GB2488854A

GB2488854A - Road or railway signalling using coloured ground-level lights

Info

Publication number: GB2488854A
Application number: GB1118323.3A
Authority: GB
Inventors: Alfred Sharing
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-03-09
Filing date: 2011-10-22
Publication date: 2012-09-12
Anticipated expiration: 2031-10-22
Also published as: GB201104009D0; GB201118323D0; GB2488854B

Abstract

An indication system for railways or roads in which a plurality of lights is set at ground level in the vehicle pathway. The lights may be automatically set by controlling points, signals 1 or traffic lights (112, Fig.11) or manually controlled. In railways, the system lights are set between the running rails indicate the route selected and whether or not it is safe to proceed (e.g. by showing different colours, such as red, green shown as open and filled circles in the figures - and/or white). In roads, the lights are embedded in the road surface and may indicate the correct route to take through a complex junction. They may only be visible from one direction so as to be seen by oncoming traffic only. The system may be implemented in a game or simulator.

Description

DESCRIPTION

TITLE

An Indication System for Railways and Roads.

This invention is a system for indicating to the driver of a railway vehicle or a road vehicle the correct route to take through a junction or interchange and whether or not it is safe to proceed. The system is completely automatic and requires no input from any human source other than for routine maintenance. No on-vehicle equipment is required. Notwithstanding this, manual control of the system is optional. This invention will make a significant contribution to road and railway safety at complex interchanges.

BACKGOUND

In the embodiment for railways, many accidents have occurred when trains have over-run a danger signal or when a train has been directed onto the wrong line. For example, at Ladbroke Grove, Paddington in 1991, thirty-one people were killed and more than five hundred and twenty were injured when a train passed through a red signal and ran into the path of an oncoming express train. This accident may not have occurred if the proposed invention had been adopted. The proposed system will provide the drivers of trains with additional information which will enable them to do their job more effectively and thus reduce the stress and possible errors attached to negotiating complex trackwork. It will significantly reduce the possibility of trains running through red lights as a result of driver error. The system is in addition to and not a substitute for any existing train control system.

In the embodiment for roads, collisions involving traffic at traffic lights and roundabouts are a very common thing. The marked out lanes often get obscured by traffic wear which causes drivers of vehicles to be unsure of the correct lane to be in and to drift off the correct path thus causing traffic accidents. The proposed system will reduce the possibility of such accidents because it is not subject to the traffic wear from which the marked out lanes suffer. The system is in addition to and not a substitute for any existing traffic control system.

ESSENTIAL FEATURES OF THE INVENTION

At busy railway and road junctions and intersections, a plurality of lights is set in the vehicle pathway to indicate the correct route to be taken by the train or road vehicle.

The lights are automatically set by the controlling signals or traffic lights. No on-vehicle equipment is required. This will significantly reduce the risk of accidents and make a valuable contribution to rail and road safety. Notwithstanding this, manual control of the system is optional.

IN THE EMBODIMENT FOR RAILWAYS

The normal method of directing a railway train through a network of railway lines is by control signals and turnouts or points' which are controlled from a signal box or control centre. Current practice allows a single signal, sometimes in conjunction with a route indicator, to be used to allow a train to traverse over a series of points in order to access the required track. The proposed indication system will make it possible to indicate to a driver the precise route which has been selected through a junction or interchange by showing a plurality of lights (hereinafter referred to as the SYSTEM LIGHTS) set between the running rails showing green if it is safe to proceed and red if it is not, with an option to show yellow if that is required for operational purposes.

Other colours may be used if preferred. The system is completely automatic; the system lights are controlled directly from the points and signal settings and require no input from the signal control centre or the driver.

Note (1) on terminology: Railway tracks merge or divide by means of turnouts which are also called points and often referred so as a pair ofpoints or a set ofpoints. These terms are interchangeable and are freely used in this document A crossover is a special case where two pairs ofpoints are used to enable a train to transfer from one running track to a parallel track A double crossover is also a common feature of trackwork In this specification, the green system lights should show the whole route through the junction or interchange, but it is only necessary to show the red system lights up to the first set of points or as far as is necessary for the enhancement of safety. This is explained and described in detail later in this document.

The proposed system will be particularly suitable for installation at complex railway junctions, crossings, principal stations and large termini with multiple approach and departure lines.

Examples of the Application for Railways The system will be here described by way of two examples and with reference to the accompanying drawings (figures 1 and 2). in each of these drawings, each pair of running rails is shown as a single line for clarity. All signals are shown as (1) and [1 (green) or [(red). System lights set to green are shown with an open circle (0); system lights set to red are shown with a closed circle (p).

Figure 1 shows a hypothetical complex junction Figure 2 shows a hypothetical large terminus.

In figure 1, a hypothetical complex junction consists of four main-line tracks -Up Slow (US), Up Main (tiM), Down Slow (DS) and Down Main (DM) -together with a two-line branch-line (BL), an Intermediate line (C), and two Sidings (5). The position of some of the signals is shown (1).

The example shows the points and signals set to allow a train to pass from the Up Slow (US) line into the Branch (BL) and also from the Branch (BL) into the Down Slow (DS), (green system lights, 0). At the same time red system lights (0) are preventing trains from crossing the junction from the Down Main (DM) and Down Slow (DS), or from the Up Main (UM).

Although all the relevant system lights for this example are shown in figure 1, it is important to note that all system lights must be screened so that they can not be seen by the drivers of trains travelling in the reverse direction. Therefore the driver of the train entering the branch can not see the system lights applicable to the train leaving the branch, and vice versa.

In figure 2, a hypothetical large tenninus consists often platforms with four main-line approach and departure tracks (Up and Down Slow shown as 100, Up and Down Main shown as 200) and two Suburban tracks (shown as 20). Trains entering the station can be directed to any one of a number of platforms and trains departing may be routed onto the appropriate departure line. The platforms are shown as shaded areas and marked P1 to P10; the signals (1) controlling the exits from those platforms are shown as j (green) or NI (red).

The example shows the points and signals set to allow a train to depart from platform 3 (P3) to the Up Slow departure line (at 100) and also to allow a train to depart from platform 5 (P5) to the Up Main departure line (at 200). The remaining signals at the ends of the other platforms (controlling the departure of trains from those platforms) are set red. The green system lights (0) set on the tracks at 2-1 and 2-2 give clear indications to the drivers of the trains ready to depart from platforms 3 (P3) and platform 5 (P5) respectively that the routes out to the departure lines are clear and that it is safe to proceed. The red system lights (0)) set on the tracks from the other platforms indicate to any driver waiting to depart from those platforms that the way is not clear and that it is not safe to proceed. Note that the green system..lights show the whole of the routes through the complex selected for the trains from platforms 3 and 5, but that the red system lights applicable to other routes only show as far as the first

S

set of points.

Where tracks serve a dual purpose, such as in this example where trains can travel in either direction (arrival and departure), two sets of system lights are required, one set for trains arriving at the station and another set for trains departing. Thus it is essential that all system lights are screened so that they can only be seen from the front by the driver of the train to which they refer and not from the back. For clarity in this example, only the system lights relating to the departing trains are shown.

In the given example, figure 2, other train movements may, or may not be allowed.

For example, the signals and green system lights could be set to allow a suburban train to enter platforms 9 or 10 (P9, P10) from the suburban arrival line (20) without affecting the trains departing from platforms 3 or 5. However, permission could not be given to allow any train to cross the path of one of the departing trains. The system lights for arriving trains would not be visible from the platforms or by the drivers of any train about to depart from the platforms and they are not shown on this diagram.

It is important to note that green system lights can not be set to allow train paths to cross because the signals themselves can not be so set.

If the system lights for the lull route controlled by any signal are set to red when the signal is at red, it may present a confusing picture to any driver who is negotiating the complex. It is normally only necessary for drivers to see their own cleared route in the form of a plurality of green lights. Therefore it is only necessary for the red system lights to go as far as the first set of points or intersection alter the controlling signal to ensure that the driver of any train using that track is aware that it is not safe to proceed. This is demonstrated in figure 2 (large terminus). However, this is not so prescribed in this invention and the option to extend the line of red system lights may be exercised if operational needs demand it. The lines of red system lights described in the example in figure 1 (complex junction) at UM, DM and DS as far as the intersection of the branch line is an example of this.

Basic control principle A principal feature of this invention is that it is completely automatic. The colour and line of the system lights are set by the signals and points settings; the points determine which line of lights is activated, the signals determine the colour (normally red or green). This is demonstrated in figure 3 which is here described.

In figure 3A -the points (2) are set for the left hand track and the signal (1) is red so a plurality of red lights (0) is illuminated to indicate that the points are set for the left hand track but that the signal is red showing that it is not safe to proceed. The lights along the right hand track are off.

In figure 3B -the points (2) are set for the left hand track but the signal (1) is now green so a plurality of green lights (0) is illuminated showing that it is now safe to proceed The lights along the right band track are still off.

In figure 3C -the points (2) are set for the right hand track and the signal (1) is red so a plurality of red lights (0) is illuminated to indicate that the way has been set for the right hand track but that the signal is red showing that it is not safe to proceed. The lights along the left hand track are off.

In figure 3D -the points (2) are set for the right hand track but the signal (1) is now green so a plurality of green lights (0) is illuminated showing that it is now safe to proceed The lights along the left hand track are still off.

Important features The full control system for an application as shown in the examples at figures 1 and 2 must incorporate several important features which will be here described. The control system must allow for the control of the system lights over a series of points, some trailing, some facing. The route for a train will be set by the signalling control centre by setting the points and ensuring that the way is clear before setting the signal to green. The signal can not be set to green until all the relevant points, including trailing points, are correctly set.

The signal, in conjunction with each pair of points will set the applicable system lights as far as the next pair of points, which then set the system lights for the section up to the next pair of points, and so on until the indicated route is complete. It follows, therefore, that each pair of points must have an associated control circuit as well as the signal itself which will control the length of track as far as the first set of points. In the example given in figure 2, the red system lights arc illuminated only as far as the first set of points.

Delayed return-to-red.

A delayed return-to-red' feature must be included to prevent the plurality of green system lights from extinguishing or returning to red as soon as a signal has returned to red. The reason for this is that current practice has a green signal returning to red as soon as the front of a train has passed it. Without a delay feature, this would mean that a line of green system lights would extinguish or return to red as soon as a train starts to move past the green signal, which would confuse the driver. It is necessary, therefore, for the system lights to remain at green until the front of the train has cleared them.

Separate supplies for the control circuits The electrical signals which feed the control circuits for the system lights are taken initially from the supplies to the signals and points. However the circuits themselves should be fed from separate supplies so as not to overload the supplies to the signals and points.

Mechanical signals and points Where the signals and points are operated mechanically, a suitable source of power is required to enable this system to be operated.

Separate supplies for the system lights The electricity supplies for the system lights must be taken from a dedicated supply which is independent of the supplies to the signals, points and other parts of the control circuits.

These features are all covered by the proposed control system which is now here described.

Electrical Control Circuits.

The control circuits described herein are not prescribed but serve to demonstrate that automatic control of the system lights is both feasible and simple. In this description, relay-based2 electrical control circuits are described. However, it is recognised that other forms of control may be used, for example solid state devices.

Note (2) on relays: Relays are switching devices in which a coil operates a switch when it is energised. The switch is connected physically to other switches which may be part of other electrical circuits. These switches may be normally open or normally closed When the coil is de-energised, the switches revert to their original state. Relays are normally low-current devices with loads measured in milliamps and most signals and points electrical systems can bear the additional loads which this form of control system will put on them. In the figures attached to this section these are represented as A timer relay is one which operates when the coil is energised but when the coil becomes de-energised, there is a pre-set time delay before the relay returns to its normal state. In the figures attached to this section these are represented as a relay with the letter T attached, thus A special form of relay is the electrical contactor in which one of the switches is suitable for larger currents and thus can be used for switching loaded circuits on power supplies such as the system lights described in this document. In the figures attached to this section these are represented as a relay with the letter C attached, thus Relays, timer relays and contactors are industry-standard items.

A full control system incorporating all the features heretofore mentioned will consist of a number of modules which are illustrated in figures 4, 5, 6, 7 and 8 and described in the following paragraphs.

In these control circuits both the green and red pluralities of system lights are shown as controlled from the green signal only (except for figures 6) which gives an alternative option for facing points and figure 8 which gives an option for trailing points). This is to simplify the circuits as it is not necessary to have the green system lights set by the green signal and the red system lights set by the red signal independently. The signal can not show green and red at the same time so it is only necessary to use one of the signals to control both the system colours.

Figure 4 gives the control circuit for the first section of track after the signal as far as the first set of points. The system lights are governed by the signal only, as there are no points involved. The circuit shows the relay settings when the signal is green, (green system lights illuminated).

In figure 4, the line from the green signal light at G is connected to a timer relay 40 which has two integral switches at 40-1 and 40-2. The specification for this relay must state that the switch at 40-1 is normally open (n.o) in the de-energised condition while that at 40-2 is normally closed (n.c). The reason for this is that only the green or the red system lights can be illuminated at any one time, so when 40-1 is open, 40-2 is closed and vice versa. The switch at 40-i connects a DC supply to the electrical contactor at 41, which in turn connects the green line of system lights (1GSL) to the auxiliary power supply at A. This causes the green system lights to remain energised as long at the signal is green. When the controlling signal changes from green to red, the coil of the timer relay at 40 becomes de-energised but the contacts at 40-1 remain closed and 40-2 remain open for a pre-set time as determined by the timer setting before 40 returns to its normal de-energised position. This ensures that the lights do not immediately return to red as soon as the signal turns to red. When the timer relay at 40 returns to its normal de-energised state, the switch at 40-1 breaks open thus cutting off the power to the contactor and thus switching off the line of green system lights. At the same time, the switch at 40-2 now closes and power is supplied to the line of red system lights (RSL1) which remain illuminated until the signal turns green again. When the signal turns green, the red system lights go out and the green system lights come on with no delay.

A line is taken from the green signal light to the next set of points at PA. The electrical circuits are completed by connecting the lines to the relevant neutral returns at N. Each pair of points, whether facing or trailing has its own circuit controlling the system lights as far as the next set of points. These are shown in figures 5, 6,7 and 8 and are here described.

FigureS gives the control circuit for a set of facing points as shown in figure 3. In facing points there are two sets of system lights; one for the left hand track, a second for the right hand track. The points setting determines which set of system lights is activated. In this circuit, there is also provision for the control of red system lights although this part of the circuit (enclosed by the dotted lines in figure 5) can be 1-1 excluded if the red system lights are not required here. All system lights are controlled by the green signal. The system lights applicable to each track will extend as far as the next set of points or as far as is deemed necessary for operational purposes.

In figure 5 the contact at 5PL is energised when the points are set for the left band track and the contact at 5PR is energised when the points are set for the right hand track. SPL and 5PR can not be energised at the same time because the points can not be set for both lines at the same time. When the contact at SPL for the left hand track is energised, the relay at 50 becomes energised; when the contact at 5PR for the right hand track is energised, the relay at 55 becomes energised.. Again, 50 and 55 can not be energised at the same time. The relays 50, 51 (timer), 55 and 56 (timer) in this circuit must be specified such that the second pair of contacts in each relay (50-2, 51- 2, 55-2 and 56-2) are normally closed (n.c) when the relay is un-energised so that the switches open when they become energised.. Note that the contacts at 50-2 and 55-2 form part of the circuits controlling the red system lights for the other side of the points, so that when 50 is energised from the left hand points contact at 5PL, the switch at 50-2 in the circuit for the right hand side is open. Similarly when 55 is energised from the right hand points at 5PR, the relay switch at 55-2 in the circuit for the left hand side is open.. The purpose of this is to prevent both the lines of red system lights from being energised at the same time.

In detail, the circuit works thus: With the points in the left band position the relay at is energised and the contacts at 50-1 close and 50-2 open. When the signal is at green, the timer relay at 51 becomes energised which causes the electrical contactor 52 to apply power from the auxiliary supply at A to the line of green system lights for the left hand track, 5GL. Items 1) are power supplies whose function is to drive the relays at 52, 53, 57 and 58. With the contacts at 50-2 open and 5PR un-energised, power can not be applied to either the red or the green system lights for the right hand branch of the points. When the signal changes from green back to red, the signal contact at 0 becomes de-energised but the line of green system lights at 5CR remain illuminated until the pre-set time delay for the timer relay has expired when the relay returns to its normal un-energised state. At this point, 51-1 opens and 51-2 closes, thus switching off the green lights at 5GL and switching on the red lights at 5RL via contactor 53.

With the points set to the right hand position, the system works in exactly the same way for the right hand sets of system lights 50R and 5kR, using relays 55 and 56 with contactors 57 and 58. Separate supplies are provided at A to drive the contactors 52, 53, 57 and 58. A line is taken from each of the timer relay inputs to the next set of points in the cleared route at PB and PC. All circuits are completed by connections to the relevant neutral returns at N. Figure 6 gives an alternative circuit where the red signal controls the red system lights and the green signal controls the green system lights. The relays work in exactly the same way as depicted in figure 5.

The figure shows the state of the circuit when the points are in the left hand position and the signal is at green. 0 is the connection from the green signal, R is the connection from the red signal. 6PL and 6PR are the connections from the points actuators (left and right positions respectively). Lines to PB and PC connect to the next set of points. The contacts shown as S are energised, those shown as 0 are unenergised. D and A are auxiliary power supplies as described in the description for figure 5. As before, the switch contacts operated by the timers T are normally closed (nc) so that when the timer relay is energised, the switch opens. Only when the relay is in its rest position (unenergised) do those contacts close allowing the power to be fed to the red system lights. All circuits are completed by connecting to the neutral returns at N. Figures 7 and 8 show the system lights at a set of trailing points; figure 7 gives a schematic layout, figure 8 shows the control circuit.

hi figure 7, the arrow shows the direction of travel. Only green system lights are shown (S-S and T-S) though red system lights mat be included if required. The green system lights (T-S) can be controlled from one of two or more controlling signals (1,2 or 3). The system lights on the approach to the trailing points are set by the appropriate signal at 1,2 or 3. The position of the points does not matter as the lights are controlled only by the signals. The points must be set correctly for the train, otherwise the signal could not be set to green. Only one of the signals can show green (Q) at any one time; the other signal(s) will show red (S) The line of system lights shown as S-S and T-S in figure 7 will be set by the signal at 1. The control circuit is shown in figure 8 and described in the following paragraph.

In figure 8, the contact at 01 is energised when the signal at 1 in figure 7 is green while 02 is energised when the signal at 2 is green. The signals can not both be green at the same time, so both 01 and 02 can not be energised together. When 01 is energised, the relay at 80 is energised which brings in the supply for the timer relay at 81, which in turn energises the contactor at 82 which causes the line of green system lights (80) to illuminate. If the points are set for the other line and the other controlling signal is green, the appropriate contact at 02 or 03 will be energised and this will energise the appropriate relay at 83 or 85 which brings in a second supply to the timer relay 81. Again, this energises the contactor for the line of system lights as before. It is important to recognise that the circuits for the controlling signals can not be connected together so there can not be any feedback from one circuit to another. If there are other possible controlling signals such as signal 3 in figure 7, each of these will require a connection to the timer relay 81 through an appropriate relay (eg 85).

When the controlling signal returns to red, the system lights remain at green until the timer relay returns to normal after its pre-set time period.

If red system lights are required across these points, the circuit shown in figure 8 includes an optional additional pair of contacts on the timer relay at 81-2 which are normally closed and which bring in the red system lights (8R) through a contactor at 84. This optional part of the circuit is enclosed by a dotted line. The example in figure 1 where red system lights are shown on the Up Main (UM), Down Main (DM) and Down Slow (DS) are examples of when this may be considered necessary.

A line is taken from the input of the timer relay 81 to the next set of points at PD on the route which has been set for the train, to control the next set of system lights.

Note that 01, (12, 03 and X are the connections from the previous control circuits if the trailing points are not the first in line from the controlling signal. Additional power supplies A and D are as indicated in figure 6.

Sectioning of the system lights Figure 9 illustrates the sectioning over a typical route with the system lights at green.

The signal at (1) controls all the system lights as shown. The line of lights is divided into several sections: the first section (marked 9W) is up to the points at 9A; the second section (9X) between the points at 9A and the points at 9B; the third section (9Y) between the point at 9B and the points at 9C and so on until the system lights are no longer required. Each of these sections will have the delay-to-red feature as previously explained and each section can be set to a separate delay time. Typical delay times over a short stretch of the system might be 10 seconds for the first section, seconds for the second section and 30 seconds for the third section.

The equipment The equipment required is here described and illustrated in figure 10.

In figure bA, the system lights set between the running rails are shown thus Item 101 is the points actuator mechanism which operates the points at 102, item 103 is the signal, itemlO4 is the lineside system box which contains the power supplies and control circuits for the system lights. The lineside system box 104 is connected to the points mechanism 101 and the signal 103 as well as the system lights and any necessary power supplies.

In figure lOB, two views of a system light (105) with a hood and set between the running rails (106) are shown (front elevation and side elevations). It is not the intention of the author to give detailed embodiments of these items here but figure lOB shows a possible design which may be used.

The basic equipment list is as follows: * Lineside relay cabinets with auxiliary power supplies (item 104 in figure bA).

* Relays and timer relays as per industrial standard (within item 104 in figure bA).

* Contactors as per industrial standard (within item 104 in figure bOA).

* Cabling and connections to the points actuators or other points-operated switches * Cabling and connections to the colour-light signals or other signals-operated switches * System lights with cable connections and clips or fixing into the ground or onto the sleepers in the central space between the running rails.

All this equipment is industry standard or can be built up from industry standard equipment which is readily available. Some of the items may have to be custom-made using common materials and standard workshop practices. Such items may include: * System lights -two aspect or three aspect as required. All system lights will be inclined upwards at about ten degrees to make them visible to the driver.

* System light clips for fixing the lights to the sleepers or into the ground.

The essential design features which the lights must possess are: * The lights must be designed and fitted so that no part of the light or its housing is above the rail level when fixed in position, or above any point as directed in railway operating rules * The lights must be fixed in the centre line between the two running rails and facing the direction to which they refer so that they are clearly visible to the driver.

* The lights must be angled upwards about ten degrees.

* The lights must be contained within a waterproof housing * Two-aspect lights will show red or green; three-aspect lights will show red yellow or green. Three-core cabling will be required for the two-aspect lights (red, green and neutral return); four-core cabling will be required for the three-aspect lights (red, yellow, green and neutral return).

* Lights will be wired in parallel on the cable run.

* Lights will be fixed at intervals to suit the particular application.

* Where trains use a line in either direction, it will be necessary to have system lights pointing in opposite directions on the same length of track.

it is essential that all lights are screened so that they can only be viewed by trains travelling in the direction to which they apply.

Scope for further options In special circumstances, the system lights could be set to flash, rather than be just static, An alternative could be to have a running line of lights.

IN THE EMBODIMENT FOR ROADS

The invention proposes a plurality of green lights (hereinafter referred to as the SYSTEM LIGHTS) set into the road surface at busy junctions and intersections to indicate to the driver of a vehicle the correct route to take through the junction or intersection. The green system lights will be illuminated when the traffic light turns green and will be extinguished when the traffic light is amber or red. There is an option to install red system lights to indicate when the traffic light shows red.

The system is shown by examples in figures 11 and 12 and is here described.

Figure 11 describes a typical traffic-light controlled cross-roads for a road system in which the traffic drives on the left. The red and green system lights set into the road surface are driven from the appropriate traffic light: green system lights are driven from the green traffic light and red system lights from the red traffic light. The system lights may be driven directly from the traffic light or indirectly through a relay system connecting to an auxiliary power supply. The control system is not prescribed.

The example shows when the traffic lights at 111 are red and those at 112 are green..

Traffic entering the cross-roads from the top and both sides of the figure are therefore stopped. An option to set red system lights into the road surface at the stop lines is shown (s). The traffic lights at 112 are green, thus causing the green system lights (0) set into the road surface to illuminate and allowing traffic from the bottom of the figure to enter the cross-roads. The correct line for each stream of traffic is clearly indicated by the plurality of green system lights set into the road surface.

When the traffic lights change, the system lights automatically change to indicate the new traffic flows.

The representation of the lane arrows set in the roadway indicate the directions of traffic flow. The system lights can either be driven directly from the traffic light electrical supply or from an auxiliary supply which is switched by the traffic light.

Traffic lights at a busy junction like this allow each branch of the junction to go in turn.

Figure 12 describes a typical traffic-light controlled roundabout. The green system lights are set into the road surface to indicate the correct route to take when the traffic lights at 121 are green; those marked 122 are at red. The representation of the lane arrows set in the roadway indicate the directions of traffic flow. The system lights can either be driven directly from the traffic light electrical supply, or from an auxiliary supply which is switched by the traffic light. The example shows the system lights for traffic proceeding round the system from the bottom of the diagram when the traffic lights are green for them. Traffic lights at a busy roundabout like this usually follow a clockwise sequence to allow each branch of the junction to go in turn. When the lights change, other system lights not shown in this representation but presenting the same traffic flow pattern are brought into use.

The red system lights illustrated in this example are limited to showing when traffic must stop to await the onset of the green traffic lights. They will be controlled by the red traffic lights either directly or from an auxiliary supply switched in by the appropriate traffic light.

Scope for fur her ptions In special circumstances, the system lights could be set to flash, rather than be just static. An alternative could be to have a running line of lights

PRIOR ART

1. European patent application EP 2 135 037 (MITTERMAIB1t) discloses a route-finding system for locating a route within a terrain with a map databank of the terrain that contains node data and edge data, wherein nodes represent points on a path and edges represent the connections between nodes, and with a route search system that, with specified route parameters, determines an optimal route, wherein a route comprises at least several sub-routes, wherein each sub-route comprises at least one edge, wherein a difficulty detector is present, which difficulty detector takes the difficulty of the sub-routes into consideration in the route finding, wherein a user detector is present, which user detector detects the skills of the users, which determine the influence of the difficulty of the sub-routes on the found route in the route fmding, andlor a user selection, which determines the influence of the difficulty of the sub-routes on the found route in the route finding, wherein difficult sub-routes are characterised by the need to implement difficult manoeuvres to travel the sub-route; and wherein the difficulty detector in a route search system determines difficult manoeuvres on the basis of static route parameters and/or dynamic route parameters, wherein (a) the difficulty detector uses at least one of the following static route parameters for the determination of difficult manoeuvres: the presence of traffic lights at a turning point or a crossing point; the presence of a turning lane at a turning point or a crossing point; the need for a change of lane; whether the starting position of the manoeuvre is disposed in a road with right of way; and the gradient of the sub-route, andlor (b) the difficulty detector uses at least one of the following dynamic route parameters for the determination of difficult manoeuvres: the presence of a tailback on at least one lane of the road; the current lighting situation; the current time of day; and the current weather conditions.

2. European patent application EP 1 970 279 (IHIENSEN) discloses a camera unit which offers the possibility of surveying at a high speed and with sufficient quality comprising a housing, a camera positioned therein and lighting means for lighting the railway, characterized in that the camera is a matrix camera and in that the lighting means comprise light emitting diodes (LEDs).

3. International patent application WO 2008 107 141 (HAAG) relates to an illumination system for track systems with several parallel tracks, characterized in that light sources in the form of light bands are arranged on the exterior of the rail webs of the tracks.

4. German patent application DE 102005 038 083 (HOEGER) discloses a track for a railway tram (street car'), or urban light railway which crosses a road or a footpath at which point the track has rails whose upper surface incorporates an array of warning lights along the danger zone. The warning lights are automatically activated by the approach of a train. The lamps are incorporated within longitudinal grooves in the rail surface.

5. German patent application DE 20313 412 (ROETTCI{ER) discloses a lighting unit for illuminating railway tracks, platforms, and stations comprises an essentially elongate attachable element whose length can be varied to suit given conditions and/or requirements.

6. UK priority patent application GB 2 360 620 (HACKETT) discloses in all claims: a railway signal located between the railway tracks where the train wheels travel; wherein the signal light is located on the railway sleepers; wherein the signal light is located between the railway sleepers; wherein the signal light is powered by AC voltage; wherein the signal light is powered by DC voltage.

Note: IL4CKEIT (GB2 360 620, comprising part of GB 0006901) describes a single signal set between the tracks as a signal repeater to alert the train driver of the condition of the main signaL The current proposal is quite djfferent to this and should not infringe that pate nt.

7. UK patent application GB 2 255 431 (BARRASS) discloses a track based traffic regulation system which includes a series of light responsive elements spaced at intervals along at least part of the track and positioned to respond to light emitted from headlights of vehicles using the track or that part thereof and a series of light emitter elements also spaced along the track at locations visible to operators of vehicles approaching those locations along the track, each light responsive element being connected by transmitting or transducer means to one or more selected light emitter elements rearwardly thereof or otherwise remote therefrom so that the latter are activated sequentially in response to the headlights of a vehicle travelling ahead to provide a visible warning to a following vehicle or vehicle on and intersecting course of the presence and distance ahead of the first vehicle.

8. US Patent USD622676 (NICHIA CORP) discloses an ornamental LED display device.

9. International Patent W020l008056l (3M II'JNOVATWE PROPERTIES CO) discloses a flexible lighting assembly having a flexible cable, light emitting diodes and a heat sink.

10. US Patent USD619109 (LUNERA LIGHTiNG) discloses an LED module of ornamental design.

11. Japan Patent JP2O 10089704 (KYOSAN ELECTRIC MFG) discloses a method and system for controlling a signaller in an electronic cooperative system. This is concerned with a traffic light control method for the electronic gearing system of a railway. it is not thought to be in conflict with the current proposal.

12. US Patent US2009323358 (BRIDGELUX) discloses a track lighting system having heat sinks for solid state track lights. This is a track for a track lighting system comprising an elongated continuous track configured to support a plurality of solid state light fixtures 13. International Patent W02008 125162 (ROHDE & SCHWARTZ) discloses a route finding system and method having a route option to avoid hazardous turning manoeuvres.

14. US Patent US200S1 12170 (CREE) discloses a lighting assembly and components for lighting assemblies.

15. International Patent W02005059436 (1662801 ONTARIO) discloses a lighting assembly, beat sink and heat recovery system.

16. US Patent U52004223328 (AGILENT TECHNOLOGIES NC) discloses an illumination unit with a solid state light generating source, a flexible substrate and a flexible and optically transparent encapsulant.

17. China Patent CN2490418 (V/U BOBING) discloses a highway, railway tunnel lighting device.

18. International Patent W0200125681 (HUTCHiNS MARC)) discloses an elongated light emitting diode lighting system module.

19. France Patent FR2774403 (PRODUITS EN CIMENT) discloses an optic fibre illuminating system for incorporating in concrete structures.

20. GB Patent GB9612221 (CARROLL STEVEN V) discloses a visibility system for road traffic which comprises a plurality of units such that light shown on one unit causes light to be emitted from at least one further unit.

21. France Patent FR2745308 (VEZON PAUL) discloses an illumination line marking system for marking lanes on a road surface indicating pavement partition at night.

22. GB Patent GB9 109430 (BARRASS MARTIN I) discloses a traffic based traffic regulation system which includes a series of light responsive elements spaced at intervals along a road surface which respond to vehicle headlights.

None of these patents is thought to conflict with the present proposal and the proposal is not thought to infringe any of these patents Figure 1: The indication system at a hypothetical railway junction.

Figure 2: The indication system at a hypothetical railway terminus.

Figure 3: The basic control principle in the application for a railway.

Figure 4: A control circuit for the first section of system lights.

Figure 5: A control circuit for the system lights at a set of facing railway points (1).

Figure 6: A control circuit for the system lights at a set of facing railway points (2).

Figure 7: The system lights at a set of trailing railway points.

Figure 8: A control circuit for the system lights at a set of trailing railway points.

Figure 9: Sectioning of the system lights on a railway.

Figure 10: The basic equipment for railway application.

Figure 11: The indication system at a busy crossroads.

Figure 12: The indication system at a busy roundabout.

Claims

CLAIMS1 An indication system wherein a piurality of ground level lights on a railway track indicates to the driver whether or not it is safe to proceed by showing different colours (including the colour white) in response to an activation linked to points and signals or from a control centre.
2 A system according to claim 1 wherein a delay function is incorporated in the control circuit to prevent the plurality of lights from returning to a normal state until a pre-set time has expired.
3 A system according to any preceding claim wherein the lights are only visible from one direction.
4 A system according to any preceding claim wherein the lights are embodied so that no part of the light or its housing or any other part which lies between the running rails is above the rail level.
A system according to any preceding claim wherein the lights are embodied so that no part of the light or its housing or any other part which lies between the running rails is above any level dictated by the railway operating rules.
6. A system according to any preceding claim wherein the lights may be clearly viewed from the perspective of an approaching train driver's cab.

7 A system according to any preceding claim operating from a colour-light signal 8 A system according to any previous claim operating from a mechanical signal.9 A system according to any previous claim operating from mechanical or electro-mechanical points.An indication system of lights fixed into a roadway surface as route markers and showing the state of the traffic lights.11 An indication system of lights according to claim 10 which are driven directly from a traffic light or indirectly under the control of a traffic light.12 A system according to any preceding claim for use with any children's game.13 A system according to any preceding claim for use with any driving or training simulator.14 A system according to any preceding claim for use with any video game.An indication system of lights according to any preceding claim which is operated by AC or DC.AMENDMNETS TO CLAIMS HAVE BEEN FLEO AS FOLLOWSI. An indication system wherein a plurality of ground level lights on a railway track indicates to the driver of a train whether or not it is safe to proceed by showing a line of coloured lights in response to an activation linked to points and signals or from a control centre..2. A system according to claim I wherein any of the coloured lights is white..3 A system according to claim 1 wherein a delay function or a number of delay functions are incorporated in a control circuit to prevent the plurality of lights from returning to a normal state until a pre-set time has expired.4 A system according to any preceding claim wherein the lights are only visible from one direction.A system according to any preceding claim wherein the lights are controlled by a colour-light signal 6 A system according to any preceding claim wherein the lights are controlled by a mechanical signal.S..... *: *. 7 A system according to any preceding claim wherein the lights are controlled by *:. mechanical or electro-mechanical points.8. A system according to any preceding claim wherein the lights are controlled by a * *. control centre.9 A system according to any preceding claim for use with a video game.A system according to any preceding claim for use with a training simulator.