GB2621617A - Improvements in and relating to haul route junctions - Google Patents

Abstract

A portable traffic management system includes a barrier (120,Fig.3) which opens and closes one phase in synchronisation with a first traffic signal set A,B on the same phase. A detection system detects vehicles in a first zone (Z1,Fig.5) in front of the first traffic signal (i.e. approaching vehicles) and in a second zone Z2 behind it (i.e. vehicles clearing a junction behind the traffic signal). A control system controls the traffic signal to display a red stop signal on the second traffic signal and a green proceed signal on the first and to open the barrier based on detecting vehicles in the first zone and to display the opposite signals and close the barrier based on not detecting vehicles in the first zone. The barrier may additionally or alternatively be closed when no vehicle is detected in the second zone, thus controlling an ‘all red’ period of the traffic signals. Also disclosed is a portable traffic signal comprising a head supported on a post on a base and a forward (250,Fig.4) and rearward radar vehicle sensor (260,Fig.4).

Description

Improvements in and Relating to Haul Route Junctions Field of the Invention The present invention relates to a haul route junction typically installed at sites of major infrastructure projects to allow site vehicles, such as heavy plant, to safely cross public highways and bridleways and particularly, although not exclusively, to a haul route to main road junction where the traffic flow along the main route and the temporary haul route are both controlled by portable traffic signals.

Background

Haul routes, similar to temporary roads and used for site traffic, are used during construction projects and often may intersect with busy public highways and bridleways. These intersections (i.e. crossings or junctions) are a particular area of safety concern as they are used by a wide range of vehicles. For instance, it is known to construct a temporary haul route at major infrastructure projects to allow site traffic to safely move onto and about the site. Often, it is necessary for the temporary haul route to cross public highways and bridleways, and the examples given herein are to haul routes crossing a main road, that might typically have free flowing traffic moving at high speeds (i.e. 50mph / 80 Kph or more). Many of the site vehicles such as plant/Haul trucks, bulldozers, and excavators are large and characterised by limited manoeuvrability, relatively slow acceleration and deceleration and poor sight of line on each side of the vehicle. Given the site traffic moving along the haul route can move at different speeds, and that heavy plant or the like, will move at a relatively low speed with poor visibility, it is known to construct the haul route junction with a portable traffic management system to improve the safety of the junction for all users (i.e. public motorists moving along the main road and the site traffic). The portable traffic management system used at a typical haul route junction uses portable traffic signals to stop the main road traffic before allowing the site traffic to cross the main road along the haul route.

Figure 1 shows a typical two-phase haul route junction. Here, the first phase is shown as a temporary haul route, with the second phase being a main road. The temporary haul route is constructed to cross the main road at a right angle. Though of course, it will be appreciated that the exact layout of the crossing is not limited. Each direction of the haul route (first phase) is controlled by a first set of traffic signal heads (i.e. first and second traffic signals heads, one on each side of the junction facing opposed directions). And each direction of the main road (second phase) is controlled by a second set of portable traffic signal heads (i.e. third and fourth traffic signal heads, one on each side of the junction facing opposed directions). Each set of portable traffic signal heads will have an appropriate number of heads, so that users are provided with adequate displays, typically provided by the traffic signal head including coloured lights. For instance, each set of traffic signal heads is shown in Figure 1 as comprising two traffic signal heads facing each direction. Figure 1 therefore has eight traffic signal heads that operate in a controlled phasing as is known. The traffic signal heads are provided as part of one or more portable traffic signals. Each portable traffic signal may be associated with a single traffic signal head (i.e. a portable traffic signal may include a post, with a single traffic signal head facing one direction). But as shown in Figure 1, each portable traffic signal may have a plurality of heads (shown in Figure 1 with each portable traffic signal being associated with two traffic signal heads. Here, the multiple traffic signal heads on each portable traffic signal may face the same direction (for instance to have high and low displays) but in Figure 1, they are shown as facing opposed directions. Thus, one head forms part of the first set of traffic signal heads, and the other head forms part of the second set of traffic signal heads. It is known to use portable traffic signals in the manner described.

For example, it is known for each portable traffic signal to comprise a traffic signal head generally in the form of a red, amber and green light. Thus, the portable traffic signal system shown in Figure 1 might be operating with the first and second sets of portable traffic signal heads, provided via a number of portable traffic signals (shown in Figure 1 as four) with the heads of the first set controlled to activate the red light and the heads of the second set controlled to activate the green light. In this configuration, travel along the second phase (the main road) is unhindered and any traffic moving along the first phase (haul route) would be required to obey the red light and consequently be prevented from travelling across the main road. Typically, when a vehicle approaches along the haul route, the portable traffic signal system will be configured to run through the orange and red cycle on the second set of traffic signal heads in order to stop the flow of traffic along the main road. It is known to provide the portable traffic signals with a vehicle detector to detect approaching traffic along the haul route towards the junction and to activate the request for a green signal on the first set of heads automatically. The system can be configured with an 'all red' period, where both sets of traffic heads are controlled to display a red light in order to provide a predetermined period for the main road traffic to clear the junction. The system is then configured to run the red-orange-green phase on the first set of heads (i.e. to allow traffic flow along the first phase of the haul route). On the second set of heads displaying the green light, the site traffic (which might be a column of site traffic composing a number of vehicles) moves across the main road clearing the vehicle detectors that detect traffic approaching the junction along the haul route. After a predetermined time following the haul route detector clearing, the first set of heads on the haul route transition from green to red (i.e. the lights of each signal head display green, orange, then red lights). Again, typically the system is configured with an all-red period that is set at a minimum time needed for the slowest moving site traffic to clear the junction, before the system is configured to run the red to green phase on the heads of the second set of heads to open the flow of traffic along the main road.

Haul route junctions that use the conventional traffic management system described above in relation to Figure 1 and to manage plant vehicles and motorists crossing at the haul route junction, are not always appropriate to ensure the safe crossing of plant vehicles. For instance, because plant drivers can overlook the red signals. Furthermore, the traffic management system described does not prevent unauthorised vehicles from unknowingly entering the haul routes from the main road thus endangering the site workers and motorists. Therefore, to avoid these common mishaps, flaggers are often employed to manage these junctions. However, the use of these flaggers at these junctions can present unique challenges to maintaining safe and efficient operations. Furthermore, there is a requirement to reduce and minimise the delay to the main road by the traffic being halted at red lights, whilst the traffic management system also needs to balance the delay caused to site traffic being held at red lights on the haul route.

The present invention has been devised in light of the above considerations. In particular, it is an aim to provide an automated barrier system that manages access of vehicles to private sites and particularly from public roads. The system being especially suitable for managing haul routes and public main road crossings, ensuring that plants in the haul route can safely clear the crossing.

Summary of the invention

According to the exemplary embodiments there is therefore provided at least a two-phase portable traffic management system wherein a barrier system is controlled to open and close one phase in synchronisation with a first set of traffic signal heads on the same phase and a second set of traffic signal heads on a second phase, wherein a detection system is configured to detect vehicles in a first zone and a second zone. The first zone is configured to be in a forward direction relative to a traffic signal head of the first set in order to detect vehicles approaching the traffic signal head, and the second zone is configured to be in a rearward direction relative to the same traffic signal head in order to detect vehicles clearing a junction behind the traffic signal head. Advantageously, the barrier system can close the first phase to both prevent accidental entry to the first phase from vehicles passing across the junction and along the second phase under a green, proceed signal. That is, to prevent highway traffic from incorrectly turning into the haul route. And to reduce the likelihood of vehicles travelling along the haul route from overlooking the red signal and crossing the junction when it is not safe to do so (i.e. to only cross when the traffic signal heads on the main road is displaying a stop signal). Furthermore, advantageously, the second zone can be used to control an 'all red' period of the traffic signal heads. Here, the portable traffic management system is controlled to stay in the 'all red' period until the detection system does not detect a vehicle in the second zone.

In the exemplary embodiments, the barrier system is configured to at least open and close the entrance to the junction along the first phase (haul route) from both first and second directions. In alternative embodiments, the barrier system is configured to at least open and close the exit to the junction along the first phase (haul route) from both first and second directions. In further alternative embodiments, the barrier system is configured to at least open and close the entrance and exit to the junction along the first phase (haul route) from one or both of the first and second directions.

In the exemplary embodiments, the barrier system comprises a first barrier and a second barrier. In some embodiments comprising a first barrier and a second barrier, each barrier opens and closes one lane of traffic (i.e. traffic flowing in one direction but not the other). For instance, here, each barrier comprises an arm, and the arm is sized approximately the width of a single lane of the haul route. That is, when the barrier is closed, the arm extends across at least a portion of one lane of traffic and up to substantially the full width of one lane of traffic. In these embodiments, the first barrier might be located to open and close an entrance to the junction from a first side of the first phase and the second barrier might be located to open and close an entrance to the junction from a second side of the first phase. It will be appreciated that first and second barriers arranged to open and close the entrance to the junction (i.e. in the UK, the left hand lane of the haul route) allow the traffic management system to reduce the risk of site drivers moving along the haul route from overlooking a stop signal (red light). It therefore follows that alternatively, the first barrier might be located to open and close the exit from the junction from the first direction and the second barrier might be located to open and close the exit from the junction from the second direction. It will be appreciated that first and second barriers arranged to open and close the exit to the junction (i.e. in the UK, the right hand lane of the haul route) allow the traffic management system to reduce the risk of drivers turning into the site from the main road. Of course, arranging the first and second barriers on both the entrance and exit of the same side of the first phase so that each barrier opens and closes one lane, would provide both benefits but to only one side of the haul route. Therefore, where the barriers are arranged to open and close a single lane of traffic, it is envisaged that the optimal barrier system will comprise first and second barriers on the entrance to the junction (i.e. one to each side) and third and fourth barriers on the exit from the junction (i.e. one to each side).

In the exemplary embodiments, the barrier system comprises a first barrier and a second barrier. In some embodiments comprising a first barrier and a second barrier, each barrier opens and closes two lanes of traffic (i.e. each barrier is operable to open and close both the entrance and exit to the junction from the one side of the junction). For instance, here, each barrier comprises an arm, and the arm is sized approximately the width of a dual lane of the haul route. That is, when the barrier is closed, the arm extends across one lane of traffic and also up to substantially the full width of a second, parallel lane of traffic. In these embodiments, one barrier simultaneously opens and closes both the entrance and exit to one side of the junction along the haul route.

In embodiments where the barrier comprises an arm, the arm suitably pivots relative to a body. The pivot may be vertical or horizontal. But it is envisaged a horizontal pivot would be optimal, where the arm swings upwards.

In the exemplary embodiments, the barrier suitably includes an actuator such as a motor or the like for moving an arm between the open and closed positions. Furthermore, suitably the actuator is controlled by a barrier control. Here, the barrier control may connect to other components of the traffic management system. For instance, the barrier control may be wired to the other components and in particular to a traffic signal controller. Preferably, the barrier interface is wirelessly connected to a traffic signal controller. Here, the barrier further includes an antenna for enabling the wireless communication. In either embodiment, the barrier control is suitably configured to receive commands from the connected component of the system (i.e. the connected traffic signal controller) to move the arm into an open or closed arrangement and also to send status information back to the connected component of the system regarding the status of the barrier (i.e. whether the arm is in an open or closed arrangement). In the exemplary embodiments, the barrier control of each barrier is connected to a traffic signal controller, and in particular to a barrier interface of the traffic signal controller. In some embodiments, multiple barrier controls may be connected to the same traffic signal controller.

In the exemplary embodiments each traffic signal head suitably includes at least a stop signal and a proceed signal. Suitably, the stop signal is a red light and the proceed signal is a green light. For instance, each head suitably comprises an array of lights as is known in the art and typically a red, orange and green light, which are usually vertically arranged. As is known the heads typically form part of a portable traffic signal. Thus, in the exemplary embodiments, the portable traffic management system comprises at least one portable traffic signal. Each portable traffic signal includes a head. The head is suitably mounted on a post of the traffic signal. The traffic signal is portable and typically includes a base that provides ballast. Suitably the base provides a housing for containing control equipment such as a traffic signal controller. For instance, the traffic signal controller sends activation signals to the head to control and coordinate the display of the lights. The traffic signal controller is suitably connected to other components of the system for instance by wired or preferably wireless communication. In the preferable wireless connection, the traffic signal includes a transceiver to enable the wireless communication.

In suitable embodiments, the traffic signal controller may comprise a traffic signal interface and a barrier interface. Here, the traffic signal interface suitably provides an interface to the signal head and provides an interface to a sensor of the sensor system monitoring the first zone. The traffic signal interface also suitably provides the interface to other components of the system (i.e. another traffic signal), for instance either by wired connection, or preferably by providing an interface to a transceiver for wireless communication. In this instance, the traffic signal interface may comprise an existing traffic signal interface. The barrier interface suitably provides the interface to an associated barrier (or barriers) and to a sensor of the sensor system monitoring the second zone. As explained, the interface to the barrier (i.e. barrier control) may be a wired connection or preferably a wireless connection wherein the barrier interface connects to the barrier control via a transmitter! receiver. Conveniently, the barrier interface can therefore be plugged into existing traffic signals to advantageously adapt the traffic signal to operate within the improved traffic management system herein provided. It will be appreciated that where the traffic signal controller of each traffic signal is described as comprising a barrier interface and a traffic signal interface, the interfaces may be separate hardware (partially if retrofitting the functionality to existing traffic signals) or may be provided as integrated hardware, or even may be distributed across different components of the system.

Consequently, in the exemplary embodiments, each traffic signal controller may send activation signals to control the barrier system as well as to communicate a status of the connected traffic signal head or to send timing signals to other traffic signals in the first traffic signal set or to the second traffic signal set.

That is, as will be described herein, the traffic management system is suitably configured with a plurality of traffic signals in a master and slave arrangement, wherein one traffic signal within the system comprises a master device that centralises the control algorithm for the system and sends command signals to any other traffic signals within the system. The other traffic signals in the system would therefore be slave traffic signals, wherein the respective traffic signal controller of a slave traffic signal would be configured to receive timing signals from the traffic signal controller of the master traffic signal and to control its head accordingly and to also send status information back to the master traffic signal controller regarding the status of the device (i.e. which light is displayed).

Each traffic signal within the system may be associated with a barrier or multiple barriers. Moreover, multiple traffic signals may be associated with the same barrier. The master traffic signal could be configured to send control signals to each barrier (i.e. to the barrier control of each barrier) in the system, but it is envisaged that in preferable embodiments, slave traffic signals may directly control associated barriers, with the master traffic signal only directly controlling its associated barrier. That is, a slave traffic signal controller may receive and send barrier control information (i.e. the activation signals from the master signal controller for the barrier to move to a different position, and to send the status information back) for an associated barrier to the master traffic signal controller. Here, the associated barrier would be connected to the slave traffic signal controller to send and receive the control information.

As explained, the first traffic management system includes a sensor system for detecting vehicles in first and second zones along the first phase (haul route). It is known to use a sensor system on a traffic signal to detect vehicles in a first zone. It is envisaged the first zone will be configured to operate to detect vehicles approaching the traffic signal as is known in the art. Here, information from the sensor system regarding vehicles entering the first zone is communicated to the traffic signal controller of the associated traffic signal. As explained, the sensor system may suitably communicate information from the first zone to the traffic signal interface. Where the traffic signal is configured as a slave traffic signal, the slave traffic signal controller sends the information to the master traffic signal controller for processing. Where the traffic signal is configured as the master traffic signal, the signal information is processed by the master signal controller. The first zone may therefore be considered as a 'call' signal, wherein detecting vehicles entering the first zone sends a 'call for green' request for the master traffic signal controller to activate a change in the traffic signal heads.

The second zone operates similarly to the first zone to detect vehicles as is known in the art, but as explained, the second zone is configured to cover an area behind the traffic signal head to detect when vehicles have exited from the second zone. By arranging the second zone to cover an intersection of the two phases, the second zone can detect when vehicles have exited the junction meaning it is safe to allow the system to change flows. This is important when combined with the use of barriers as if the barriers are allowed to close with site traffic waiting to clear the junction, the site vehicles can become trapped in the junction, which could block the main road. The sensor system therefore communicates with the traffic signal controller to process the signal information Of it is a master) or to send the signal information to the master traffic signal controller for processing (if it is a slave). The second zone may therefore be considered as an 'all red detector' wherein the master traffic signal controller does not begin to change the traffic signals until the second zone does not detect vehicles. As explained, suitably information from the second zone may be conveniently communicated via a barrier interface that forms part of a traffic signals, traffic signal controller.

In exemplary embodiments, the sensor system comprises at least one sensor associated with each traffic signal head of the first set of traffic signals. Here, each sensor is configured to monitor a first zone and a second zone. Preferably, each traffic signal head of the first set of traffic signal heads comprises a plurality of sensors, wherein one sensor monitors the first zone and a separate sensor monitors the second zone. Thus, in the exemplary embodiments, each traffic signal head in the first set of traffic signal heads comprises a first sensor configured to detect vehicles travelling towards the traffic signal head (with respect to the direction of the head) and a second sensor configured to detect vehicles exiting a second zone behind the traffic signal head (with respect to the direction of the head). Suitably, each sensor forms part of a traffic signal.

As will be appreciated, suitably the first set of traffic signal heads comprises at least a first traffic signal to one side of the junction and at least a second traffic signal to the other side. However, as is known, further traffic signals may be required or desirable to each side to ensure the traffic can adequately see a traffic signal when approaching the junction. Here, where multiple traffic signals are installed to one side of the junction, it is envisaged each traffic signal will include a vehicle sensor to monitor a first zone (forward) and a second zone (rearward). Consequently, the first zone of the haul route approaching one side of the junction may be comprised of a combined area covered by the first zones of each traffic signal.

That is, if first and second traffic signals are used to one side of the junction, the 'call for green' signal may be decided when a vehicle enters either of the first zones of the respective first and second traffic signals. Likewise, the 'all red' signal wherein the traffic system does not change may be held until both the second zones of the first and second traffic signals are clear. In preferable embodiments, the sensors of the sensor system associated with the first set of traffic signal heads are controllable to configure the areas of the respective zones to optimally cover the approach to the signals or the junction. Where each traffic signal comprises a first and second sensor to separately monitor the first and second zones, the sensors may be adjustably attached to the traffic signal (i.e. the pole of the traffic signal) so that the zones can be adjusted by manually directing the sensors. Each sensor may also be configurable to adjust the angle of the zone.

In the exemplary embodiments, the system has a single second zone. That is, where the first set of traffic signal heads comprises at least one traffic signal to one side of the junction and at least a second traffic signal to the other side, the second zone is comprised of the combined area covered by the second zones of the sensors on all of the traffic signals forming part of the first set of heads. In contrast, there will be a first zone forward of the traffic signals to one side (formed of a combined zone of two traffic signals where the system is configured with multiple traffic signals to that side) and a separate first zone forward of the traffic signals to the other side (formed of a combined zone of two traffic signals where the system is configured with multiple traffic signals to that side). It will be appreciated that the two first zones will be opposed to each other to detect vehicles approaching the junction form the opposed directions.

In some exemplary embodiments, the first traffic signal set may include further operational features such as one or more cameras. The one or more cameras can be configured to record video footage of the crossing and additionally or alternatively to provide number plate recognition functionality. One or both of which may be used to further automate the regulatory requirements of a haul route junction. Consequently, there is provided a portable traffic signal for use in the traffic management system, wherein the portable traffic signal comprises a base, a post supported by the base, a traffic signal head supported by the post, a forward sensor and a rearward sensor, wherein the forward sensor is configured to detect vehicles in the first zone associated with the traffic signal head and the rearward sensor is configured to detect vehicles in the second zone associated with the traffic signal head. The traffic signal may have a plurality of traffic signal heads. Here, one or more of the traffic signal heads form the or part of the first set of traffic signal heads. Optionally, one or more of the plurality of traffic signal heads may form the second set of traffic signal heads.

In exemplary embodiments, the second set of traffic signal heads may be configured as is known in the art to control the flow of traffic along the second phase (main road). For instance, the second set of traffic signal heads may comprise a plurality of traffic signals with one or more traffic signals arranged to each side of the junction. It is envisaged in some instances that some of the second set of traffic signal heads can be provided on the traffic signal associated with heads of the first set. Suitably, the second set of traffic signal heads may be comprised as slave traffic signals within the system as herein described. Moreover, the second set of traffic signal heads may include forward vehicle detectors as part of the sensor system to provide information to the master traffic signal controller regarding traffic approaching or waiting at the signals of the second phase. Optionally, the traffic signals of the second traffic signal set may be substantially the same as the first traffic signal set. Here, optionally, the second traffic signal set may also have a second zone to detect vehicles behind the traffic signal and to provide further coverage for the common second zone.

Optionally, the traffic management system may include a variable messaging sign. The variable messaging sign can be used to warn vehicles travelling along the main road (second phase) that the signals on the main road are red (i.e. stop) or are about to begin turning to red (because a vehicle has been detected approaching a first zone of the first set of traffic lights triggering a 'call to green' on the haul route.

In the exemplary embodiments, the traffic management system is configured to operate a control algorithm to control the system to carry out the following steps. Thus, in the exemplary embodiments, the traffic management system comprises a control system for controlling the components of the system to operate the desired algorithm (i.e. process flow). It will be appreciated from the foregoing that the control system therefore suitably and optionally comprises one or more of the barrier control, traffic signal controllers including one or both of the barrier interface and the traffic signal interface, wherein the traffic signal controller include a master traffic signal controller and one or more slave traffic signal controllers. There is therefore further provided a method of controlling a traffic management system to complete the following steps (process flow that the control system is configured to complete). The steps will be described staring from the traffic management system for the haul route junction being configured to allow traffic to flow along the main road (second phase). Here, the traffic management system is configured with the second set of traffic signal heads displaying a proceed signal (i.e. a green light) and the first set of traffic signal heads displaying a stop signal (red light) with the barrier system configured in a closed position to at least partially obstruct the haul route (first phase). Upon a vehicle entering a first zone of the first set of traffic signal heads, the second set of traffic signal heads complete the step of stopping traffic along the second phase. For instance, by transifioning the second set of traffic signal heads to display a stop sign (i.e. red light). Once the second set of traffic signal heads display a stop signal, the barrier system is configured to complete the step of moving from a closed position to an open position. Also, after the second set of traffic signal heads display a stop sign, and preferably once the barrier system is in the open position, the first set of traffic signal heads complete the step of transitioning from a stop signal to a proceed signal (i.e. green light). After a predetermined time, or after the first zones of the first set of traffic signal heads are clear, the first set of traffic signal heads are configured to complete a step of transitioning from the proceed signal (green light) to the stop signal (red light). However, the barrier system is not configured to complete the step of moving from the open position to the closed position until the second zone is detected as being clear of vehicles. Once the system confirms that the second zone is clear, the barrier system is configured to complete the step of moving to the closed position. Once the barrier system is in the closed position, the first set of traffic signal heads are configured to complete the step of transitioning from the stop signal (red light) to the proceed signal (green light). It will be appreciated that the sequence of steps can then be repeated. And also, the sequence of steps could equally start from any step in the cycle.

Optionally, the steps may include determining if a vehicle is within the second zone a first predetermined time after the first set of traffic signal heads display a stop signal, and if the control system determines a vehicle is detected within the second zone, a further step of determining if a vehicle is within the second zone a second predetermined time after the end of the first predetermined time. Thus the first predetermined period can be set to be a minimum period for a vehicle to clear the junction, and the main road being halted on a stop signal can be minimised, whilst maintaining safety by extending the period if the second zone remains blocked, for instance by a slower moving vehicle. Also, if a vehicle is detected within the second zone at the end of the second predetermined time, the process flow of the control system can suitably be configured to determine if a vehicle is within the second zone a third and successive predetermined periods after the end of said period. The second predetermined period can be shorter than the first. The third predetermined period may be the same as the second or may be progressively shorter. Because the control system is configured to change the barrier system to the closed arrangement when a vehicle is not detected in the second zone, safety is improved.

Suitably, when the control system determines a vehicle is detected in the first zone, the control system is configured to determine if a vehicle is approaching the second set of traffic signal heads and if no traffic is detected approaching the second set of traffic signal heads, the control system is configured to complete the step of controlling the second set of traffic signals to change from a proceed signal to a stop signal. Suitably, if traffic is detected approaching the second set of traffic signal heads, the control system is configured to control the second set of traffic signals to change from a proceed signal to a stop signal after a predetermined time or, if earlier, when no traffic is detected approaching the second set of traffic signal heads.

The step of changing the first set of traffic signal heads to display a stop signal, suitably comprises displaying the stop signal a predetermined time after changing to display a proceed signal, wherein the predetermined time is extended if the control system determines a vehicle is detected in the first zone.

Thus, the predetermined time can be configured to allow a vehicle to clear the first zone, for instance a relatively fast moving vehicle, but to maintain safety the period can be extended for a slower moving vehicle or for a column of site traffic.

The control system can preferably be configured to open the barrier system before the control system is configured to change the first set of traffic signal heads to display the proceed signal.

Advantageously, because the step of closing the barrier system after haul route traffic has cleared the second zone of the junction is dependent on the 'all red' signal being clear (i.e. the sensor system not detecting vehicles in the second zone), the system can be configured to open the main road (second phase) sooner than when the system is configured to stay red for a predetermined time based on the slowest expected site vehicle crossing time.

The step of closing the barrier system may comprise using signal data from the second zone to detect whether the crossing is clear, as is known in the art, and after a predetermined time, but the predetermined time may be configured to be the shortest (quickest) expected crossing time of a site vehicle. That is the length of time it might take a relatively quick moving site vehicle to cross. Here, if the signals from the second zone indicate a vehicle is still within the second zone, the system is configured to extend the period of the red signal on the main road for a further period. At the end of the extended period, the system can be configured to detect whether the crossing is clear and if it is complete the step of closing the barrier system, or if it is still not clear, extend the red period of the main road for a further period. This can be repeated until the second zone is clear.

The step of the first set of traffic signal heads transitioning from the proceed signal (green light) to the stop signal (red light) can be configured to start after a predetermined time. That is, after the first set of traffic signal heads detects a vehicle in a first zone and the heads transition to a proceed signal, the first set of traffic signal heads are configured to remain displaying the proceed signal (green light) for a predetermined time. The predetermined time may be configured as the expected time for one vehicle to move through the signal. In exemplary embodiments, the predetermined time can be extended for one or more further periods if a vehicle is detected in a first zone (i.e. because there was a column of traffic waiting on the haul route, or if a vehicle approaches the junction in the opposite direction of the haul route). The period of time the first set of traffic signals displays a proceed signal may preferably be set not to exceed a maximum period. That is, after the maximum period, the first set of traffic signals is configured to complete the step of transitioning the stop signal, even if vehicles are detected in a first zone.

Suitably, the system is configured so that the second set of signals display the proceed signal unless a vehicle is detected in a first zone of the first set of signals. Upon detecting a vehicle entering a first zone, the system is suitably configured to determine if vehicles are detected in a forward zone of the second set of traffic signal heads. That is, to determine whether traffic is flowing along the main road or traffic is approaching the second heads. If no traffic along the main road is detected, the system is configured to complete the step of transitioning the second set of signal heads from the proceed signal to the stop signal. If traffic is detected, the system is suitably configured to remain displaying the proceed signal on the second set of heads up to a predetermined time or until no traffic along the main road is detected.

In exemplary embodiments wherein the system includes a messaging sign, the messaging sign may be activated to display a warning when the barriers are open. For instance, the messaging sign can display a warning for vehicles to slow when the barrier is open and traffic along the main road is stopped.

II

The invention includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

Summary of the Figures

Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures in which: Figure 1 shows an acknowledged art haul route crossing; Figure 2. shows a typical haul route crossing with a traffic management system according to the exemplary embodiments; Figure 3 shows a suitable barrier for the exemplary traffic management system; Figure 4 shows a suitable traffic signal for the exemplary traffic management system; Figure 5 shows the traffic management system of figure 3 highlighting first detection zones; Figure 6 shows the traffic management system of figure 3 highlighting second detection zones; Figure 7 shows an optional messaging sign for use with the traffic management system; and Figure 8 shows an exemplary method flow chart of the steps the exemplary traffic management system 15 completes.

Detailed Description of the Invention

Aspects and embodiments of the exemplary embodiments will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

Referring to Figure 2 a traffic management system 10 is shown arranged at a haul route junction, wherein a main road 20 is intersected by a temporary haul route 30. The system comprises a barrier system 100, a first set of traffic signal heads 200 and a second set of traffic signal heads 300. The barrier system is shown as comprising four barriers (A', B', C', D'). The first set of traffic signal heads are shown as comprising two traffic signals (A, B) to one side of the junction and two traffic signals (C, D) to the other side of the junction. The second set of traffic signal heads is shown as comprising two traffic signals (S1, S2) to one side and two traffic signals (S3, S4) to the other side. Therefore, whilst a traffic signal may have multiple heads from the same set or multiple heads with at least one head from each set, each traffic signal shown in the figures comprises a single head and consequently the first set of traffic signal heads corresponds to a first set of traffic signals. Likewise, the second set of traffic signal heads corresponds to a second set of traffic signals.

Referring to Figure 3, an exemplary barrier 100 is shown. It will be appreciated that the barrier may comprise each of the four barriers shown in the example of Figure 3. The barrier 100 comprises a base 110 and a connected arm 120. The arm is moveable relative to the base between a closed position 120' and an open position 120". The base houses a motor to control the movement between the open and closed positions as well as a barrier control that provides the control of the barrier's arm and to provide an interface to communicate with the other components of the system so that the status of the barrier can be sent to other components of the system and so that the barrier can receive from other components of the system control input to actuate the change between the open and closed positions. So called swing arm barriers, are known in the art. But the application to haul route crossing has not been proposed before.

Referring to Figure 4, an exemplary traffic signal 200 is shown. The traffic signal comprises base 210 that provides ballast and provides the portability of the traffic signal so as to enable the barrier to be moved between sites and crossings. The base also provides convenient housing for the traffic signal controller 212. The traffic signal controller 212 comprises the functionality of a traffic signal interface 214 and a barrier interface 216. A post 220 is connected to the base and supports a traffic signal head 230.

As is known, the traffic signal head comprises signals and typically red, amber and green lights that can be controlled by the traffic signal controller as is known in the art. As will be herein described, one of the traffic signals is a master signal and the remainder are slave signals. Consequently, the traffic signal comprises a transceiver 240 for communicating wirelessly with the other components in the system.

Including to transmit and receive driving signals and to transmit or receive status information. These features are common to the traffic signals in both the first set of traffic signal heads and the second set of traffic signal heads and are functions known on existing traffic signals. Furthermore, the traffic signals in the first set of traffic signal heads and preferably also the second set of traffic signal heads include a forward-facing detector 250. The forward-facing detector forms part of a sensor system of the traffic management system 10.

The forward-facing detector 250 is configured to detect vehicles approaching the traffic signal and entering a first zone. As is known in the art, when the forward-facing detector detects an approaching vehicle, the system is configured to use the signal in the control of the crossing. For instance, to indicate that the system should change the flow of traffic from one phase to another or to prevent the crossing from changing phase because traffic remains approaching along one phase. The forward-facing detector 250 communicates with the traffic signal interface, which is part of the traffic signal controller.

Referring to Figure 4, the traffic signal is shown as also comprising a rearward facing detector 250 that forms part of the sensor system and communicates with the barrier interface 216, which is part of the traffic signal controller. These are envisaged as being functional features only on the traffic signals including part of the first set of traffic signal heads. The rearward facing detector 260 detects vehicles within a second zone. The second zone is configured to be an area covering the crossing. The barrier interface communicates with an associated barrier, and is responsible for sending opening and closing commands.

The detection sensors (i.e. forward or rearward) can be radar, ultrasonic, optic infrared, sonar, magnetic, LIDAR detection means, or other cameras. The forward and rearward detection sensors do not have to have the same detection means but can be different types of sensors. For example, one can be a radar, the other an optical sensor. A preferred rearward detection sensor is ADS Detector.

As will be appreciated, the first zone and the second zone of one traffic signal are substantially in opposing directions. The First zone detected by the vehicle detection sensor (first sensor) is arranged to cover the area in front of the traffic signal (detect plant upstream of the direction of haul route traffic). The second zone detected by the second detection sensor (all red detection) is arranged to cover an area behind the traffic signal (detect plant downstream of the direction of haul route traffic and intersection of the junction).

The first detection sensor (forward vehicle detection) is in communication with the traffic signal interface 214 and the second detection sensor (rearward all red detection) is in communication with the barrier interface. The all-red detector is suitably configured to detect moving objects in the second zone from 4kph. The all-red detector transmits the detection information as a digital output to the barrier interface.

Referring to Figure 5, the two traffic signals (A, B) to one side of the junction form a first zone Z1' comprised of the combined area of the forward-facing sensor 250 on traffic signal A and the forward-facing sensor 250 on traffic signal B. Likewise, a separate first zone Z1" is formed on the other side of the junction by the combined areas of the forward-facing sensors on traffic signals C and D. Traffic approaching the junction 20 along the haul route will enter one of the first zones. The forward-facing sensors are suitably adjustably mounted to the posts (or other part of the traffic signal) so that the area of the respective first zone can be controlled. Thus, the first zone can be optimised. For instance, with two overlapping first zones from respective traffic signals.

Referring to Figure 6, the rearward facing sensors of all four traffic signals create a combined second zone Z2. Again, the rearward facing sensors are adjustably mounted so that the respective second zone Z2 can be optimally configured. That is, so that the combined area Z2 of the respective second zones cover a substantial portion of the intersection between the traffic signals and the barriers.

Figure 7 shows an optional variable messaging sign 300 that can be incorporated in the system. For instance, the variable messaging sign can be located upstream of the junction and on the main road so as to warn drivers along the main road that traffic is crossing the haul route and that the main road has a stop signal ahead. That is, as explained herein, the variable messaging sign can be used to display an optional 'slow down' warning when the barriers are open.

One of the traffic signals forming the first set of traffic signal heads is configured as a master traffic signal.

Here, the control of the traffic management system is centralised on the traffic signal controller of the master traffic signal (i.e. a master traffic signal controller). However, some of the control functionality can be distributed across other components of the system. The master traffic signal controller runs the algorithm to control the system and transmits signals to slave traffic signals to control respective heads of the first and second sets. The master traffic controller can also include a barrier interface that communicates to all barriers or the barrier interfaces can be distributed on the slave traffic signals (including one on the master traffic signal to control any barriers associated with the master). The master slave relationship between traffic controllers is known.

Figure 8 explains the method steps that the exemplary traffic management system completes. Starting from Si wherein the main road displays a proceed signal. Here, the second set of traffic signal heads are controlled to display a stop sign and the barriers are all in the closed positions. Because the main road is required to have priority and disruption to the flow along the main road is required to be minimised, the system stays in this configuration until site traffic approaches the junction along the haul route. For instance, by the sensor system detecting a vehicle entering a first zone of the first set of traffic signal heads. For example, it could be from either side of the junction.

At 32, the system is configured to detect whether vehicles are detected approaching the second set of traffic signal heads. Again, from either direction, based on whether the forward-facing sensors of the second set of traffic signal heads detect a vehicle. If vehicles are not detected when plant on the haul route are detected, the system enters step S3 wherein the second set of traffic signal heads on the main road transition to a stop signal and the barriers are activated to begin to lift. If vehicles are detected along the main road, because the main road is required to have priority, the system is suitably configured to maintain the proceed signal on the main road for up to a predetermined period. At the end of the predetermined period or when vehicles are not detected by the forward-facing sensors of the second set of traffic signals, the system enters S3.

Between 32 and 33, the second set of traffic signal heads are controlled to transition from a proceed signal (green light) to a stop signal (red light) as is known. Once the system has confirmed that the second set of traffic signal heads are in the stop configuration, the barrier is controlled to lift from the closed position to the open position. Optionally the variable messaging sign is also activated.

Once the system has confirmed that the barriers are in the open position, in S4, the first set of traffic signal heads are controlled to transition from the stop signal (red light) to the proceed signal (green light).

The proceed signal on the haul route is held for a predetermined time, suitably 7 seconds. The predetermined can be extended up to a maximum period if at the end of the predetermined time vehicles are still detected in first zones of the first set of traffic signals.

At the end of the predetermined period of time or the extended or further extended period, in step 35, the traffic signal heads in the first set of traffic signal heads are controlled to transition from a proceed signal to a stop signal (green to red). The traffic signals in both sets of traffic signal heads now display a stop signal (an all red period). As explained herein, the all-red period with the barriers open is configured to stay until the junction is clear as determined by the second zone being clear of traffic. That is, the rearward facing sensors of the sensor system determining that no vehicles are in the second zone. Thus, after a predetermined period, the system is configured to analyse signals from the rearward sensors to determine if vehicles are within the second zone. If they are not, the system is configured to move to step S6. If they are, the all-red period is extended. After the extended period the rearward facing sensors are again checked so that the barriers are not controlled to close until vehicles have cleared the junction and do not therefore become trapped.

In step S6, and once the system has determined that the second zone is clear of vehicles, the barriers are controlled to move to the closed position. Once the system has confirmed that the barriers are closed and that the first set of traffic signal heads display a stop sign, the second set of traffic signal heads are controlled to transition from the stop signal to a proceed signal (red to green) and step 31 is repeated.

Whilst the barrier system consisting of a plurality of barriers have been described wherein all the barriers open and close simultaneously, it is envisaged the barriers may operate at phased intervals. For instance, a barrier on the entrance to the junction may be configured to close before the barrier on the exit. In particular, the barrier on the entrance may be configured to close before the second zone is clear.

Thus, the barrier not closing before the second zone is clear may include one of a plurality of barriers closing as long as at least one (and preferably all the barriers) on the exit from the junction do not close. Thus, allowing vehicles to clear the junction in their direction of travel.

Consequently, the traffic management system and method of operating a traffic management system at a haul route junction disclosed herein provides an improved safety function. Firstly, because the combination of the traffic signals with an automatic barrier system prevents highway traffic from inadvertently turning into the haul route and also provides an enhanced indication to the haul traffic when it is safe or not to cross that is less likely to be overlooked than a traffic signal alone. Secondly, because the combination of the barrier system and second detection zone at a rear of the traffic signals prevents the barriers closing and trapping vehicles between the barriers and also optimises the 'all red' period so that the main road is stopped for a minimum amount of time.

The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention. For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader.

The inventors do not wish to be bound by any of these theoretical explanations. Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

Throughout this specification, including the claims which follow, unless the context requires otherwise, the word "comprise" and "include", and variations such as "comprises", "comprising", and "including" will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in relation to a numerical value is optional and means for example +/-10%.

Claims (15)

1. Claims: 1. A portable traffic management system comprising a barrier system controllable to open and close a first phase, a first set of traffic signal heads on the first phase, a second set of traffic signal heads on a second phase, a detection system, and a control system, wherein the detection system is configured to detect vehicles in a first zone, the first zone being configured to be in a forward direction relative to the first set of traffic signal heads in order to detect vehicles approaching the first set of traffic signal heads, and the control system being configured to control the first and second sets of traffic signal heads to change from providing a proceed signal on the second set of traffic signal heads and a stop signal on the first set of traffic signal heads to display a stop signal on the second set of traffic signal heads and a proceed signal on the first set of traffic signal heads based on detecting a vehicle in the first zone; characterised in that the control system is configured to control the barrier system to change from a closed position to an open position when changing the first and second sets of traffic signal heads to display a proceed signal on the first set of traffic signal heads; the detection system is configured to detect vehicles in a second zone, the second zone being configured to be in a rearward direction relative to the first set of traffic signal heads in order to detect vehicles clearing a junction behind the traffic signal set; and the control system is further configured to control the first and second sets of traffic signal heads to change from providing a stop signal on the second set of traffic signal heads and a proceed signal on the first set of traffic signal heads to display a proceed signal on the second set of traffic signal heads and a stop signal on the first set of traffic signal heads and to change the barrier system from an open arrangement to a closed arrangement based on not detecting a vehicle in the first zone.
2. 2. The portable traffic management system of claim 1, wherein the control system is configured to determine if a vehicle is within the second zone a first predetermined time after the first set of traffic signal heads display a stop signal, and if the control system determines a vehicle is detected within the second zone, to determine if a vehicle is within the second zone a second predetermined time after the end of the first predetermined time.
3. 3. The portable traffic management system of claim 2, wherein if a vehicle is detected within the second zone at the end of the second predetermined time, the control system is configured to determine if a vehicle is within the second zone a third and successive predetermined periods after the end of said period.
4. 4. The portable traffic management system of claim 2 or 3, wherein the control system is configured to change the barrier system to the closed arrangement when a vehicle is not detected in the second zone.
5. 5. The portable traffic management system of any of claims 1 to 4, wherein when the control system determines a vehicle is detected in the first zone, the control system is configured to determine if a vehicle is approaching the second set of traffic signal heads and; if no traffic is detected approaching the second set of traffic signal heads, to control the second set of traffic signals to change from a proceed signal to a stop signal; or if traffic is detected approaching the second set of traffic signal heads, to control the second set of traffic signals to change from a proceed signal to a stop signal after a predetermined time or if earlier, when no traffic approaching the second set of traffic signal heads is detected.
6. 6. The portable traffic management system of any of claims 1 to 5, wherein the control system is configured to change the first set of traffic signal heads to display a stop signal a predetermined time after changing to display a proceed signal, wherein the predetermined time is extended if the control system determines a vehicle is detected in the first zone.
7. 7. The portable traffic management system of any of claims 1 to 6, wherein the control system is configured to change the barrier system from the closed arrangement to the open arrangement before the control system is configured to change the first set of traffic signal heads from displaying the stop signal to display the proceed signal.
8. 8. A method of a traffic management control for a haul route junction, the method comprising: displaying a stop signal on a first set of traffic signal heads, displaying a proceed signal on a second set of traffic signal heads and controlling a barrier system to be in a closed arrangement to obstruct a first phase associated with the first set of traffic signal heads detecting a vehicle in a first zone in a forward direction of the first set of traffic signal heads; subsequently, changing the second set of traffic signal heads to display a stop signal; subsequently, opening the barrier system and displaying a proceed signal on the first set of traffic signal heads; subsequently, displaying a stop signal on the first set of traffic signal heads; and determining if a vehicle is detected in a second zone in a rearward direction of the first set of traffic signal heads and when a vehicle is not detected in the second zone, closing the barrier system.
9. 9. The method of claim 8, wherein the step of determining if a vehicle is detected in the second zone comprises determining if a vehicle is within the second zone a first predetermined time after the first set of traffic signal heads display a stop signal, and if a vehicle is detected within the second zone, determining if a vehicle is within the second zone a second predetermined time after the end of the first predetermined time.
10. 10. The method of claim 9, wherein if a vehicle is detected within the second zone at the end of the second predetermined time, determining if a vehicle is within the second zone a third and successive predetermined periods after the end of said period.
11. 11. The method of any of claims 8 to 10, wherein subsequent to detecting a vehicle in the first zone, the method comprises determining if a vehicle is approaching the second set of traffic signal heads and; if no traffic is detected approaching the second set of traffic signal heads, changing the second set of traffic signal heads from displaying a proceed signal to a stop signal; or if traffic is detected approaching the second set of traffic signal heads, changing the second set of traffic signals to display a stop signal after a predetermined time or, if earlier, when no traffic id detected approaching the second set of traffic signal heads.
12. 12. The portable traffic management system of any of claims 8 to 11, wherein the step of changing the first set of traffic signal heads to display a stop signal, comprises changing the first set of traffic signal heads to display a stop signal a predetermined time after changing to display a proceed signal, and extending the predetermined time for further periods if a vehicle is detected in the first zone.
13. 13. The method of any of claims 8 to 12, wherein the step of opening the barrier system is completed before the step of displaying the proceed signal on the first set of traffic signal heads.
14. 14. The method of any of claims 8 to 13, wherein the method incudes the further steps of operating a variable display upstream of the haul route junction to operate a display when the barrier system is in the open arrangement.
15. 15. A portable traffic signal for use in the traffic management system of any of claims 1 to 7, wherein the portable traffic signal comprises a base, a post supported by the base, a traffic signal head supported by the post, a forward sensor and a rearward sensor, wherein the forward sensor is configured to detect vehicles in a first zone associated with the traffic signal head and the rearward sensor is configured to detect vehicles in a second zone associated with the traffic signal head.