Mobile pedestrian or vehicle position synchronization signal device and method

Abstract

The present application relates to systems and methods for transmitting visibility enhancement or warning signals from a moving group of pedestrians or vehicles. A position indicating device is disclosed, the position indicating device being operable when undergoing motion with a plurality of other position indicating devices, the position indicating device comprising: at least one transmitter that transmits a position indicating signal; a receiver; a power source; and an electronic circuit system configured and programmed to: a) receive synchronization signals from other position indicating devices located within a synchronization range of the device via the receiver; and b) in response to receiving one or more synchronization signals from one or more other position indicating devices located within the synchronization range, cause the at least one transmitter to transmit a signal that is synchronized with the signals transmitted by the one or more other position indicating devices located within the synchronization range.

Description

[0001] Related applications

[0002] This application is a divisional application of Application No. 201880057575.3, entitled "Mobile Pedestrian or Vehicle Position Synchronized Signal Apparatus and Method." This application claims priority to U.S. Provisional Patent Application No. 62 / 529,423, filed on July 6, 2017, entitled "Synchronized Behavior of Bicycle, Motorcycle, and Pedestrian Warning Devices," the entire disclosure of which is expressly incorporated herein by reference. Technical Field

[0003] The present invention relates generally to the fields of electronics and traffic engineering, and more particularly to systems and methods for transmitting visibility enhancement or warning signals from a moving group of pedestrians or vehicles. Background Art

[0004] Pursuant to 37 CFR 1.71(e), this patent document contains material that is subject to copyright protection and all copyrights are reserved by the owner of this patent document.

[0005] Pedestrians (e.g., runners, joggers, walkers, etc.) and occupants of certain vehicles (e.g., cyclists, motorcyclists, drivers of slower or vulnerable vehicles) are easily injured by vehicle collisions. These pedestrians and vehicles sometimes travel or move along a highway in groups of two or more. For example, a group of cyclists may include 20 to 50 or more riders. When deployed along the direction of travel in the early morning or evening, the headlights and / or taillights attached to the bicycles may flash to warn approaching motor vehicle drivers. However, for approaching vehicle drivers, this may look like randomly flashing lights from a distance, and the overall size of the group cannot be clearly understood by oncoming drivers.

[0006] Existing warning lights mounted on bicycles, motorcycles, and other moving vehicles flash to warn approaching drivers. Individual flashes of forward or reverse lights have limited energy, and therefore, the visual light output is limited due to the available power and reflector surface area. Improvements in light source efficiency (LEDs vs. incandescents), sophisticated optics, and improvements in battery technology have resulted in better warning lights. However, injuries from collisions continue and are becoming more frequent. Improvements in the optics, power, and efficiency of warning lights are needed. Pedestrians walking along the roadside suffer the same injuries. For example, on a winter morning, a group of children walking to school can be difficult to see in the dark. Flashing lights on these pedestrians' backpacks, helmets, shoes, or clothing can make them more visible to oncoming drivers.

[0007] According to the present invention, when several pedestrians or vehicles are moving in a group, such flashing lights may flash synchronously or in unison, or illuminate in other ways synchronously or in unison (e.g., solid non-flashing, pattern flashing, etc.), thereby enhancing the perceived brightness and size of the emitted light and making the group more visible to oncoming traffic. Summary of the Invention

[0008] According to one aspect of the present disclosure, there is provided a position indicating device that transmits a synchronized position indicating signal when moving within a specific distance range (ie, a synchronization range) of other mobile devices of such mobile devices. In some embodiments, these devices can be in the form of an electronic flasher that emits a flash of light or other signal, examples of which are described in U.S. Patent Nos. 7,088,222; 7,106,179; 8,154,424; 8,550,653; 8,564,456; 8,579,460; 9,288,088; 9,835,319; D510,289; D515,957; D515,958; D560,533; D654,387; D669,805; D778,752 and D778,753 and U.S. Patent Application Publication Nos. 2013 / 0113634; 2016 / 0186971 and pending U.S. Patent Application Serial No. 15 / 893,420, the entire disclosure of each such patent and application being expressly incorporated herein by reference. In some embodiments, these devices can be attached to or integrated / manufactured in a vehicle, vehicle accessory, or other object, such as a vehicle, bicycle, bicycle seat, bicycle light, motorcycle, motorbike, wearable clothing, vest, shoe, running shoe, headwear, hat, helmet, hard hat, strap, leg strap, arm strap, belt, backpack, lanyard, jewelry, earrings, necklace, and wristband.

[0009] According to another aspect of the present disclosure, a position indicating device is provided that is operable when moved with other such devices, wherein each such device includes: at least one transmitter that transmits a position indicating signal; a radio or other receiver (which may also include a transmitter); a power source; and an electronic circuit system that is configured and programmed to a) receive synchronization signals from other position indicating devices located within a synchronization range of the device via the receiver; and b) in response to receiving one or more synchronization signals from one or more other position indicating devices located within the synchronization range, cause the at least one transmitter to transmit a signal that is synchronized with the signal transmitted by the one or more other position indicating devices located within the synchronization range.

[0010] According to another aspect of the present disclosure, a method for using multiple position indicating devices to indicate the positions of multiple moving pedestrians or vehicles is provided, the method including the steps of equipping each of the pedestrians or vehicles with at least one of the devices, each of the devices including a transmitter for transmitting a position indicating signal and a control device, the control device being programmed to i) sense when the device is within the synchronization range of one or more other devices, and when it is within the synchronization distance range of one or more other devices, and ii) cause the transmitter of the device to transmit a position indicating signal, which is synchronized with the position indicating signal transmitted by the one or more other devices located within the synchronization range.

[0011] Other aspects and details of the present invention will be understood by reading the detailed description and examples set forth below. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The following detailed description and examples are provided for the purpose of describing some, but not necessarily all, examples or embodiments of the invention in a non-exhaustive manner and are not intended to limit the scope of the invention in any way.

[0013] Figure 1 is a diagram showing elements of one embodiment of the position indicating device of the present invention.

[0014] Figure 2 is a diagram of an embodiment of the system of the present invention, the system includes multiple Figure 1 The position indicating devices shown in are attached to or carried by pedestrians or vehicles moving along a road or other thoroughfare.

[0015] Figure 3 is a diagram illustrating one non-limiting example of an operating protocol by which the position indicating device of the present invention may be programmed to operate.

[0016] Figure 4 is a diagram illustrating a protocol by which the position indicating device of the present invention may be programmed to distinguish between individual pedestrians or groups of vehicles passing or approaching each other.

[0017] Figure 5 is a diagram illustrating one non-limiting example of a mesh network or "master-slave" network that may be used in the apparatus of the present invention. DETAILED DESCRIPTION

[0018] The following detailed description and the accompanying drawings are intended to describe some, but not necessarily all, examples or embodiments of the present invention. The described embodiments should be considered in all respects to be merely illustrative and not restrictive. The content of this detailed description and the accompanying drawings does not limit the scope of the present invention in any way.

[0019] When several cyclists are riding on the side of the road, their warning lights may become mixed with ambient and infrastructure lights that serve multiple purposes. For example, lights emitted from store fronts, cars at intersections, retail buildings, etc., can obscure the flashing warning lights of the cyclists. In addition, when vehicles attempt to pass through a group (such as a funeral procession, a convoy of military vehicles, etc.), it is sometimes difficult for other vehicles traveling on the same road to visually perceive the presence or extent of such a group. The present invention provides signaling devices and systems that can be embodied, held, carried, worn, or affixed to such pedestrians or vehicles and that are programmed to emit synchronized position indicating signals when such pedestrians or vehicles are moving in a group, thereby facilitating visibility and perception of the group.

[0020] In another non-limiting example, the present invention provides a means of enhancing or increasing the safety features of bicycle or motorcycle lighting. The multiplication factor is simply the number of cyclists in a group (cluster). Currently, each flashing light provides a portion of the group's total available battery energy and light output when not coordinated with the light output of the other members of the group. By providing coordination of the individual flashing lights, the "cluster" will appear as a larger, brighter entity, providing safety that cannot be provided by multiple independently flashing bicycle warning lights.

[0021] The present invention addresses the advantages provided by coordinating the flashing of a large number of individually flashing safety lights on a group of mobile nodes (e.g., bicycles, motorcycles, RVs, roadside walkers or joggers, etc.) By coordinating the flashing of the LED lights on the individual nodes, the "group" appears larger and more unique, thereby providing safety advantages.

[0022] Using radio, infrared or acoustic communications, mesh networks, master-slave or hybrid communication networks, the previously independent flashing of lights on moving and non-connected vehicles or pedestrians can be coordinated so that all lights flash in unison, sequentially or in some other more easily visible pattern.

[0023] The present invention addresses the challenges associated with coordinating actions (e.g., flashing lights) between multiple different mobile entities. To provide dynamic location synchronization, the network must account for position changes and signal strength variations due to multipath reflections from cars, trucks, and bicycles. Furthermore, flashing all lights simultaneously requires network coordination, timing, and the ability to dynamically number network nodes that leave and join the network.

[0024] Figure 1 An example of basic elements that may be included in the position indicating device 12 of the present invention is shown. Figure 2An example of a system (eg, a network or group) is shown that includes a plurality of position indicating devices 12a through 12f (eg, each device representing an individual "node") moving in a common direction along a road or other thoroughfare RW.

[0025] like Figure 1 As shown in , each device 12 includes at least one transmitter 16 (such as an LED, other light source, speaker, or the like) that transmits a position-indicating signal, a radio or other receiver 14 (which may also include a transmitter in some embodiments), a power source 20 (e.g., a battery or solar panel), and an electronic circuit system 18 (e.g., an integrated circuit having a controller). The electronic circuit system 18 is configured and programmed to receive synchronization signals from other such position-indicating devices 12 located within a synchronization range SR of the device 12 via the receiver 14, and, in response to receiving one or more synchronization signals from one or more other position-indicating devices 12 located within the synchronization range SR, cause the transmitter 16 to transmit a signal that is synchronized with the signals transmitted by the one or more other position-indicating devices 12a to 12f located within the synchronization range SR.

[0026] exist Figure 2 In the example shown in FIG, four of the six devices 12b, 12c, 12d, and 12e are within the synchronization range SR of each other. Therefore, devices 12b, 12c, 12d, and 12e all transmit synchronization position indicating signals. However, non-grouped devices 12a and 12f are currently outside the synchronization range SR of all other devices in the network or group. Therefore, devices 12a and 12f either do not transmit any signals or transmit signals that are different or not synchronized with the signals transmitted by grouped devices 12b, 12c, 12d, and 12e.

[0027] If one of the ungrouped devices 12a or 12f subsequently becomes located within the synchronization range SR of any of the grouped devices 12b, 12c, 12d or 12e, this device will automatically join the group and will adopt / start transmitting synchronization position indication signals together with the other grouped devices 12b, 12c, 12d and 12e.

[0028] If one of the grouped devices 12a, 12b, 12c, 12d moves outside the synchronization range SR of the group, then this device will stop transmitting the synchronized group position indication signal and will become stationary and not transmit any signal, or will adopt and start transmitting a different or non-synchronized position indication signal.

[0029] In some embodiments, the synchronized group position indication signals emitted by the grouped devices 12b, 12c, 12d, and 12e can be sequential in nature. For example, the flashes can be emitted sequentially from the first device 12b to the last device 12d, or from the last device 12d to the first device 12a. In such sequential embodiments, if the order of the grouped devices 12b, 12c, 12d, and 12e changes, the devices can be programmed to automatically reorder to maintain the desired first-to-last or last-to-first order, even if the actual order of the devices in the group has changed.

[0030] Mesh Network

[0031] When multiple bicycles or pedestrians or other vehicles using the same device are close to each other and within range of the radios, one of the radios must take control to initiate the coordination signal. However, this temporary master may quickly move out of range. Therefore, any other node (bicycle) must be able to take control. In addition, because all devices are programmed to be exactly the same, there is no predefined "master" or "slave". The network must be able to dynamically transfer control from each member to the next. Therefore, depending on the range and conflict issues, the network must act as both a master-slave and a mesh network. A novel aspect of the present invention is the dynamic conversion between mesh topology and master-slave topology. A fundamental aspect of this dynamic conversion is that when all nodes are not within range of another node, for example, a light flashes once per second. However, the two nodes may not flash in sync, even if each node flashes once per second. Once in range, each node will establish a "master" clock to synchronize the transmitted signal (e.g., flashing light).

[0032] refer to Figure 3An example operational scenario involves two nodes approaching within range. Each node, either randomly or in coordination with an LED flash, transmits a request control signal (Request Control Signal - RCS) and seeks confirmation. The first node to transmit the Request Control Signal takes control of the network. Upon receiving the Request Control Signal, the second node will a) acknowledge receipt and b) cease transmitting the Request Control Signal and simply enter receive and broadcast mode (mesh network). The second of the two nodes will flash according to the first node's instructions and timing (master-slave). Both nodes will begin issuing Network Establishment Signals (NES) in coordination with the LED flashes. The Network Establishment Signal will include flashing characteristics (timing, duration, frequency, etc.) and the number of nodes in the network. As other members of the group come into range, they will also transmit Request Control Signals with random timing. However, the first two nodes that have already established a network will not respond, but will continue flashing and transmitting Network Establishment Signals containing the number of nodes in the network. If a single new node moves within range, it will receive a Network Establishment Signal with a network size of 2. This Network Establishment Signal will trigger an confirmation, which will increase the network size to 3 nodes. The network size parameter will be propagated to all nodes in the network (mesh).

[0033] If a similar sequence of events occurs between an approaching group of cyclists who have already established a network, a potential conflict arises. The two groups that independently formed a network will send network establishment signals. However, one parameter is network size. For example, the network with the larger node count (which may be the smaller node count control) will control the smaller network. The smaller network will continue to send network establishment signals, but a) with a new node count that includes the sum of both groups; b) adopt the NES identifier of the larger group; and c) be consistent with the larger group.

[0034] Network mergers

[0035] refer to Figure 4, a group of nodes (e.g., cyclists) that have already formed a network (group) can now encounter another group of nodes that are also operating as a group. When a device in group 1 receives a network establishment signal (NES) from group 2, the member will compare the node count sent by group 2 with the node count sent from its own group 1. (The same applies to group 2 members). If the node count of group 2 is larger, the group 2 member that first receives the NES from group 1 will send a network authority (NIC) signal with the group 2 identifier. This signal will be relayed by any node in group 1 or group 2 to other nodes (mesh network) that are not within range of the initiating group 1 member. The NIC signal takes precedence over other commands. Once a group 1 or 2 member receives the NIC signal, they will all start sending network establishment signals (NES) with the group 2 identifier and the new node count (the sum of group 1 and group 2).

[0036] As other groups approach, a single group will be established using the same systematic approach. If the groups have the same number of nodes, the tiebreaker will be each node's unique identifier (similar to a MAC address). The node with the lower numerical unique identifier will gain control. In another embodiment, the node with the higher numerical identifier gains control.

[0037] Nodes flash simultaneously

[0038] In the system of the present invention, a mesh network or "master-slave" network can be used to coordinate timing. Other forms include GPS timing signals received via satellite, real-time clock modules, or cellular timing signals or timing signals from world time transmissions (e.g., WWV in Fort Collins, Colorado, or similar European or Asian government time broadcasts). The technical approach used involves establishing a common clock signal through the network. In order to make all lights in the network flash simultaneously, the new method described herein introduces a fixed delay between the sequence number in the network and the flashing of the light. For example, using a 10-light network, node 1 sends a signal to its closest neighbor, defining the timing signal. It then waits 900 milliseconds to flash its light. Node 2 hears the signal and waits 800 milliseconds to flash its light. Node 3 hears the signal and waits 700 milliseconds to flash its light. This continues until light 10 receives the clock signal and flashes immediately. Even without direct radio, infrared, ultrasonic, or other media communication, a lower number of lights will flash simultaneously. Based on this scheme, all 10 lights will flash simultaneously. If there are 11 lights in the system, node 11 will hear the signal from the other nodes, node 10, and delay its flashing by 900 milliseconds. It will flash at the same time as node 1, and the same as all other nodes.

[0039] The net effect is that all the lights will flash simultaneously, despite being out of range of all but one light; each light does not need to "hear" light number 1 or any other light number. Using an "incidence matrix" or neighbor table, each light can only hear 1 of the 8 closest lights; that is, any of the 4 lights numbered greater than N or any of the 4 lights numbered less than N.

[0040] This is shown in Table 1 below:

[0041] Table 1

[0042] Relation Table

[0043]

[0044] In the above incidence matrix, shown above by line b), light N receives information from three lights with lower sequence numbers and one light with a higher sequence number. Any of these lights can provide the necessary information for light N to obtain timing and flash delay data. Therefore, light N does not need to be within range of light 1.

[0045] To dynamically establish relative positioning, an "incidence matrix" or neighbor table is used to effectively define the presence or absence of neighboring nodes.

[0046] Sequential flashing

[0047] An alternative to having multiple moving nodes (bicycles, vehicles, pedestrians) flash their lights in unison is to have them flash sequentially from the last row to the first. This flashing pattern would present a dynamically flashing "arrow" to approaching motorists. To achieve this, each node must establish its physical location (position) relative to the other nodes. Furthermore, this location must change dynamically as one bicycle passes another, so that the nodes can be renumbered.

[0048] An alternative algorithm could use a combination of taillights and headlights to transmit sequence numbers from following nodes to leading nodes (e.g., bicycles). Connecting taillights and headlights would allow modulated signals to carry position and sequence information in the visible spectrum, infrared spectrum, high-frequency sound, or radio. The taillight and headlight of any bicycle, other vehicle, or pedestrian would communicate with each other via radio (e.g., Bluetooth, Wi-Fi), hardwired connections, sound, infrared light, etc. Thus, the node number would be transmitted to the physically closest leading node and the physically closest following node via visible light modulation, infrared light modulation, sound, or radio. The rearmost taillight would not receive the identification signal from behind and would therefore assume the sequence position at the end of the group. The headlight would transmit its position information to the next bicycle in line. This information would be received by the leading taillight (using a photodetector, phototransistor, photodiode, LED acting as a photodiode when not flashing, etc.). The next member would then transmit its position information to the node in front, and so on. This architecture would allow for rapid sequencing of multiple lights. When a mobile node (pedestrian, cyclist, vehicle) changes location, the new physical location is established via the node number sent and received from the taillights and headlights.

[0049] Master-Slave

[0050] Alternatively, depending on the size of the light's plastic housing and the length of the antenna, a lower frequency (longer range) radio signal could be used. This would allow for a simple "master-slave" system to be deployed, with one node (the bicycle) designated as the master and all other nodes as "slaves." At lower frequencies, the master node's range would be sufficient to control all slave nodes within a range of 2 kilometers or more.

[0051] Dynamic flashing mode

[0052] Once the individual nodes are "linked" via a mesh, master-slave, or hybrid network, the blinking rate and pattern of the LEDs can be dynamically controlled. For example, utilizing proximity detection using ultrasound, radar, laser reflections, headlight intensity, and the like, a vehicle approaching from behind the group can be sensed, and the blinking pattern altered by the microcontroller firmware embedded in the blinkers. Changes can include longer-duration blinking duty cycles, brighter blinks, faster blinks, and more. This alerts approaching drivers by providing dynamic patterns rather than a monotonous, continuous blinking pattern. For example, the simultaneous blinking of many bicycle taillights can increase in brightness and blinking rate as a vehicle approaches, ultimately becoming a "steady on," or steadily burning illumination, to make the cyclist most visible. Alternatively, the color of the blinking taillights can change from amber to red or green depending on the distance to the approaching vehicle. This dynamic response of the blinking pattern to approaching vehicles represents a novel and important safety feature.

[0053] Crowd synchronization behavior

[0054] Large groups of pedestrians (crowds) wearing devices that emit light, sound, or other forms of energy can be coordinated in a similar manner. Recent demonstrations of this type of crowd dynamic behavior have been seen in Olympic stadiums, where wristbands or headlights flash in different colors and patterns. However, in all these demonstrations, the coordination signal relies on infrastructure: an infrared or radio signal broadcast from a central location close to the crowd, typically within the crowd's line of sight. A "master" signal can be broadcast by several infrared light sources hardwired to a central control system. In the proposed invention, coordination of crowd node behavior requires no central infrastructure source or master signal. Control signals can be generated by any node and instantly control the behavior of all nodes in the network. For example, in a large football stadium with 100,000 fans, each fan carries a low-cost node. If programmed, changes in each node's electronic behavior (LED color, flash rate, intensity, sound emission, etc.) can be coordinated by any individual node in the crowd, or by an administrator node sitting in the crowd. The same crowd can leave the stadium, and the synchronized, coordinated behavior will continue. There is no need for a high-energy, centrally located infrared or radio signal within the line of sight of all nodes.

[0055] Group behavior and individual behavior

[0056] The flashing dynamics can be designed to change as two or more bicycles, motorcycles, vehicles, pedestrians, etc. (nodes) are successfully linked. For example, when riding alone, a bicycle's taillight might flash for 100 milliseconds per second. However, when "linked" to another bicycle via radio, infrared, lights, or other signaling methods, the taillight may stop flashing and a "steady burn" mode is initiated where both lights (both bicycles) are continuously illuminated. In a large group, simultaneous flashing may be annoying or not as effective as the steady lighting of the group. The group can select one of a number of "modes" that become the "default" once the group is formed, which may be different from the flashing mode when an individual is riding alone. The lights will have individual and group modes, both of which can be programmable by the operator.

[0057] Although the present invention is described with respect to "moving" pedestrians or vehicles, it should be understood that in some cases, the movement of some or all pedestrians or vehicles may cease. For example, a group of pedestrians or cyclists may stop from time to time and then resume movement. In some cases, the position indicating devices may remain on and may continue to emit their position indicating signals when the pedestrians or vehicles stop. In other cases, the position indicating devices may be turned off when the pedestrians or vehicles stop and then restarted when the pedestrians or vehicles subsequently resume movement. In addition, references herein to moving pedestrians should be interpreted to include not only pedestrians who are walking, jogging, standing or running, but also persons who are performing actions or otherwise moving within an area, such as workers or first responders working in a construction zone or accident scene on or near a road or other thoroughfare.

[0058] It should be understood that although the present invention has been described above with reference to certain examples or embodiments of the present invention, various additions, deletions, changes and modifications may be made to those described examples and embodiments without departing from the intended spirit and scope of the present invention. For example, any element, step, member, component, composition, reactant, part or portion of an embodiment or example may be incorporated into or used together with another embodiment or example, unless otherwise specified or if doing so would make the embodiment or example unsuitable for its intended use. In addition, where the steps of a method or process have been described or listed in a particular order, the order of these steps may be changed, unless otherwise specified or if doing so would make the method or process unsuitable for its intended purpose. In addition, unless otherwise specified, the elements, steps, members, components, compositions, reactants, parts or portions of any invention or example described herein may optionally exist or be used without or substantially without any other element, step, member, component, composition, reactant, part or portion. All reasonable additions, deletions, modifications and changes shall be considered equivalents to the described examples and embodiments and shall be included within the scope of the appended claims.

Claims

1. A system comprising a plurality of wearable signal transmitting devices, comprising: A wearable article includes a wearable garment, footwear, headwear, cap, helmet, hard hat, leg band, arm band, belt, backpack, lanyard, jewelry, earrings, necklace or wristband; and Position indicating devices attached to or integrated into wearable articles; wherein the position indicating device comprises at least one transmitter for transmitting a position indicating signal; Receiver; power supply; and an electronic circuit configured and programmed to; a) receiving, via the receiver, one or more synchronization signals from other position indicating devices located within a synchronization range of the position indicating device; as well as b) in response to receiving one or more synchronization signals from one or more other position indicating devices located within the synchronization range, causing the at least one transmitter to transmit a signal that is synchronized with the signals transmitted by the one or more other position indicating devices located within the synchronization range, wherein the electronic circuit of each position indicating device uses the received synchronization signal to cause its signal transmitter to transmit a position indicating signal which is synchronized with position indicating signals transmitted by other said position indicating devices within said synchronization range; and Each position indicating device starts to transmit a synchronized position indicating signal when it moves into the synchronization range, and stops transmitting a synchronized position indicating signal when it moves out of the synchronization range.

2. The system according to claim 1, wherein the position indication signal is selected from: visible light or infrared light, sound.

3. The system of claim 1 further comprising a Global Positioning System (GPS) receiver.

4. The system of claim 3, wherein the GPS receiver receives a radio clock signal transmitted by a government or standards body, and wherein the electronic circuit is configured to determine its absolute position and relative position based on the radio clock signal.

5. The system of claim 1, further comprising a transmitter for transmitting GPS information.

6. The system of claim 1, wherein the system further comprises a proximity detection device for detecting the approach of an approaching vehicle and causing the transmitted position indication signal to change based on the detected approach of the approaching vehicle.

7. The system of claim 6, wherein the proximity detection device detects the approach of the approaching vehicle by ultrasonic wave, radar, laser reflection or headlight intensity.

8. The system of claim 6, wherein the emitter emits visible light that increases in intensity or changes color in response to the sensed approach of an oncoming vehicle.

9. The system of claim 6, wherein the transmitter emits flashes that become faster or more continuous in response to the sensed approach of an oncoming vehicle.

10. A system according to claim 1, wherein the position indicating device uses one or more synchronization signal transmitters of a type selected from the following to transmit the synchronization signal to other position indicating devices located within the synchronization range: radio frequency transmitters, Bluetooth transmitters, WiFi transmitters, electrical hard wire connections, visible light transmitters, infrared light transmitters, light pulse transmitters, lidar devices, sound transmitters, speakers, impact transmitters, ultrasonic transmitters, radar devices, short-range radar (SRR) devices, medium-range radar (MRR) devices, long-range radar (LRR) devices, mobile devices detectable by motion sensors or motion detectors, and transmitters that emit photon images detectable by cameras.

11. The system of claim 1, wherein the position indicating devices operate as a mesh network when within the synchronization range.

12. The system of claim 1, wherein a position indicating device moving out of the synchronization range stops transmitting the synchronized group position indicating signal and does not transmit any signal.

13. The system of claim 1, wherein the signal transmitter of the position indicating device within the synchronization range emits flashes in a synchronized format selected from the following: Flash sequentially from the first position device to the last position device; Flash sequentially from the last position device to the first position device; Flashing in unison; Flashing continuously and consistently; Flashing of predetermined flashing patterns; Flashing of predetermined color patterns; and Simultaneous flashes from the position indicating devices within the synchronization range.

14. The system of claim 1, wherein each position indicating device comprises: an antenna configured to receive and transmit radio frequency (RF) signals, or a photodetector and transmitter to provide visible light or infrared light modulated communications; Computer hardware including a microcontroller configured to execute instructions stored in a memory; a radio frequency (RF) transceiver or a photodetector configured to send and receive messages from the microcontroller; and power supply; and a memory including a neighbor table, the neighbor table containing timing indicators of neighbor modules, the timing indicators indicating a waiting time before transmitting an alert signal relative to a network coordination clock; Wherein, the computer hardware is configured to share timing and relative position data with at least a neighbor module in its neighbor table, the relative position being at least partially based on a proximity timing indicator, and the timing and relative position data being used to synchronize the simultaneous transmission of the alert signal with at least the neighbor module in its neighbor table.

15. The system of claim 1, wherein the position indicating device emits a position indicating signal selected from the following types: visible light or infrared light, sound.

16. The system of claim 2, wherein the visible light comprises: Continuous visible light, intermittent visible light, light that changes color.

17. The system of claim 2, wherein the sound comprises: Continuous sounds, intermittent sounds, and sounds that change in volume, pitch, type, or character.

18. The system of claim 15, wherein the visible light comprises: Continuous visible light, intermittent visible light, light that changes color.

19. The system of claim 15, wherein the sound comprises: Continuous sounds, intermittent sounds, and sounds that change in volume, pitch, type, or character.

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