Abstract:
An electronic traffic alert system for communicating with an emergency vehicle and a centralized traffic control station includes a traffic display having a screen for displaying graphics and configured to hold a plurality of modules. The modules are of substantially uniform shape, such that individual modules are interchangeably connectable to the traffic display, and the plurality of modules are mounted below the screen so that at least one of them extends below the traffic display. The traffic display also includes a central processor in communication with the plurality of modules and the screen, with the central processor configured to display a predetermined graphic on the screen according to input from at least one of the plurality of modules, and an interface for transmitting traffic-related information to the traffic display from and a centralized traffic control station.

Description:
[0001]    This application is a continuation-in-part of co-pending application Ser. No. 14/010,410, filed on 26 Aug. 2013, which claims the priority filing date of provisional application 61/692,804, filed 24 Aug. 2012. 
     
    
     BACKGROUND 
       [0002]    The present invention is directed to electronic signs and signage including hanging signage presenting highly visible visual warnings, messages, or other information to drivers both during the regular course of driving and in emergency situations. 
         [0003]    Powered traffic signals or “stop lights” have existed since the early twentieth century. These signals have remained essentially the same in general concept with a few added refinements added such as turn arrows and symbolic “walk” or “don&#39;t walk” messages. Over the years, ground travel in and around cities has become increasingly congested with growing vehicular traffic including passenger cars, trucks, emergency vehicles, busses, trains and the like all moving through densely-populated areas. 
         [0004]    While non-passenger vehicles such as police cars, fire trucks and ambulances typically emit visual and audible warnings as they approach intersections, they frequently lack the right-of-way, and warnings emitted from their vehicles are often unseen and/or unheard, leading to collisions and injury. In view of the increased density and speed of vehicular traffic and the current primitive state al signage technology, it is desirable for municipalities to provide significantly improved signaling and signage at intersections for better vehicular flow, safety, and to provide warnings and information among other reasons. 
         [0005]    Known systems in the art for interfacing traffic control with emergency vehicles are known. U.S. Pat. No. 5,539,398 to Bystrak et al. discloses an enhanced group addressing system including an apparatus and method for addressing a spaced-apart detectors or control units in a multiple zone detection system. This system, which shortens the time needed for a centrally located control element to communicate with the detectors, is used for existing traffic control systems. 
         [0006]    U.S. Pat. No. 5,172,113 to Hamer discloses a system and method for transmitting data in an optical traffic preemption system. Using this system an ambulance or other emergency vehicle may optically transmit data from an optical emitter to a detector mounted along a traffic route via a stream of light pulses. The light pulses cause a traffic signal to change allowing the approaching emergency vehicle to pass. This system lacks any communication with a central traffic command. 
         [0007]    U.S. Pat. No. 7,113,108 to Bachelder, et al. discloses an emergency vehicle control system traffic loop preemption system. The system uses existing inductive traffic loops that are either “car-active” or “car-passive.” In the “car-active” system, a passive element having position information transmits an ID tag and the position information to a transceiver in the vehicle when an emergency vehicle is detected by the existing inductive traffic loop. In the “car-passive” system, a transceiver at the intersection is activated to send an excitation signal to a transponder on the emergency vehicle, which responds with the emergency vehicle ID. This system interfaces with a central traffic control, but lacks any method of redundantly checking to make sure signal changes occur. 
         [0008]    U.S. Pat. No. 4,704,610 to Davidson et al. discloses an emergency vehicle warning and traffic control system. This system provides early warning of the approach of an emergency vehicle and provides a display to indicate the direction from which the emergency vehicle is approaching, and preemption of traffic signals. A transmitter mounted on an emergency vehicle transmits a signal whenever it is on an emergency call, which is received by infrared receivers positioned at an intersection. This system relies on infra-red transmission of data, and cannot easily integrate with existing traffic central control computer systems. 
         [0009]    Since known systems are inefficient and ineffective in providing information to drivers for collision avoidance or other purposes, the present invention as described herein takes major steps forward to accomplishing these objectives. One important goal of the present invention is to provide a more effective traffic signal preemption system. Currently in the market, devices exist to preempt the normal operation of a traffic signal, such as a strobe light system. While this is useful in emergencies, drivers are often unaware of where the emergency vehicles are as they approach an intersection. By providing programmed LED text and graphical movement, the present invention aims to solve problems in the prior art and reduce emergency response time. Another goal of the present invention is to provide a signal control and data transmission system capable of easy integration into existing systems known in the art. 
       SUMMARY 
       [0010]    An electronic traffic alert system for communicating with an emergency vehicle and a centralized traffic control station includes one or more traffic displays, each comprising a screen for displaying graphics. Each traffic display is configured to hold a plurality of modules. Each of the modules has a substantially uniform shape, such that individual modules are interchangeably connectable to the traffic display according to preference, and the plurality of modules are mounted below the screen such that at least one of the plurality of modules extends below the traffic display. 
         [0011]    Each traffic display also includes a central processor in communication with both the plurality of modules and the screen. The central processor is configured to display a predetermined graphic on the screen according to input from at least one of the plurality of modules. Each traffic display also includes an interface to transmit traffic-related information between the traffic display and a centralized traffic control station, thereby allowing control of the traffic display by the centralized traffic control station. 
         [0012]    A connector strip is located inside each of the traffic displays for removably connecting each of the plurality of modules for ease of service and replacement, the connector strip providing power and information transmission. Preferably multiple traffic displays are located at a single intersection and are wirelessly connected for coordinating messages displayed on the screen of each of the multiple traffic displays. 
         [0013]    In one embodiment, one of the plurality of modules includes an infrared vehicle detector for detecting approaching emergency vehicles and displaying a warning for drivers to pull over. In another embodiment, one of the plurality of modules includes a light sensor and the central processor is configured to automatically change a brightness level of the screen under changing ambient light conditions. In another embodiment, one of the plurality of modules comprises a distance detector for detecting objects persisting under the traffic display. In another embodiment, one of the plurality of modules comprises a parking module in communication with a parking server through a cellular network, the parking module configured to receive available parking space information for display on the screen. 
         [0014]    The central processor may be in communication with a pedestrian crossing monitor that provides the status of pedestrian crossing signals at an intersection where the traffic display is installed. In such a configuration one of the plurality of modules comprises a pedestrian module for displaying on the screen pedestrian crossing signal information corresponding to the status. In various alternative embodiments, the plurality of modules may include features selected from the group consisting of loudspeaker, camera, thermometer, air quality sensor, and back-up battery pack. 
         [0015]    In one preferred embodiment, one of the plurality of modules is capable of receiving emergency-related information from a moving vehicle and thereafter causing the traffic display to indicate the direction of the vehicle to drivers travelling in a perpendicular direction. Additionally, one of the plurality of modules is configured to receive GPS proximity information from a cell phone, wherein the central processor displays an alert on the screen corresponding to the cell phone. Regardless of the modules installed, the traffic display is preferably capable of receiving emergency-related information from the centralized traffic control station and thereafter displaying an alert to drivers regarding lane direction changes. 
         [0016]    The traffic display preferably comprises a protective cowl at least partially around the screen to protect the screen from the elements. The traffic display may also comprise a bumper in front of the screen to protect against impact. In one anticipated installation, the traffic display is mounted proximal a street sign, the traffic display further comprising a light for illuminating the street sign. Each traffic display may also be configured for installation adjacent a second traffic display for creating an enlarged screen. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0017]      FIG. 1  illustrates a perspective view of a first embodiment traffic alert sign affixed to a conventional light/signal pole; 
           [0018]      FIG. 2  illustrates a side view of the traffic alert sign illuminating a street sign; 
           [0019]      FIG. 3  illustrates a bottom perspective view of the traffic alert sign showing interchangeable sensor modules adapted for insertion therein; 
           [0020]      FIG. 4  illustrates a perspective view of the traffic display with an LED screen panel open to access its sensor modules and internal components; 
           [0021]      FIG. 5  illustrates a second embodiment traffic alert sign incorporating a preexisting display screen, with a sensor module being installed therein; 
           [0022]      FIG. 6  illustrates the second embodiment traffic alert sign affixed to a conventional light/signal pole; 
           [0023]      FIG. 7  illustrates a perspective view of an infrared receiver module; 
           [0024]      FIG. 8  illustrates an exploded view of the infrared receiver module; 
           [0025]      FIG. 9  illustrates an intersection with the infrared receiver module in operation detecting an emergency vehicle and the screen displaying a ‘pull over’ signal; 
           [0026]      FIG. 10  illustrates a perspective view of a camera module; 
           [0027]      FIG. 11  illustrates an exploded view of the camera module; 
           [0028]      FIG. 12  illustrates an intersection with the camera module in operation and the screen displaying a government issued abducted child alert; 
           [0029]      FIG. 13  illustrates a perspective view of a thermometer module; 
           [0030]      FIG. 14  illustrates an exploded view of the thermometer module; 
           [0031]      FIG. 15  illustrates an intersection with the thermometer module in operation and the screen displaying an iced road warning; 
           [0032]      FIG. 16  illustrates a perspective view of a range sensor module; 
           [0033]      FIG. 17  illustrates an exploded view of the range sensor module; 
           [0034]      FIG. 18  illustrates an intersection with the range sensor module in operation and the screen displaying a ‘do not enter’ signal; 
           [0035]      FIG. 19  illustrates a perspective view of an air quality sensor module; 
           [0036]      FIG. 20  illustrates an exploded view of the air quality sensor module; 
           [0037]      FIG. 21  illustrates an intersection with the air quality sensor module in operation and the screen displaying an air quality warning message; 
           [0038]      FIG. 22  illustrates a perspective view of a lidar sensor module; 
           [0039]      FIG. 23  illustrates an exploded view of the lidar sensor module; 
           [0040]      FIG. 24  illustrates an intersection with the lidar sensor module in operation and the screen displaying a ‘Do Not Block’ warning message; 
           [0041]      FIG. 25  illustrates a perspective view of a light sensor module; 
           [0042]      FIG. 26  illustrates an exploded view of the light sensor module; 
           [0043]      FIG. 27  illustrates an intersection with the light sensor module in operation and the screen displaying a ‘Turn on Headlights’ warning message; 
           [0044]      FIG. 28  illustrates an intersection with a bicyclist&#39;s cell phone triggering the traffic display to show a ‘bicyclist’ warning message to nearby vehicles; 
           [0045]      FIG. 29  illustrates an intersection with the traffic display showing an emergency vehicle&#39;s direction of travel perpendicular to oncoming traffic; 
           [0046]      FIG. 30  illustrates the interface between the traffic display and a central traffic processing computer, identifying the route of an emergency vehicle; 
           [0047]      FIG. 31  illustrates a series of intersections with traffic displays showing available parking spaces between each intersection; 
           [0048]      FIG. 32  illustrates a third embodiment traffic display arranged vertically for attachment to a street light and displaying parking space availability; 
           [0049]      FIG. 33  illustrates a fourth embodiment traffic display based on the second embodiment, wherein a second pre-existing display screen is installed alongside the first; 
           [0050]      FIG. 34  illustrates a block diagram of an exemplary traffic alert sign installation; 
           [0051]      FIG. 35  illustrates an electrical diagram of the modules and a connector strip; 
           [0052]      FIG. 36  illustrates an electrical diagram of the infrared sensor module; 
           [0053]      FIG. 37  illustrates the infrared sensor interacting with an emergency vehicle; 
           [0054]      FIG. 38  illustrates an electrical diagram of the light sensor module; 
           [0055]      FIG. 39  illustrates an electrical diagram of the lidar sensor module; 
           [0056]      FIG. 40  illustrates an electrical diagram of the power supply; 
           [0057]      FIG. 41  illustrates an electrical diagram of the parking module 
           [0058]      FIG. 42  illustrates an electrical diagram of a pedestrian indicator monitor; and 
           [0059]      FIG. 43  illustrates an electrical diagram of a pedestrian module. 
       
    
    
     DESCRIPTION 
       [0060]    Referring to  FIGS. 1 and 2 , the electronic traffic alert system includes a first embodiment traffic display  10 . The traffic display  10  has a large screen  12  adapted for displaying a variety of signals, warnings and other traffic related information discussed below. In the illustrated embodiment for example, a display matching a street sign  14  associated with the traffic display  10  is displayed. Like the street sign  14 , the traffic display  10  is affixed to a lamp post  16 . In the illustrated embodiment, a specialized mounting bracket  18  is used independent of the street sign mount  20 , for independently affixing the traffic display  10  to the lamp post  16  and allowing it to swing on the mounting bracket  18 . Preferably the traffic display  10  is connected to the mounting bracket  18  in a hinged manner, allowing it to swing relative to the mounting bracket  18 . The screen  12  is protected by a housing  22 , including a cowl  24  for providing shade. A bumper  26  is provided in front of the screen  12  to protect it as well as a series of sensor modules  28  mounted below the screen  12 . The sensor modules  28  provide sensing and data reporting capabilities regarding traffic conditions. Referring specifically to  FIG. 2 , the traffic display  10  is adapted to illuminate the street sign  14 . 
         [0061]    Referring to  FIG. 3 , the traffic display  10  is shown, including the screen  12 , housing  22 , cowl  24  and bumper  26 . Additionally, a series of sensor modules  28  are shown. In the illustrated embodiment, these sensor modules  28  include a loudspeaker module  30 , an infrared sensing module  32 , a camera module  34 , a battery pack module  36 , a thermometer module  38 , a range sending module  40 , an air quality (for example ozone (O3) or carbon monoxide (CO)) sensing module  42  and a blank module  44 . Each of the sensor modules  28  will be discussed individually. In  FIGS. 7-21 . 
         [0062]    Referring to  FIG. 4 , the traffic display  10  is shown opened, to reveal the back side of the screen  12 , and the interior of the housing  22 . A sensor module  28  has been removed from the traffic display  10  to show that all sensor modules  28  have the same outer dimensions, thus allowing users to customize the traffic display  10  with individually selected sensor modules  28 . In this embodiment the sensor modules  28  are installed and removed by opening the screen  12  to access the inside of the housing  22 . As shown in this view, the screen  12  may be made of a series of individual replaceable LED panels  46  arranged adjacent each other and programmed to function as a single screen. Also shown in this view, information generated by the sensor modules  28  is preferably collected at a central processor  48  mounted in the housing  22 . Also mounted to the housing  22  are cooling fans  50  to prevent overheating and moisture collecting in the housing  22 . 
         [0063]    In one embodiment, the central processor  48  may be a CPU, including a mini pc-type CPU having an operating system with graphics capability, memory storage, and on-board RAM memory, including features for wired (e.g., USB, HDMI, 3.5 mm Headphone, and other connectors) and wireless (Bluetooth, WiFi, etc.) data transmission capabilities. To regulate and provide power to the central processor  48 , sensor modules  28 , cooling fans  50 , and to illuminate the street sign  14 , a power supply  52  is also mounted inside the housing  22 . The power supply  48  may receive power from a municipal source powering the lamp post  16 . Additionally, or in lieu of external power, the power supply  48  may receive power from a series of solar cells  54  installed on the top of the traffic display  10 . 
         [0064]    Referring to  FIGS. 5 and 6 , a second embodiment traffic display  100  is shown. The second embodiment traffic display  100  is shown. This embodiment incorporates a pre-existing screen  112  avoiding the need for the first embodiment housing  22 , and requiring only a cowl  124  for shading. The like the first embodiment traffic display  10  the second embodiment traffic display  100  includes a bumper  126  for protection. The second embodiment traffic housing  100  accepts the same sensor modules  28  (such as the blank module  44  shown being installed) as the first embodiment traffic housing  100 , but since the pre-existing screen  112  doesn&#39;t open, the sensor modules  28  are accessed through hinged panels  156  that individually retain the sensor modules  28  under the pre-existing screen  112 . The inside of the second embodiment traffic display  100  is accessed through a rear access panel  158  for maintenance and repair. The rear access panel  158  may be lockable and vented according to preference. The second embodiment traffic display  100  preferably attaches to the same mounting brackets  18  as the first embodiment traffic display  10 , allowing it to be used in the same manner, suspended in a swinging arrangement from the lamp post  16 . 
         [0065]    Referring to  FIGS. 7-21  individual sensor modules  28  and their uses are shown and described. The loudspeaker module  30 , its functions being widely known, requires no individual illustration or discussion. Like all sensor modules  28 , the loudspeaker module  30  can be interchangeably inserted into the first embodiment housing  22  or second embodiment housing  124 . Similarly, the battery pack module  36  and blank module  44 , their features and installation having been described, do not required individual discussion. Since all modules  28  are preferably the same shape, the battery pack module  36  and blank module  44  are installed in the same manner as the other modules  28 . 
         [0066]    Referring to  FIGS. 7 and 8 , the infrared module  32 , like all sensor modules  28 , (including the loudspeaker module  30  and blank module  44 ) includes a top shell  56  and a bottom shell  58 . The top shell  56  includes a connector  60  for communicating with the central processor  48  ( FIG. 4 ). The bottom shell  58  includes a protruding portion  62  designed to extend below the traffic display  10 , thereby clearing the housing  22  and the bumper  26 . An infrared sensor  64  is mounted in the bottom shell  58  and is aimed at oncoming traffic. 
         [0067]      FIG. 9  shows the infrared sensor module  32  is shown in operation installed at an intersection  66 . The infrared sensor  64  is aimed at an oncoming emergency vehicle  68  such as an ambulance as illustrated. A corresponding emitter (not shown) on the emergency vehicle  68  emits an infrared signal (not shown) which is detected by the infrared sensor module  32 . The infrared sensor module  32  communicates with the central processor  48  ( FIG. 4 ), which causes a traffic light  70  the emergency vehicle  68  is approaching to preemptively turn green. This process is similar to conventional infrared emergency vehicle detectors in the art. The process is improved upon herein in that the processor  48  displays a ‘pull over’ signal  72 , such as animated arrows as shown, alerting drivers in front of the emergency vehicle  68  of its presence and reminding them to pull over out of the way. 
         [0068]    Referring to  FIGS. 10 and 11 , the camera module  34  is shown. The camera module  34  includes a multidirectional camera  74  in a camera housing  76  for protection. The camera is preferably steerable upon instructions from the central processor  48  ( FIG. 4 ) and optionally by remote control from another control source. The camera  74  preferably has infrared lighting  78  and infrared sensing capability for viewing in darkness. In one preferred embodiment, license plate and other similar recognition software may perform analysis on images or video captured by the camera  74  to relay information to the police or other authorities. 
         [0069]    Referring to  FIG. 12 , the camera module  34  is shown in operation installed at an intersection  66 . In the exemplary installation, a state issued alert  80 , such as an “amber” (i.e., abducted child) alert causes the traffic display  10  to activate the camera  74 , which may be aimed in various directions, including directions of a predetermined number and position to detect an automobile having a predetermined license plate number (not shown). In connection with activating the camera  74 , the central processor  48  causes the screen  12  to display the state issued alert  80 , thereby alerting other drivers. 
         [0070]    Referring to  FIGS. 13 and 14 , the thermometer module  38  is shown. The thermometer module  38  includes a thermometer  82  for sensing the ambient temperature. Preferably the thermometer  38  is an electronic, lead free, RoHS compliant thermometer, which is sensitive to wind chill and other environmental factors. 
         [0071]    Referring to  FIG. 15 , the thermometer module  34  is shown in operation installed at an intersection  66 . In the exemplary installation, an iced road hazard  86 , such as ice formed in the intersection  66  occurs from freezing temperatures, and the traffic display  10  receiving temperature information from the thermometer  82  causes the screen  12  to display an iced road hazard warning  88 . Since roads function as a heat sink and do not immediately ice over in freezing weather, the central processor  48  may be programmed such that the screen  12  displays the iced road hazard warning  88  after a predetermined time. Additionally, the central processor  48  may be coordinated with the traffic light  70 , causing the traffic light  70  to flash red to cause vehicles  90  to stop before reaching the iced road hazard  86  in the intersection  66 . 
         [0072]    Referring to  FIGS. 16 and 17 , the range sensor module  40  is shown. The range sensor module  40  includes a range sensor  92  that detects the distance between the range sensor  92  and an object. The range sensor  92  is mounted to point downward from the range sensor module  40 , and is preferably a weather resistant ultrasonic sensor, which may be in a PVC housing and with water intrusion resistance common to electrical fittings. The range sensor preferably includes automatic calibration, waveform signature analysis and noise rejection algorithms, to isolate its readings from electrical and acoustic interference. In one embodiment, the sensor is ultrasonic using pulsed signals to detect when a car is present (and detects the corresponding changes in the pulsed signals). Additionally, the system may use an image recognition camera to look at the cars below to detect when cars are in the intersection. 
         [0073]    Referring to  FIG. 18 , the range sensor module  40  is shown in operation installed at an intersection  66 . In the exemplary installation, a vehicle  90  is caught in traffic, and cannot proceed out of the intersection  66 . The vehicle is thus under the traffic display  10  (and range sensor module  40 ). The range sensor  92  is calibrated for the distance between it and the ground under the traffic display  10 . As vehicles pass under the traffic display  10  the range sensor  92  detects changes in distance (from the distance between the range sensor  92  to the ground, to the shorter distance between the range sensor  92  and an upper surface of a vehicle  90 ). 
         [0074]    Normally, the change in distance occurs quickly as vehicles pass under the traffic display  10 . When traffic backs up, a vehicle  90  may remain under the range sensor  92  for a longer period of time. Preferably, the central processor  48  is programmed such that when the range sensor  92  detects a shorter distance that doesn&#39;t alter for a predetermined time, it causes the screen to display a ‘do not enter’ signal  94  cautioning drivers not to enter the intersection. Optionally, the ‘do not enter’ signal  94  may also provide a countdown alerting other vehicles of the number of seconds until the traffic light  70  will turn red. Providing the countdown feature allows vehicles seeing traffic moving on in the distance to ignore the ‘do not enter’ signal since they will be able to cross through the intersection before the traffic light  70  turns red. 
         [0075]    Referring to  FIGS. 19 and 20 , the air quality sensor module  42  is shown. The air quality sensor module  42  includes an air quality sensor  96  that preferably includes an electro-chemical sensor and heater useful for detecting a variety of harmful chemicals, including the aforementioned ozone (O3) and carbon monoxide (CO), which are typical components of ‘smog’ or similar vehicle-caused air pollution. In order to provide gradual gas analysis, the air quality sensor  96  may be recessed in the protruding portion  62 , with a gas port  98  installed thereon. 
         [0076]    Referring to  FIG. 21 , the air quality sensor module  42  is shown in operation installed at an intersection  66 . In the exemplary installation, the air quality sensor  42  continuously monitors the air passing by the traffic signal  10 . If a predetermined chemical is detected above a predetermine threshold amount, the central processor  48  causes the screen to display an air quality warning message  100 , such as an air quality index (AQI) number. Occupants of a vehicle  90  encountering the air quality warning message  100  can take precautions before engaging in strenuous outdoor activities. 
         [0077]    Referring to  FIGS. 22 and 23 , a LIDAR sensor module  102  is shown. The LIDAR sensor module  102  functions similar to the range sensor  92  ( FIG. 16 ) and is an alternative technology for identifying the presence of vehicles  90  ( FIG. 24 ) blocking lanes of traffic on the far side of an intersection  66 , thus disposed under the traffic display  10 . The LIDAR sensor module  102  has the same top shell  56  and bottom shell  58  as the other modules, thus maintaining the interchangeable nature of the modules, and includes a preferably clear LIDAR sensor housing  104  and a LIDAR sensor  106 , which uses laser light to measure distance, and communicates distance changes to the central processor  48 . 
         [0078]      FIG. 24  illustrates an intersection with the LIDAR sensor module  102  in operation and the screen  12  displaying a ‘Do Not Block Intersection’ warning  108  on the traffic display  10 . When a vehicle  90  comes to rest under the LIDAR sensor module  102 , the central processor  48  detects the reduced distance between the traffic display  10  and the vehicle  90 , and causes the ‘Do Not Block Intersection’ warning  108  to appear on its traffic display  10 . Preferably, a corresponding ‘no left turn’ icon  110  appears alongside the ‘Do Not Block Intersection’ message  108 , and both appear on a traffic display  10  corresponding to vehicles  90  that would otherwise block the intersection  66  by making a left turn from a perpendicular direction. Once a vehicle  90  triggering the ‘Do Not Block Intersection’ message  108  and no left turn icon  110  moves out from under the traffic display  10 , the central processor  48  detects the change and stops displaying those warnings. 
         [0079]    Preferably, the central processor  48  is programmed to detect LIDAR changes of a particular distance range to avoid triggering warnings when non-vehicular objects pass under the traffic display  10 . Also, the central processor  48  is preferably programmed to detect LIDAR changes of a particular time interval. In this manner, false alarm warnings when debris (not shown) comes to rest under the LIDAR sensor module  102 , and during the normal passage of vehicles  90  under the LIDAR sensor module  102  are avoided. 
         [0080]    Referring to  FIGS. 25 and 26 , a light sensor module  112  is shown. The light sensor module  112  is used to detect ambient light (i.e., sunlight) in the environment of the traffic display  10 , and prompt the central processor  48  to display a ‘Turn on Headlights’ warning  118 . The light sensor module  112  has the same top shell  56  and bottom shell  58  as the other modules, thus maintaining the interchangeable nature of the modules, and includes a preferably clear light sensor housing  114  and a light sensor  116 , which detects ambient light to measure distance, and communicate changes in distance to the central processor  48 . When the central processor  48  detects a change in 
         [0081]      FIG. 27  illustrates an intersection with the light sensor module  112  in operation and the screen  12  displaying a ‘Turn on Headlights’ warning  118  on the traffic display  10 . When the ambient light (e.g., sunlight or other environmental illumination) falls below a predetermined level, the central processor  48  detects the low light level from the light sensor  116  and causes the traffic display the ‘Turn on Headlights’ warning  118 . Preferably central processor  48  is programmed to detect the speed of light level changes, so that a low light level for a prolonged period of time is required, thus avoiding the ‘Turn on Headlights’ warning  118  being improperly activated from darkness caused by a passing object, or deactivated by a passing light source. Additionally the central processor  48  is preferably programmed such that after a predetermined period of time in darkness the ‘Turn on Headlights’ warning  118  is deactivated when not needed in late hours due to low visibility. 
         [0082]    In some embodiments, the ‘Turn on Headlights’ warning  118  may be hierarchically integrated with other warnings, such that it can be interrupted if needed, such as by the ‘Do Not Block Intersection’ warning  108  when traffic backs up to an intersection. Additionally, the ‘Turn on Headlights’ warning  118  may be integrated with information from the camera module  34  to detect when vehicles  90  are passing the traffic display  10  in near darkness without lights, thus enabling a specific ‘Turn on Headlights’ warning  118  to be directed at a specific vehicle. 
         [0083]    Referring to  FIG. 28 , the central processor  48  of the traffic display  10  may include programming allowing it to interface with a cell phone  120  and generate an alert based on the proximity of the cell phone  120  to an intersection. One exemplary embodiment is illustrated wherein a bicyclist  122  is approaching the traffic display  10  with a cell phone  120  on which a dedicated traffic display  10  interface application running. Using cell signal or other wireless communication, the cell phone  120  communicates the bicyclist&#39;s  122  location (directly or indirectly) to the central processor  48 , which then causes the screen  12  to display a ‘Bicyclist’ warning message  124 . Although the traffic light  70  is green, giving the bicyclist  122  the right of way, by providing the ‘Bicyclist’ warning message  124 , many collisions between the bicyclist  122  and vehicles  90  can be avoided as the bicyclist  122  enters the intersection  66 . 
         [0084]      FIGS. 29-30  illustrate the ability of the traffic display  10  to triangulate the position of emergency vehicles  68  and alert vehicles  90  in cross traffic of an approaching emergency vehicle  68 . As discussed, the infrared sensor module  32  operates similar to existing infrared sensors that engage a traffic light  70 , turning it green or lengthening an already green traffic light  70 . In the embodiments disclosed in  FIGS. 7-9 , the central processor  48  receives infrared signal from the infrared module, and communicates information regarding the signal to one or more central traffic control computers  126 . 
         [0085]    The central traffic control computers  126  record the location of each intersection  66  approached by the emergency vehicle  68 , including the direction from which the emergency vehicle  68  is travelling. By establishing the position and direction of travel of the emergency vehicle  68 , the central traffic control computers  126  can then engage central processors  48  on other traffic displays  10  in the intersection  66  to provide an ‘emergency vehicle crossing’ warning  128 . By providing such a warning, vehicles  90  traveling perpendicular to the emergency vehicle&#39;s  68  line of travel will be advised of its approach. 
         [0086]    Such a warning is important particularly when the infrared sensor module  32  picks up infrared signal from an approaching emergency vehicle  68  and causes a traffic light  70  to turn red prematurely. Without such a warning, vehicles  90  may be encouraged to speed up to try and make it through the intersection before the light turns red. Preferably, the traffic control computers  126  create a travel record the entire route of an emergency vehicle  68 , and have the ability to select among a variety of appropriate ‘emergency vehicle crossing’ warnings  128 . In addition to the ‘emergency vehicle crossing’ warning  128  appearing on the central traffic control computers  126 , a travel record  130  is also displayed, reflecting the extended route of an emergency vehicle  68 . 
         [0087]    Referring to  FIG. 31  by interfacing with a series of smart parking meters  132 , several traffic displays  10  can be used in high-commerce areas to coordinate the parking of vehicles  90 . When performing this function, the central processor  48  of a traffic display  10  collects data from all parking spaces  134  along a city block  136 ; preferably each block  136  is behind the traffic display  10  when viewed from an oncoming vehicle  90 . The central processor  48  of the traffic display  10  receives information from each smart parking meter  132 , and indicates the number of parking spaces  134  along each city block  136 . Examples include a ‘5 parking spaces’ message  138  or a ‘3 parking spaces’ message  140 . In areas where there are no parking spaces, particularly at times when most drivers are looking for parking, such as during a sporting or holiday even, the screen may display a detour message  142 . Optionally, for safety, identifying free parking spaces  134  only occurs when the traffic light  70  is red. 
         [0088]    Referring to  FIG. 32 , a third alternative embodiment display  300  is shown. The traffic display  300  is oriented for installation on a municipal pole  310  with or without a traffic light (not shown), using mounting bands  312  which are preferably steel or a similar resilient material. The traffic display  300  includes a specially designed hood  314  for vertical orientation and shading the screen  316  from sunlight. The traffic display is preferably installed on a corner (not shown), such that it can indicate available parking spaces along two perpendicular streets converging on the corner. 
         [0089]    Referring to  FIG. 33  a fourth alternative embodiment display  400  is shown in a partially exploded view. This embodiment takes advantage of the modularity of pre-existing screens  412  allowing multiple pre-existing screens  412  to be individually fitted with cowls  424  and bumpers  426  to create an elongated traffic display  400 . This view also shows the modules  428  which are inserted into the hinged panels  456  of a module dock  460 . Module ports  462  on the pre-existing screen  412  allow access to the modules  428  from within the pre-existing screen  412 . 
         [0090]    Referring to  FIG. 34 , a block diagram of the traffic alert sign  10  is shown, comprising an off-the-shelf LED panel  46  and a hub  144  which supports many different optional modules  28  to improve traffic flow and public safety. A connector strip  146  may be provided for providing power and information transmission from the modules  28  to the central processor  48  and power supply  52 . Although the hub  144  accepts any of the modules  28 , the modules  28  of the illustrated embodiment include an infrared module  32  for detecting oncoming emergency vehicles, such as fire trucks and ambulances and warns other vehicles to move to the right and stop. Preferably the infrared module  32  supports supports the GTT® OPTICOM® infrared sensor (not shown). 
         [0091]    Other modules include the lidar sensor module  102  for sensing gridlock and displaying a “Do Not Block Intersection” message  108 , the camera module  34  that transmits real-time video back to a central traffic control computer  126 , the light sensor module  112  that senses street brightness and issues a “Turn On Headlights” message reminding drivers to turn on their headlights at dusk and also adjusts the LED panel  46  brightness, the parking, a parking module  148  that receives parking information and informs drivers of available parking spaces in the vicinity. This module can be made to support the IPS GROUP® API (application programming interface). The parking module  146  may be in contact with a parking management server  150  which coordinates parking information for a predetermined area such as a neighborhood or municipality. Additionally, the parking module  146  and parking management server  150  may be connected using a network connection  152 , including the Internet. Other modules  28  maybe included according to desired functionality, making the traffic alert sign  10  fully customizable. 
         [0092]    Referring to  FIG. 35 , an electrical diagram of the embodiment shown in  FIG. 34  is shown, with the connector strip  146  connected to the infrared module  32 , lidar sensor module  102 , camera module  34 , central processor  48 , power supply  52 , light sensor module  112  and parking module  148 . Preferably the connector strip  145  includes magnetic connections for ease of replacement, particularly when performed in the field, and all sensor modules  28 , including those illustrated, preferably connect to the connector strip  146  electrically via cables. The connector strip includes an AC terminal block  154  and several AC power outlets including a 2×10 IDC connector  156  and several 1×4 connectors  158 . 
         [0093]    The connector strip  146  handles routing AC power, 5 Vdc power, 24 Vdc power, and I/O pins. It preferably accepts 120/240 Vac as input at terminal block  2 , goes through a fuse and MOV surge protector (not shown), and routes it to the 1×4 connectors  158  to provide power to the sensor modules  28  (including those illustrated). All 5V pins of the connector strip  146  are connected together to provide 5V to the central processor  48  and the sensor modules  28 . The 5V pin associated with the power supply module  52  receives power from the power supply module  52 . Preferably all G pins of the connector strip  146  are connected together to provide a common ground to all modules. Two different I/O pins of the 2×10 IDC connector  156  are routed to the 1×4 IDC connectors, and all the I/O pins of those modules are connected through a cable to the central processor module  48 . Firmware in the central processor module  48  keeps track of the pin assignments. 
         [0094]    Referring to  FIG. 36 , an electrical diagram of the infrared module  32  is shown. The infrared module  32  is connected to the connector Strip  146 . Through the connector strip  146 , it gets 24 Vdc from the power supply  52  and outputs a signal to the central processor  48 . It receives IR signal from an IR emitters mounted on an emergency vehicle, such as a fire, ambulance, or police vehicle. Upon activation, it sends a signal to the central processor  48 , and with the preconfigured direction in which the infrared sensor  64  is pointed, the central processor  48  sends a message to the traffic display  10  to warn motorists of an approaching emergency vehicle. In one preferred embodiment, the message can be an animated right-moving chevron display, among other displays. Additionally, the infrared central processor  48  relays the message to other traffic displays  10  at an intersection. Referring to  FIG. 38 , the infrared detector is connected to the central processor  48  and the power supply  52 . Since the infrared detector housed in module underneath the traffic sign  10 , it is installed upside down. 
         [0095]    Referring to  FIG. 38 , an electrical diagram of the light sensor module  112  is shown, capable of detecting street brightness and warning motorists to turn on their headlights. It is composed of a light sensor  116 , a circuit, and a 4-pin connector, and is connected to the connector strip  146 . Through the connector strip  146 , the light sensor module receives 5 Vdc from the power supply  52  and transmits an analog signal to the central processor  48 . It works as follows: At dusk, when the sky darkens, the resistance in the light sensor  116  increases causing the voltage at pin  2  to increase. The central processor  48  reads this higher voltage to determine that it is now at dusk and sends a message to the traffic display  10  to display a “Turn on Headlights” warning. 
         [0096]    Referring to  FIG. 39 , an electrical diagram of the lidar sensor module  102  is shown capable of detecting traffic gridlock at an intersection. The lidar sensor module is composed of a lidar (light Detection And Ranging) sensor  106 , a circuit, and a 4-pin connector connected to the connector strip  146 . Through the connector strip  146  the lidar sensor module receives 5 Vdc from the power supply  52  and outputs a signal to the central processor  48 . The lidar sensor module  102  is installed with the lidar sensor  102  pointed downward and controlled by the central processor  48  to sense distances below the lidar sensor module  102 . When a vehicle  90  is directly underneath it, the distance detected is less than when no vehicle  90  is under it. When a vehicle  90  idles below the lidar sensor module  102  it for more than 5 seconds, or another pre-programmed period of time, it interprets the condition as a traffic backup at the intersection, and the central processor  48  software thus causes a “Do Not Block Intersection” warning to appear on the traffic display  10  to avoid a traffic gridlock condition. 
         [0097]    Referring to  FIG. 40 , the power supply  52  provides 5 Vdc and 24 Vdc to the connector strip  146 , which in turn distributes power to the sensor modules  28  (including the lidar sensor module  102 , light sensor module  112 , infrared sensor module  32 , etc.) The power supply  52  is preferably composed of an off-the-shelf power module to provide 5 Vdc and 24 Vdc wired to the proper pins on the 1×4 IDC connector  158  when connected to the connector strip  146 . The traffic display  10  is designed with a connector strip  146  and removable sensor modules  28  such that if a power supply  52  fails, it can be replaced easily in the field. 
         [0098]    Referring to  FIG. 41 , the parking module  148  enables the traffic display  10  to connect to a parking management center to obtain parking information to inform motorists of parking availability. The parking module  148  is connected to the central processor  48  through the connector strip  146  on RX and TX lines The central processor  48  preferably uses the parking module  148  to connect through a commercial cellular network to a parking management center or parking meters in order to display available parking spaces in the vicinity of the traffic display  10 . 
         [0099]    Referring to  FIG. 42 , a pedestrian indication monitor  160  monitors the Walk and Don&#39;t Walk signals used in a typical four pedestrian phase intersection where four crosswalks are controlled by a central traffic control computer  126 . Upon receiving information from the central traffic control computer  126 , the pedestrian indication monitor  160  sends the Walk and Don&#39;t Walk information wirelessly to individual traffic displays  10  using a pedestrian module  162  ( FIG. 43 ). When the traffic displays  10  receive information from the pedestrian indicator monitor  160 , the central processor  48  of each traffic display  10  displays a pedestrian walking image to warn drivers to watch for crossing pedestrians. 
         [0100]    Referring to  FIG. 43 , the pedestrian module enables a traffic display  10  to receive pedestrian indication information wirelessly from the pedestrian indication monitor. This module is connected to the central processor  48  through the connector strip  146  on the RX and TX lines. When the traffic display  10  receives the message programmed for its particular location, it will display the pedestrian walking image to warn motorists of crossing pedestrians. 
         [0101]    While the present invention has been described with regards to particular embodiments, it is recognized that additional variations of the present invention may be devised without departing from the inventive concepts.