapsible cell. The first portions 121a, 121b of each of the connecting members 117a, 117b are of reduced length, with respect to the corresponding walls of the other collapsible cells 102a-c formed by the first and second sheets of material 112a, 112b, and are configured to form a gap therebetween when the first and second sheets of material 112a, 112b are connected together rather than meeting to form a corner. Second portions 123a, 123b of the connecting members 117a, 117b are parallel to the longitudinal axis 103 of the collapsible barrier 100. The connecting bracket 129 may comprise a connection plate configured to be connected to the first portions 121a, 121b of each of the connection portions 117a, 117b, using for example, a bracket, bolts or other connecting means. The connecting portion 131 may extend from the connecting plate. The connecting bracket 129 may also be secured to the second portions 123a, 123b of each of the connecting members 117a, 117b using a bracket, bolts or other connecting means. In the exemplary arrangement of Figure 5, the connecting portion 131 of the connecting bracket 129 is secured to the second portions 123a, 123b of each of the connecting members 117a, 117b. The connecting portion 131 may be secured to the road barrier to fix the collapsible terminal 100 thereto. As can be seen clearly in Figure 3, the collapsible cell 102b is formed between the interlocking points 118a and 118b, and the collapsible cell 102c is formed between the interlocking points 118b and 118c. The cells 102a and 102d formed at either end of the collapsible terminal 100 may be defined between an interlocking point and an end connection 130 and 132. The end connections 130, 132 may be distinct from the interlocking points 118a-c in that the sheets of material 112a, 112b do not cross each other at the end connections 130, 132. Instead, the first and second sheets of material 112a, 112b are joined together at the end connections 130, 132 by way of the connecting portions 106a, 106b and 108a, 108b, and optionally an end nose 126 in the case of the collapsible cell located at the end of the collapsible terminal 100 facing the traffic. The end connection 130 comprises an end connection point that forms a corner of the collapsible cell 102a, such that the collapsible cell 102a is defined between the end connection point 130 and the interlocking point 118a. The end connection point 130 is located along the longitudinal axis 103 of the collapsible terminal 100. The end connection 132 is provided by the end nose 126, such that the collapsible cell 102d is defined between the end nose 126 and the interlocking point 118c. The collapsible terminal 100 comprises bracing members configured to reinforce the respective collapsible cells 102a-c. The bracing members comprise cross braces, although the skilled person will appreciate that alternative bracing arrangements may be used. Each cross brace is located inside the collapsible cells 102a-c, within the hollow section of the collapsible cells 102a-c, and extends between opposed inner walls of the collapsible cells 102a-c. Each cross brace is formed of a first strut 136a-c and a second strut 138a-c (see Figure 3) which diagonally intersect one another at an intersection points 140a-c. In exemplary arrangements, the first and second struts 136a-c, 138a-c each comprise slots extending from upper and lower surfaces respectively, at a point generally half way along the length of the first and second struts 136, 138. The slots may extend from the upper and lower surfaces of the first and second struts respectively along substantially half of the height of the first and second struts 136, 138. The first and second struts 136, 138 may be slotted together to form the cross brace. In this way, the first and second struts 136, 138 interlock at the intersection points 140a-c defined by the slots. The first and second struts 136a-c, 138a-c are fixed at either end to inner surfaces of the first and second sheets of material 112a, 112b. The cross braces are configured to provide some resistance to the collapse of the respective collapsible cells 102a-c, without preventing the collapse of the respective collapsible cells 102a-c upon impact of a vehicle with the collapsible terminal 100. Advantageously, and as will be discussed in more detail below, as well as reinforcing each collapsible cell 102a-c, the cross braces also act as an energy absorbing component as they are configured to deform upon impact of the vehicle with the collapsible terminal. In particular, the first and second struts 136a-c, 138a-c are configured to rotate with respect to each other about the intersection points 140a-c as the collapsible cells 102a-c deform on impact of a vehicle. As can be seen in Figure 3, the collapsible cell 102d positioned at the end of the collapsible terminal 100 that faces the oncoming traffic, which may be referred to as the front of the collapsible terminal 100, (i.e. the end of the collapsible terminal 100 opposite to the end that is joined to the road barrier), does not comprise a bracing member. This is to prevent a sharp initial deceleration of the vehicle upon impact of the vehicle with the end of the collapsible terminal (i.e. there is no resistance to the deformation of the collapsible cell from a bracing member). In other arrangements, the collapsible cell 102d positioned at the end of the collapsible terminal 100 that faces the oncoming traffic may be provided with a bracing member. As mentioned above, the collapsible terminal 100 comprises lateral support members 104a-f. The lateral support members 104a-f are visible in Figure 1 and Figure 6, which is a top view of the collapsible terminal 100. The lateral support members 104a-f are configured to resist buckling of the collapsible cells 102a-d (and therefore the collapsible terminal 100) in a direction away from the longitudinal axis 103 on impact of a vehicle in a direction substantially parallel to the longitudinal axis 103. In other words, the lateral support members 104a-f strengthen the collapsible terminal 100 against a side impact. The lateral support members 104a-f each comprise a sheet of material bent to form a V-shape. Each of the lateral support members 104a-f is fixed, at both ends, to outer surfaces of the first and second sheets of material 112a, 112b. The lateral support members 104a-f extend between adjacent collapsible cells 102a-d, such that a first end of each lateral support member 104a-f is fixed to a portion of the first / second sheet of material 112a, 112b that defines walls of a first collapsible cell, and the other end of each lateral support member 104a-f is fixed to a portion of the first / second sheet of material 112a, 112b that defines walls of an adjacent collapsible cell. As can be seen in Figure 6, the lateral support members are arranged in pairs, each lateral support member of the pair being fixed to opposed sides of the collapsible terminal 100 along the longitudinal axis 103. Each pair of lateral support members, 104a and 104b, 104c and 104d, and 104e and 104f is connected to the first and second sheets of material 112a, 112b such that the point of the V aligns with the respective interlocking points 118a-c along an axis perpendicular to the longitudinal axis 103. As can be seen in Figure 6, opposed lateral support members together with at least a portion of the cross braces, form a shape that substantially corresponds to the shape of the collapsible cells 102a-d. For example, the lateral support members 104a, 104b, together with the portions 142a, 142b of the cross brace disposed within collapsible cell 102a and the portions 144a, 144b of the cross brace disposed within collapsible cell 102b, form an octagonal shape that substantially matches the octagonal shape of each collapsible cell 102a-d. As such, a series of interwoven polygonal shaped portions are formed by the first and second sheets of material 112a, 112b, the cross braces, and the lateral support members 104a-f. Figure 7 shows a lateral support member 104a in isolation. The skilled person will appreciate that the lateral support members 104b-f are similar to the lateral support member 104a but mounted in different positions along the collapsible barrier 100. The lateral support member 104a comprises projections 146a-d and fixing portions 148a, 148b. The projections 146a-d comprise lugs 150a-d. The projections 146a-d are configured to be received within corresponding apertures 152a-d of the first and second sheets of material 112a, 112b (visible in Figure 4) and the lugs 150a-d retain the projections 146a-d within the apertures 152a-d. The projections 146a-d serve to locate the lateral support member 104 in the correct position relative to the first and second sheets of material 112a, 112b and retain it in position while the lateral support member 104 is fixed to the first and second sheets of material 112a, 112b. When the lugs 146a-d are received within the apertures 152a-d, the fixing portions 148a, 148b abut an outer surface of the first and second sheets of material 112a, 112b. The fixing portions 148a, 148b can then be secured to the outer surface of the first and second sheets of material 112a, 112b using appropriate fixing means, such as bolts, rivets, etc. The collapsible terminal 100 may be secured to the ground by a rail 156. The rail 156 is secured to the ground by anchors 160, as shown in Figure 8. The collapsible terminal 100 may be connected to the rail 156 to form a barrier assembly. The rail 156 comprises two beams 164 and 166 arranged in parallel to each other with a channel 168 formed therebetween, as shown in Figure 9, which is a top view of the barrier assembly comprising the collapsible terminal 100 and the rail 156. The collapsible terminal 100 is coupled to the rail 156 by posts 170 and 172. As can be seen in Figure 9, each post 170 and 172 is secured to the first and second sheets of material 112a, 112b of the collapsible terminal 100. Specifically, the posts 170, 172 are located in the hollow sections of the collapsible cells 102a and 102c, and attached to the inner walls of the collapsible cells 102a and 102c. The posts 170 and 172 may be attached to the inner walls of the collapsible cells 102a and 102c using bolts, or any other suitable fixing means. Figure 10 shows the rail 156 and the posts 170, 172 in isolation from the collapsible terminal 100. As is shown in Figure 10, the posts 170 and 172 are connected to the rail via pins 176 and 178 respectively. The pins 176 and 178 extend through the respective posts 170 and 172 in a direction perpendicular to the longitudinal axis of the posts 170 and 172 (and perpendicular to the longitudinal axis 103 of the collapsible terminal 100). The pins 176 and 178 are received within guide tracks of the rail 156. In the arrangement shown in Figure 10, a series of discrete guide tracks 180a-f are formed in the beams 164 and 166 of the rail 156. Only the guide tracks 180a-f formed in the beam 164 are visible in Figure 10, but a similar arrangement of guide tracks is formed on the beam 166. The guide tracks 180a-f extend along the length of the beams 164 and 166 in a direction parallel to the longitudinal axis of each respective beam 164 and 166. A thin lug of material separates each guide track 180a-f from an adjacent guide track 180a-f. The lug is dimensioned to shear under sufficient force to allow the pins 176 and 178 to travel from one guide track 180a-f to an adjacent guide track 180a-f. This will be described in more detail below. In the exemplary arrangement shown in Figures 8-10, the collapsible terminal 100 is secured to the rail 156 via two posts 170 and 172 located in alternate collapsible cells 102a and 102c. The skilled person will appreciate that in alternative arrangements, a different number of posts may be used to secure the collapsible terminal 100 to the rail 156. For example, a single post, or a post for each collapsible cell may secure the collapsible terminal 100 to the rail 156. Furthermore, these posts may be arranged in different collapsible cells to those shown in Figures 8-10. Installation of the collapsible terminal 100 will now be described with reference to the Figures 1-10. The rail 156 may be located in an appropriate position relative to the road barrier to which the collapsible terminal 100 is to be connected, and then secured to the ground via the anchors 160. As will be appreciated from the below description, because the collapsible terminal 100 can be easily assembled by slotting the first and second sheets of material 112a, 112b together, and then fixing the remaining components of the collapsible terminal thereto, the collapsible terminal 100 is able to be quickly formed at the installation site. This allows the different parts of the collapsible terminal 100, such as the first sheet of material 112a, the second sheet of material 112b, the lateral support members 104a-f and the first and second struts 136, 138 of each of the bracing members, to be transported to the installation site disconnected from one another. Therefore, the collapsible terminal 100 can be transported in a compact manner in comparison to known terminal arrangements, which are required to be transported in a pre-assembled state. The skilled person will appreciate however, that the collapsible terminal 100, or one or more elements of the collapsible terminal 100, may alternatively be pre-formed and transported to the installation site in an assembled state. The first and second sheets of material 112a, 112b may be interlocked to form the arrangement shown in Figure 3. That is, the first sheet of material 112a may be lifted above the second sheet of material 112b (as shown in Figure 2), such that the slots 120a-c of the first sheet of material 112a align with the corresponding slots 120d-f of the second sheet of material 112b. The corresponding slots 120a-c and 120 d-f may be fitted into one another to interlock the first and second sheets of material 112a, 112b at the interlocking points 118a-c. This forms the collapsible cells 120a-d. The bracing members may then be fixed to the first and second sheets of material 112a, 112b. In the arrangements shown in Figures 1-10 the bracing members comprise cross braces, each cross brace comprising first and second struts 136a-c, 138a-c. The first and second struts 136a-c, 138a-c may be slotted together to form the cross braces. The cross braces may then be positioned within the corresponding collapsible cells (in the arrangement shown in Figures 1-10 a cross brace is positioned within the collapsible cells 102a-c), and fixed to the inner surfaces of the first and second sheets of material 112a, 112b, using for example, bolts, brackets, screws or any other fixing means. The lateral support members 104a-f are fixed to the outer surfaces of the first and second sheets of material 112a, 112b. The lateral support members 104a-f are placed in position by locating the projections 146a-d and the lugs 150a-d of each lateral support member 104a-f within the corresponding apertures 152a-d of the first and second sheets of material 112a, 112b. In this position, the fixing portions 148a, 148b of each lateral support member abut the outer surface of the first and second sheets of material 112a, 112b, and the fixing portions 148a, 148b of each lateral support member are secured to the first and second sheets of material 112a, 112b using appropriate fixing means, such as bolts, rivets, etc. The collapsible terminal 100 may then be lifted into place on the rail 156, such that the posts 170, 172 are received within the collapsible cells 102a-d within which they are to be fixed. In the arrangement shown in Figures 1-10, the collapsible terminal 100 is positioned such that the posts 170 and 172 are received within the collapsible cells 102a and 102c respectively. The posts 170, 172 are slid into position against the inner walls of the collapsible cells 102a, 102c to which they are to be fixed. The posts are able to slide relative to the first and second beams 164, 166 of the rail 156 by virtue of the pins 176, 178 travelling within a respective guide tracks of the first and second beams 164, 166. Once in position, the posts 170, 172 are fixed to the inner walls of the collapsible cells 102a and 102c to secure them thereto. In this position, in the absence of a threshold force, the posts 170, 172 are unable to move with respect to the rail 156, as they are held in position by virtue of their connection to the collapsible terminal 100. The collapsible terminal 100 is connected at either end to one of: another collapsible terminal, the road barrier , or an end nose 126, by virtue of the connecting portions 106a, 106b, 108a, 108b or connecting members 117a, 117b and connecting bracket 129. In arrangements in which multiple collapsible terminals are connected in series, a similar process to that outlined above is followed in order to form each collapsible terminal and connect each collapsible terminal to the rail 156 (which may comprise further posts for connection to each further collapsible terminal). The collapsible terminals may then be connected together using the connecting portions 106a, 106b and 108a, 108b of each collapsible terminal to form a terminal assembly. The end of the collapsible terminal that is for connection with the road barrier comprises the connecting members 117a, 117b and a connecting bracket 129, and is connected to the road barrier using the connecting bracket 129. The end of the collapsible terminal that is configured to face the oncoming traffic is connected to an end nose 126 to form the substantially planar impact area 128. Figure 11 shows a terminal assembly comprising a plurality of collapsible terminals 100a-d connected in series. In the arrangement shown in Figure 11, four collapsible terminals 100a-d are connected in series, but the skilled person will appreciate that substantially any number of collapsible terminals may be used to form the terminal assembly, and the length of the rail and the number of posts may be adapted accordingly. Each collapsible terminal 100a-100c comprises connection portions 106a, 106b and 108a, 108b at either end thereof. The collapsible terminal 100d is configured for connection with the road barrier, and therefore comprises connection members 117a, 117b and a connecting bracket 129 at a first end for connection with the road barrier, and a connection portion 106a, 106b for connection to the collapsible terminal 100c. When a vehicle impacts the collapsible terminal 100, or a terminal assembly comprising a plurality of collapsible terminals 100 arranged in series (as shown in Figure 11 for example), the collapsible cells 102a-d are configured to deform to absorb the energy of the impact and provide a controlled deceleration of the impacting vehicle. The deformation of the collapsible cells 102a-d on impact from a vehicle in a direction substantially parallel to the longitudinal axis 103 of the collapsible terminal 100 is described with reference to Figures 12a-c. Figure 12a shows a schematic top view of the collapsible barrier 100 in an undeformed state, prior to impact from a vehicle. Although not shown in Figure 12a, the collapsible barrier 100 is attached to the rail 156 via the posts 170 and 172, as described above. The pins 176 and 178 of each of the posts 170 and 172 are received within first respective guide tracks 180a and 180e of the first and second beams 164, 166 of the rail 156. In this position, the posts 170 and 172 are unable to move with respect to the rail via the pins 176 and 178 travelling within the first respective guide tracks, because the posts 170 and 172 are held in position by the connection to the collapsible barrier 100. A vehicle may impact an end of the collapsible barrier 100 in a direction D, which is substantially parallel to the longitudinal axis 103 of the collapsible barrier 100. Specifically, the vehicle may impact the end nose 126 fixed to the collapsible cell 102d of the collapsible barrier 100. As described above, the end nose 126 provides a substantially planar impact area 128 for the vehicle, and as such, the collapsible terminal 100 does not pierce the impacting vehicle. As the vehicle impacts the collapsible barrier 100, the collapsible cells 102a-d are configured to deform to absorb the energy of the impact and decelerate the vehicle in a controlled manner that prevents piercing of the vehicle by the collapsible barrier 100 and reduces the impact forces experienced by occupants within the vehicle. Figure 12b shows a schematic top view of the collapsible barrier 100 as the collapsible cells 102a-d have begun to deform under impact from a vehicle in the direction D. As can be seen in Figure 12b, deformation of the collapsible cells 102a-d causes rotation of the first and second sheets of material 112a, 112b about one or more rotation points. The rotation points comprise the intersection points 118a-c, which as described above comprise the points at which the first and second sheets of material 112a, 112b are interlocked together. The walls of each of the collapsible cells 102a-d that extend from an interlocking point 118a-c (and which generally form a cross or x-shape) rotate about the respective interlocking point 118a-c in a direction away from the longitudinal axis 103 of the collapsible barrier. This rotation occurs as a result of the first and second sheets of material 112a, 112b bending about the interlocking points 118a-c. As such, some of the energy of the impact is absorbed to bend / deform the collapsible cell, and therefore the vehicle is decelerated. As can be seen in Figure 12b, the rotation points also comprise each of the remaining corners of the collapsible cells 102a-d, about which the remaining walls of the collapsible cells 102a-d rotate (i.e. those walls that do not extend from an interlocking point 118a-c). The walls rotate as a result of the first and second sheets of material 112a, 112b bending about the corners of the collapsible cells 102a-d, directed by the bending about the interlocking points 118a-c. As can also be seen in Figure 12b, for the collapsible cells 102a-d that comprise cross braces, which in this particular example are collapsible cells 102a-c, the deformation of the collapsible cells 102a-c also causes rotation of the first and second struts 136a-c and 138a-c of the respective cross braces about the intersection points 140a-c. In this manner, the cross-braces act as additional deformable / collapsible members to aid in the controlled deceleration of the vehicle, as well as reinforcing the collapsible cells 102a-d. In exemplary arrangements, the rear ends of each of the first and second struts 136a-c and 138a-c (i.e. the ends nearest to the road barrier) may be welded to the first and second sheets of material 112a, 112b to increase the stiffness of the cross braces. The front ends of each of the first and second struts 136a-c and 138a-c may not be welded to the first and second sheets of material 112a, 112b, but rather attached as described above. In such arrangements, the first and second struts 136a-c and 138a-c may also bend about the point at which they are welded to the first and second sheets of material 112a, 112b, to provide a further decelerating effect, on impact from a vehicle. Deformation of the collapsible barrier 100 further comprises deformation of the lateral support members 104a-f. As shown in Figure 12b, the lateral support members are bent as a result of the impact of the vehicle. In the exemplary collapsible barrier 100, the lateral support members are substantially V-shaped, and the walls of the lateral support members rotate, or bend, towards one another about the tip of the V on impact from a vehicle in the direction D. As can be seen when comparing Figure 12a to Figure 12b, as the collapsible barrier 100 starts to deform under impact from a vehicle in the direction D, the length of the collapsible barrier 100 decreases and the width of the collapsible barrier 100 (in a direction perpendicular to the longitudinal axis 103 of the collapsible barrier 100) increases. This is because the collapsible barrier 100 is shaped to facilitate deformation of the walls of the collapsible cells 102 in a direction away from the longitudinal axis 103 of the collapsible barrier 100. In particular, the polygonal shape of the collapsible cells 102a-d and corner-to-corner arrangement of the collapsible cells 102a-d provided by the interlocking points 118a-c promotes defomation / collapsing of the collapsible cell in a way that increases the width of the each collapsed cell 102a-d as the length reduces. Advantageously, this provides a larger surface area against which the vehicle abuts during impact, which aids in maintaining the travel of the vehicle in a direction substantially parallel to the longitudinal axis 103 during the impact of the vehicle. As the collapsible barrier 100 starts to deform under impact from a vehicle in the direction D, the collapsible barrier 100 is pushed along the rail 156. Specifically, under impact in a direction substantially parallel to the longitudinal axis 103 of the collapsible barrier, as the collapsible cells 102a-d begin to collapse / deform, the posts 170, 172 are pushed along the rail 156 as the collapsible barrier 100 collapses. The posts 170, 172 slide within the channel 168 formed between the two beams 164, 166 of the rail 156. This causes the pins 176, 176 to travel within their respective first guide tracks. For example, the pin 176 associated with the post 170 travels within the guide track 180e of the first beam 164 shown in Figure 10, and a corresponding opposed guide track located on the second beam 166 of the rail 156, and the pin 178 associated with the post 172 travels within the guide track 180a of the first beam 164 shown in Figure 10 and a corresponding guide track located on the second beam 166. As described above, the guide tracks are separated from one another by thin lugs of material. Under the force of an impact, the posts 170, 172 slide within the channel 168 and the pins 176, 178 move within the respective first guide tracks 180a, 180e until the pins 176, 178 reach the end of the respective first guide tracks 180a, 180e. The force of impact from a vehicle is large enough that the pins 176, 178 shear through the thin lug of material separating the first guide tracks 180a, 180e from the adjacent guide tracks 180b and 180f, and the pins 176, 178 then enter the adjacent guide tracks 180b, 180f, and continue to travel therein. This process is repeated as the collapsible barrier 100 continues to collapse and the posts 170, 172 continue to slide within the channel 168 of the rail 156. As will be appreciated, the lugs of material provide a further energy absorbing mechanism, and therefore a further decelerating mechanism. The process outlined above continues until the vehicle has been decelerated to a stop. Typically, at least some of the collapsible cells will be completely deformed, shown schematically in Figure 12c, and the walls of the completely deformed collapsible cells may touch one another and completely close the hollow sections formed within the collapsible cells (this is not shown in Figure 12c for clarity, however the skilled person will appreciate that this may occur in practice). In arrangements in which multiple collapsible terminals 100 are connected in series, for example as shown in Figure 11, the length of the terminal assembly may be designed such that at least some of the collapsible cells located at the end of the assembly connected to the road barrier, remain substantially undeformed after impact. This ensures that the vehicle does not impact the rigid road barrier, and therefore reduces the risk of the road barrier piercing the vehicle. The collapsible barrier 100 advantageously provides a number of features that resist bending / movement of the collapsible barrier away from the longitudinal axis during impact from a vehicle. This ensures that the deceleration direction of the vehicle is controlled. The skilled person will appreciate that one or all of these features may be used. Firstly, some resistance to lateral movement of the collapsible barrier 100 under impact is provided by interlocking the first and second sheets of material 112a, 112b. Because the sheets of material are interlocked together, and in particular slotted together, any eccentricity will be pulled back towards the longitudinal axis 103. Furthermore, the lateral support members 104a-f add lateral stiffness to the collapsible barrier 100, to prevent the collapsible cells 102a-d deforming in such a way that the collapsible barrier 100 is moved laterally away from the rail 154 under impact. Finally, the posts 170, 172 being received within the channel 168 of the rail 156 resists lateral movement of the collapsible barrier 100 under impact. The collapsible barrier 100 is also configured to absorb the energy of an impact from a vehicle in a direction angled with respect to the longitudinal axis 103. Deformation of the collapsible barrier 100 due to a side impact of a vehicle with the collapsible barrier in a direction D is schematically shown in Figure 13. Figure 13 is intended to show the deformation schematically only, and the skilled person will appreciate that the collapsible cells and lateral support members shown in Figure 13 are different to those presented in Figures 1-12 (for example, they have a different number of walls). The skilled person will appreciate that a similar effect will occur as a result of a side impact with the collapsible barrier 100 however, and similar reference numerals are used to refer to features of the collapsible barrier shown in Figure 13. As can be seen from Figure 13, upon impact from a vehicle in the direction D, the collapsible cells 102a-c deform as a result of rotation of the first and second sheets of material 112a, 112b about the interlocking points 118a and 118b and the intersection points 140a and 140b. Specifically, the first and second sheets of material 112a, 112b and the first and second struts 136a, 136b and 138a, 138b of the cross braces bend about these points to absorb the energy of the impact in a similar way to presented above in respect of Figures 12a to 12c. Instead of the collapsible barrier collapsing in a direction along the longitudinal axis however, a side impact such as that shown in Figure 13 causes bending of the first and second sheets of material 112a, 112b and the cross braces in a way that compresses the portion of the collapsible barrier at the front of the impact, and places the portion of the collapsible barrier to the side of the vehicle into tension. Although not shown in Figure 13, depending on the force of impact, the collapsible barrier may be pushed away from the longitudinal axis 103 and misaligned with the rail 156. This may cause bending or breaking of the posts 170, 172 attaching the collapsible barrier 100 to the rail 156, which acts to further absorb some of the force of the impact. It will be appreciated by the person of skill in the art that various modifications may be made to the above described embodiments without departing from the scope of the invention. The word “exemplary” is used herein to mean “an example”. Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

Claims

1. A collapsible terminal for a road barrier, the collapsible terminal comprising: first and second sheets of material interlocking at a plurality of interlocking points and shaped to form at least one collapsible cell, the at least one collapsible cell arranged along a longitudinal axis of the collapsible terminal and being at least partly defined by one or more of the plurality of interlocking points, andwherein the first and second sheets of material are configured to rotate with respect to one another about at least one of the plurality of interlocking points under impact from a vehicle such that the at least one collapsible cell deforms to absorb energy of the impact.

2. A collapsible terminal according to claim 1, wherein the first and second sheets of material cross each other at the plurality of interlocking points.

3. A collapsible terminal according to claim 1 or claim 2, wherein the first and second sheets of material are shaped such that the at least one collapsible cell is a polygonal collapsible cell.

4. A collapsible terminal according to claim 3, wherein an interlocking point defines a corner of the polygonal collapsible cell.

5. A collapsible terminal according to claim 3 or 4, wherein the polygonal collapsible cell comprises a hexagonal or octagonal collapsible cell.

6. A collapsible terminal according to any of claims 3 to 5, wherein a major axis of the polygonal collapsible cell is aligned with the longitudinal axis of the collapsible terminal.

7. A collapsible terminal according to any preceding claim, wherein the first and second sheets of material form a plurality of collapsible cells, and wherein at least one of the collapsible cells is formed between adjacent interlocking points.

8. A collapsible terminal according to claim 7, wherein the first and second sheets of material are shaped such that the plurality of collapsible cells are polygonal collapsible cells.

9. A collapsible terminal according to claim 8, wherein the plurality of polygonal collapsible cells are arranged in a corner-to-corner relation along the longitudinal axis of the collapsible terminal.

10. A collapsible terminal according to claim 8 or 9, wherein each polygonal collapsible cell has substantially the same dimensions and shape.

11. A collapsible terminal according to any preceding claim, wherein the plurality of interlocking points are arranged along the longitudinal axis of the collapsible terminal.

12. A collapsible terminal according to any preceding claim, wherein the first and second sheets of material define walls of the collapsible cell(s).

13. A collapsible terminal according to claim 12, wherein the collapsible cells are arranged in series along the longitudinal axis, and wherein walls of the collapsible cells in the series located on a first side of the longitudinal axis are formed alternately by the first sheet of material and the second sheet of material, and wherein walls of each of the collapsible cells located on a second side of the longitudinal axis are formed alternately by the first sheet of material and the second sheet of material.

14. A collapsible terminal according to any preceding claim, wherein the first and second sheets of material each comprise at least one slot, and wherein the at least one slot of the first sheet of material engages the at least one slot of the second sheet of material to define at least one interlocking point.

15. A collapsible terminal according to any preceding claim, further comprising at least one bracing member located within the, or each, collapsible cell and configured to reinforce the collapsible cell(s).

16. A collapsible terminal according to claim 15, wherein the at least one bracing member comprises a cross brace comprising a first strut and a second strut diagonallyintersecting at an intersection point, and wherein the first strut and the second strut are configured to rotate about the intersection point upon impact of the vehicle with the collapsible barrier.

17. A collapsible terminal according to any preceding claim further comprising at least one lateral support member configured to resist movement of the collapsible cell(s) away from the longitudinal axis of the collapsible terminal upon impact of a vehicle in a direction substantially parallel to the longitudinal axis.

18. A collapsible terminal according to claim 17, wherein the at least one lateral support member is fixed to an outer surface of the collapsible cell(s).

19. A collapsible terminal according to claim 17 or 18, wherein the at least one lateral support member comprises a lateral support plate comprising a first end fixed to a first collapsible cell and a second end fixed to an adjacent collapsible cell.

20. A collapsible terminal according to claim 19, comprising a plurality of pairs of lateral support plates arranged on opposed sides of the collapsible barrier.

21. A collapsible terminal assembly comprising:a plurality of collapsible terminals according to any of claims 1 to 20, arranged in an end on end relation.

22. A barrier assembly comprising:at least one collapsible terminal according to any of claims 1 to 20;a rail configured to be anchored to a ground upon which the collapsible terminal is to be mounted; andat least one post configured to couple the at least one collapsible terminal to the rail, the post configured to slide along the rail upon impact from a vehicle with the at least one collapsible terminal in a direction substantially parallel to the longitudinal axis of the at least one collapsible terminal.

23. A barrier assembly according to claim 22, wherein the at least one post comprises a pin received within a guide track of the rail, and wherein the pin isconfigured to travel within the guide track of the rail such that the post slides along the rail upon impact from the vehicle.

24. A barrier assembly according to claim 23, wherein the rail comprises a series of 5 guide track sections each separated by a lug of material, and wherein the pin is configured to shear the lugs of material such that the pin is received within and travels within an adjacent guide track section as the at least one collapsible cell deforms upon impact from a vehicle.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS:-CLAIMS:

1. A collapsible terminal for a road barrier, the collapsible terminal comprising: first and second sheets of material interlocking at a plurality of interlocking5 points and shaped to form a plurality of collapsible cells, wherein at least one of the collapsible cells is arranged along a longitudinal axis of the collapsible terminal, wherein at least one of the collapsible cells is formed between and at least partly defined by adjacent interlocking points, andwherein the first and second sheets of material are configured to rotate with10 respect to one another about at least one of the plurality of interlocking points under impact from a vehicle such that at least one of the collapsible cells deforms to absorb energy of the impact.

2. A collapsible terminal according to claim 1, wherein the first and second sheets 15 of material cross each other at the plurality of interlocking points.CM3. A collapsible terminal according to claim 1 or claim 2, wherein the first and second sheets of material are shaped such that at least one of the collapsible cells is a polygonal collapsible cell.CM 204. A collapsible terminal according to claim 3, wherein an interlocking point defines a corner of the polygonal collapsible cell.

5. A collapsible terminal according to claim 3 or 4, wherein the polygonal 25 collapsible cell comprises a hexagonal or octagonal collapsible cell.

6. A collapsible terminal according to any of claims 3 to 5, wherein a major axis of the polygonal collapsible cell is aligned with the longitudinal axis of the collapsible terminal.

307. A collapsible terminal according to claim 1, wherein the first and second sheets of material are shaped such that the plurality of collapsible cells are polygonal collapsible cells.

8. A collapsible terminal according to claim 7, wherein the plurality of polygonal collapsible cells are arranged in a corner-to-corner relation along the longitudinal axis of the collapsible terminal.5 9. A collapsible terminal according to claim 7 or 8, wherein each polygonalcollapsible cell has substantially the same dimensions and shape.

10. A collapsible terminal according to any preceding claim, wherein the plurality of interlocking points are arranged along the longitudinal axis of the collapsible terminal.1011. A collapsible terminal according to any preceding claim, wherein the first and second sheets of material define walls of the collapsible cell(s).

12. A collapsible terminal according to claim 11, wherein the collapsible cells are 15 arranged in series along the longitudinal axis, and wherein walls of the collapsible cells in the series located on a first side of the longitudinal axis are formed alternately by the first sheet of material and the second sheet of material, and wherein walls of each of the collapsible cells located on a second side of the longitudinal axis are formed alternately by the first sheet of material and the second sheet of material.2013. A collapsible terminal according to any preceding claim, wherein the first and second sheets of material each comprise at least one slot, and wherein the at least one slot of the first sheet of material engages the at least one slot of the second sheet of material to define at least one interlocking point.2514. A collapsible terminal according to any preceding claim, further comprising at least one bracing member located within at least one of the collapsible cells and configured to reinforce the collapsible cell(s) within which it is located.30 15. A collapsible terminal according to claim 14, wherein the at least one bracingmember comprises a cross brace comprising a first strut and a second strut diagonally intersecting at an intersection point, and wherein the first strut and the second strut are configured to rotate about the intersection point upon impact of the vehicle with the collapsible barrier.3516. A collapsible terminal according to any preceding claim, further comprising at least one lateral support member configured to resist movement of at least one of the collapsible cells away from the longitudinal axis of the collapsible terminal upon impact of a vehicle in a direction substantially parallel to the longitudinal axis.

517. A collapsible terminal according to claim 16, wherein the at least one lateral support member is fixed to an outer surface of a collapsible cell.

18. A collapsible terminal according to claim 16 or 17, wherein the at least one 10 lateral support member comprises a lateral support plate comprising a first end fixed to a first collapsible cell and a second end fixed to an adjacent collapsible cell.

19. A collapsible terminal according to claim 18, comprising a plurality of pairs of lateral support plates arranged on opposed sides of the collapsible barrier.1520. A collapsible terminal assembly comprising:a plurality of collapsible terminals according to any of claims 1 to 19, arranged in an end on end relation.20 21. A barrier assembly comprising:at least one collapsible terminal according to any of claims 1 to 19;a rail configured to be anchored to a ground upon which the collapsible terminal is to be mounted; andat least one post configured to couple the at least one collapsible terminal to the25 rail, the post configured to slide along the rail upon impact from a vehicle with the at least one collapsible terminal in a direction substantially parallel to the longitudinal axis of the at least one collapsible terminal.

22. A barrier assembly according to claim 21, wherein the at least one post 30 comprises a pin received within a guide track of the rail, and wherein the pin is configured to travel within the guide track of the rail such that the post slides along the rail upon impact from the vehicle.

23. A barrier assembly according to claim 22, wherein the rail comprises a series of 35 guide track sections each separated by a lug of material, and wherein the pin isconfigured to shear the lugs of material such that the pin is received within and travels within an adjacent guide track section as the at least one collapsible cell deforms upon impact from a vehicle.24 10 24

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