Abstract:
Traffic signal data is broadcast, for receipt by vehicles traversing the roadways controlled by the traffic signals. If desired, traffic lights are provided with the capability to broadcast their location, status, changing cycles and timing data continuously. A receiving system in a vehicle is configured to receive the traffic signal data and display, to a user of the vehicle, visual display information and/or audible information informing the user of a speed range which, if followed, optimizes the use of the highway and minimizes the number of starts and stops that must be made.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to traffic control systems and, more particularly, to a “smart” system that broadcasts traffic signal status to vehicle-based receivers. 
   2. Description of the Related Art 
   Automobiles are a part of everyday life in urban and suburban communities. Traffic lights dot the landscape in urban centers and the surrounding communities, and control the flow of traffic on roads, large and small. Drivers must pay attention to traffic signals and failure to heed them results in increased traffic congestion and accidents. 
   While traffic controls are a necessary part of any road and highway system, measures are taken to try to keep the traffic flow on the major arteries moving as much as possible. It is well known, for example, to “time” lights along a stretch of highway so that vehicles progressing along the highway at the legal speed limit will encounter a reduced number of red lights causing them to have to stop. 
   Timing of lights operates adequately as long as people are going the speed limit and the traffic is not impeding their progress. However, it is fairly common for users of highways and roads to exceed the speed limit without considering the timing of the lights; in fact, most drivers may be unaware of the timing of the lights and not realize that obeying the speed limit will smooth their progression along the road. Thus, urged on by the fast pace of everyday life, many will find themselves stopping and starting along the highway, since their high speeds negate the benefit of the timing of the lights. 
   In addition to being dangerous, this type of driving wastes fuel and results in unnecessary wear on brakes and other vehicle components used during the braking and acceleration process. Accordingly, it would be desirable to have a method and system which would prompt drivers to maintain speeds that minimize the amount of acceleration and stopping that they need to do, and encourage compliance with speed limits. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, traffic signal data is broadcast, for receipt by vehicles traversing the roadways controlled by the traffic signals. In a preferred embodiment, traffic lights are provided with the capability to broadcast their location, status, changing cycles and timing data continuously. A receiving system in a vehicle is configured to receive the traffic signal data and display, to a user of the vehicle, visual display information and/or audible information informing the user of a speed range which, if followed, optimizes the use of the highway and minimizes the number of starts and stops that must be made. 
   In a representative embodiment, the present invention comprises a method of disseminating, to a vehicle, traffic signal information regarding a traffic signal, comprising the steps of: broadcasting traffic signal data identifying present and future traffic signal sequences for the traffic signal; receiving the traffic signal data by the vehicle; calculating, based on the received traffic signal data, a speed range to be followed by the vehicle to minimize the amount of stopping, starting, and/or speed changing required while enabling the vehicle to progress past the traffic signal; and displaying the calculated speed range to occupants of the vehicle. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates the general architecture of the present invention; 
       FIG. 2  is a flowchart illustrating the operation of the present invention; 
       FIG. 3  illustrates an example of a display that is displayed in the vehicle; 
       FIG. 4   a  illustrates an example of the overall operation of the present invention; 
       FIG. 4   b  illustrates the display device in a vehicle displaying information; 
       FIG. 5  is a block diagram of a receiver  500  in accordance with the present invention; and 
       FIG. 6  is a block diagram illustrating a traffic light  600  in accordance with the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  illustrates the general architecture of a preferred embodiment of the present invention. As shown in  FIG. 1 , a vehicle  100  approaches a traffic signal  102 . Traffic signal  102  is equipped with a transmitter  104 . Transmitter  104  broadcasts, on a regular basis, traffic signal data identifying its location (e.g., by broadcasting, for example, GPS coordinates associated with its location). In addition, traffic signal  102  transmits traffic signal data identifying present and future traffic signal sequences, e.g., current information regarding the status of the light (red, greed, or yellow), timing data related to its cycle, and any schedule information regarding future cycles (e.g., if at a particular time of day, the timing of the signal cycle changes due to changing traffic conditions, this information is also transmitted). Although the described embodiment illustrates a transmitter associated with each traffic signal, it is understood that data pertaining to multiple traffic signals, e.g., all traffic signals in a particular region or controlling a particular roadway, could be gathered in a central location using standard telemetry-gathering techniques, and then broadcast regionally from a centralized, independent transmission source. In such an alternative embodiment, the traffic signals, being connected via wires to central locations for power and control purposes, could use a wired or a wireless network to forward the traffic signal data to the centralized transmission source, such as a collecting server. The information transmitted may also include directional components associating the data elements with the light orientation, i.e., the cycle data for vehicles approaching the signal in the north-south direction will be identifiably different from the cycle data for vehicles approaching the signal in the east-west direction. Further, the transmitted information may also include data related to right and left turn arrows, blinking lights, or any other light status information pertaining to the transmitting light. 
   Vehicle  100  is equipped with a receiver  106 , illustrated representatively by an antenna on vehicle  100  in  FIG. 1 . The onboard receiver  106  of vehicle  100  captures the broadcast traffic signal data from traffic signals (or independent transmission sources) within its vicinity. A traffic-signal processor is integrated into, or coupled to, receiver  106  and receives the captured traffic signal data and, together with vehicle information (e.g., current vehicle speed, vehicle location, etc.) obtained from an onboard GPS system and/or a vehicle system processor associated with the vehicle, calculates an optimal pace to facilitate traffic flow. For example, by receiving the traffic light transmission data and calculating the distance to the light and the speed limit for the road on which the vehicle is traveling, the driver and/or passengers of vehicle  100  can have displayed to them information identifying the optimal speed range to allow the driver to successfully pass through the upcoming traffic light or lights without having to significantly slow down or stop. If conditions are such that the driver cannot make the light and still maintain a legal speed (maximum or minimum), then the display can go blank, or display an indication advising the user of this fact. 
     FIG. 2  is a flowchart illustrating the operation of the present invention. At step  202 , the monitoring process commences. This would typically coincide with the ignition of the vehicle being turned on, thereby activating the receiving device; however, it could also be turned on by the user “on demand”. 
   At step  204 , the receiver in the vehicle acquires the transmitted signal from the next upcoming traffic light. In actuality, the receiver will acquire transmitted data from any traffic lights within range, including the next upcoming traffic light. To identify which of the data to use for performing the vehicle speed information, etc., at step  206 , the applicable data (i.e., data associated with the next upcoming light) is identified, based upon vehicle GPS information and the location information for the transmitting lights. 
   The vehicle GPS information includes the vehicle location, the vehicle direction-of-travel, the speed of travel, and can even be as fine-grained as which lane on which particular roadway the vehicle is moving. Based upon this information, the processor of the present invention will “filter out” all but the data related to the next upcoming traffic signal. The vehicle GPS information is obtained from a standard vehicle GPS system commonly factory installed, or installed as an after-market item, in vehicles today. Some or all of the information can also be acquired via on-board vehicle processors that are routinely used to, for example, display the vehicle speed to the driver on a dashboard display; the information from the vehicle processor can also be output to the traffic system processor for use in performing the calculations described herein. 
   At step  208 , the appropriate calculations are performed by the traffic system processor. This will include, for example, the amount of time that will pass before the upcoming light will change from red to green (or green to red, etc.) and the speed range that the vehicle should maintain to pass the upcoming light without needing to stop. The traffic signal, preferably, also transmits speed limit information for the road on which the vehicle is traveling. 
   At step  210 , a determination is made as to whether or not the currently monitored signal is still relevant. If the vehicle is still approaching the traffic light, then the information is still relevant and of interest to the passenger or driver of the vehicle. Once the vehicle passes the traffic signal, the information becomes irrelevant and is not of interest anymore; instead, it is preferable that the receiver begin to pick up signals from the next upcoming traffic signal. Since the vehicle GPS data identifies where the vehicle is located relative to the transmitting traffic signals, it is a simple matter to determine the relevancy of any of the transmitting traffic signals to the vehicle at any given moment, i.e., by calculating distances and selecting the shortest one, taking into consideration the direction of travel and the road being traversed. Accordingly, if, at step  210 , it is determined that the currently monitored signal is no longer relevant, then the process proceeds back to step  204  to acquire the transmitted signal from the next upcoming traffic light and the process proceeds as described above. If, on the other hand, it is determined at step  210  that the currently monitored signal is still relevant, then at step  212 , steps are taken to refresh all data, calculations, and displays. This means that the signal continues to be monitored from the traffic light and the appropriate data continues to be identified and used to perform calculations for display in the vehicle. The process then proceeds back to step  210  to again determine if the currently monitored signal is still relevant. 
   Using the process described above, a passenger or driver of a vehicle containing a receiver configured in accordance with the present invention will continually monitor upcoming traffic signals and be given indications as to the most efficient means of proceeding. 
     FIG. 3  illustrates an example of a display that is displayed in the vehicle. As can be seen from  FIG. 3 , on the left side of a display, the speed limit on the road on which the vehicle is traveling is displayed. In the center, information regarding the appropriate speed range required to pass the upcoming light without stopping is identified. On the far right, a “countdown clock” provides the driver or passenger with information regarding the status of the upcoming light and when it is expected to change. This third category of information can be useful, for example, in a situation where a driver is stopped at a traffic light and wishes to get out of the vehicle to check a tire or clear the windshield, etc. Using this third display in  FIG. 3 , the user will know how much time is left before the light will change and thus know if there is sufficient time to leave the vehicle and perform the desired task. It is understood that  FIG. 3  is just a representative example illustrating a possible configuration for a display in accordance with the present invention. Numerous other configurations for displaying any information derivable from the traffic light data and vehicle data will be apparent and are considered to be part of this disclosure. 
     FIG. 4   a  illustrates an example of the overall operation of the present invention. In this example, a vehicle  402  is traveling northbound on Lynn Lane approaching the intersection of Lynn Lane with Dawn Drive, as shown. Beyond Dawn Drive, Lynn Lane intersects Kelly Drive. At each intersection, a traffic light controls the flow of traffic. Specifically, at the intersection of Lynn Lane and Dawn Drive, traffic light  404  controls traffic, and at the intersection of Lynn Lane and Kelly Drive, traffic light  406  controls the flow of traffic. 
   Vehicle  402  is one-quarter mile from the traffic light traveling at 60 miles per hour. The minimum speed along this road is 40 mile per hour and the maximum speed is 65 miles per hour. Drivers approaching traffic light  404  in the northbound lane of Lynn Lane have the option of turning left from left-turn lane  410 , right from right-turn lane  412 , or proceeding through the intersection in lane  414 . Traffic light  404  has a left turn signal, a right turn signal and a regular, red-yellow-green light for controlling traffic proceeding through the intersection. Both traffic lights  404  and  406  are configured in accordance with the present invention to transmit signal data to vehicles within range of their transmitter, e.g., within five miles. The present invention is not limited to this range and it is understood that the transmitters can transmit as far as desired, depending upon the needs of the operator of the traffic control system. 
   Each traffic light has a unique code that it transmits identifying itself, and separately identifies data by the direction of traffic flow that is being controlled. For example, traffic light  404  transmits a first set of data with an identifier indicating it pertains to signals information for northbound traffic; a second set of data with an identifier indicating it pertains to signal information for eastbound traffic; a third set of data with an identifier indicating it pertains to signal information for southbound traffic; and a fourth set of data with an identifier indicating it pertains to signal information for westbound traffic. Any unique identifiers can be used as long as they identify the various signals, directions, and, if desired, lanes to which the data being transmitted applies (e.g., the data identified as being signal information for northbound traffic can be further specified, by use of appropriate identifiers, as being data for the left lane, center lane, or right lane). For identifying the traffic light itself, GPS coordinates or any other method can be used, as long as unique identifiers are transmitted associated with the appropriate data and can be “decoded” by receiving devices in vehicles. 
   As described above, vehicle  402  may be receiving light cycle information from several traffic signals at once, including, in this example, from both lights  404  and  406 . However, since vehicle  402  is equipped with a GPS device, the vehicle location, direction of travel, and speed is known or can be calculated, and this vehicle information, combined with the transmitted information from the lights that has been received by the vehicle&#39;s receiving device, allows the filtering out of all transmitted data except for the data from the nearest light that the vehicle is approaching. Thus, in this example, traveling in the center lane and approaching light  404 , vehicle  402  will receive, at minimum, data pertaining to the standard red-yellow-green light (for the northbound center lane), and potentially the data for northbound left-turn and right-turn signals as well. The display device in vehicle  402  could then, for example, display the information shown in  FIG. 4   b . As can be seen in  FIG. 4   b , vehicle  402  can tell that the red left-turn signal and red center lane signal will change to green in 15 seconds, and the green right-turn signal will change to its next sequence (e.g., a yellow right-turn arrow, a steady green, etc.) in 40 seconds. Further, the user also knows that the left-turn signal will change again in 40 seconds, the center lane light will change again in 40 seconds, and the green right-turn arrow will change again in 65 seconds. Finally, the user is told that by traveling between 35 and 50 miles per hour, in any of the lanes, the driver will “make” the light. In addition, the user is also given the information that they are ¼-mile from the traffic light and currently traveling at 60 miles per hour. It is understood that any desired information can be displayed (e.g., the street names of the intersection being approached) as long as the data required to display the information is available. 
   It is understood that in some situations, drivers utilize pre-programmed routes in connection with GPS devices, such that driving directions are given to the user as they proceed along a road. If the user has pre-programmed such a driving itinerary, and the user has set a plan that would cause him or her to turn left onto Dawn Drive off of Lynn Lane, then if desired, the system could be configured to only display the data for the left-turn lane of Lynn Lane as the driver approaches light  404 . 
   For safety, the system can be configured, if desired, to always provide a “buffer” for the vehicle so that if the driver follows the suggested speeds, they will never be entering the intersection precisely at the time of a light change, thereby reducing the chance that they will impact a driver starting prematurely in the intersecting road. 
   The above-described steps can be implemented using standard well-known programming techniques. The novelty of the above-described embodiment lies not in the specific programming techniques but in the use of the steps described to achieve the described results. Software programming code which embodies the present invention is typically stored in permanent storage of some type, such as permanent storage of a receiving device and/or transmitting device described herein. In a client/server environment, such software programming code may be stored with storage associated with a server. The software programming code may be embodied on any of a variety of known media for use with a data processing system, such as a diskette, or hard drive, or CD-ROM. The code may be distributed on such media, or may be distributed to users from the memory or storage of one computer system over a network of some type to other computer systems for use by users of such other systems. The techniques and methods for embodying software program code on physical media and/or distributing software code via networks are well known and will not be further discussed herein. 
   It will be understood that each element of the illustrations, and combinations of elements in the illustrations, can be implemented by general and/or special purpose hardware-based systems that perform the specified functions or steps, or by combinations of general and/or special-purpose hardware and computer instructions. 
   These program instructions may be provided to a processor to produce a machine, such that the instructions that execute on the processor create means for implementing the functions specified in the illustrations. The computer program instructions may be executed by a processor to cause a series of operational steps to be performed by the processor to produce a computer-implemented process such that the instructions that execute on the processor provide steps for implementing the functions specified in the illustrations. Accordingly, the appended figures support combinations of means for performing the specified functions, combinations of steps for performing the specified functions, and program instruction means for performing the specified functions. 
     FIG. 5  is a block diagram of a receiver  500  in accordance with the present invention. Referring to  FIG. 5 , a traffic signal receiver processor  502  is coupled to a receiver  504 , which is coupled to a receiving antenna  506 . A display  508  and memory  510  are also coupled to traffic signal processor  502 . A vehicle processor  512  and GPS  514  are coupled to receiver  500  as well. 
   Traffic signal receiver processor  502  can comprise any known processing device and in a preferred embodiment comprises a computer processor or other processing means that can be powered by a vehicle power source, traditionally a 12 volt system. Most vehicles contain processors today and it is understood that an existing processing device of a vehicle can be programmed to perform the processing functions of traffic signal receiver processor  502 . 
   Receiver  504  and antenna  506  can comprise any known receiving means that is capable of wirelessly receiving data signals and forwarding the received data signals to a processing device such as traffic signal receiver processor  502 . Display  508  can comprise any known display device, e.g., LED displays, LCD displays, CRT&#39;s and the like. Memory  510  is for storing programming information and received data, as well as any other data that might be used by traffic signal receiver processor  502 . Any known memory device that can perform these functions can be used for memory  510 . 
   Vehicle processor  512  and GPS  514  are shown as separate components with respect to receiver  500 ; however, it is understood that each of these devices can be integrated as part of receiver  500  and still fall within the scope of the present invention. Vehicle processor  512  comprises, for example, any processor that is installed in a vehicle to gather, store, and display data relevant to the operation of the vehicle in which it is installed. For example, vehicle processor can comprise an on-board processing device that gathers data from vehicle systems and calculates and displays vehicle speed, direction of travel, engine temperature, and other standard parameters. 
   GPS  514  comprises a standard GPS system found in vehicles today, which includes sensing hardware and software enabling position information regarding the vehicle in which it is installed to be determined. It may also include processing hardware and software enabling the display, within the vehicle cabin, of a map showing the vehicle and its relationship to landmarks on the map, and allow the plotting of itineraries and the display (both visually and audibly, of travel directions form point to point, all in a well known manner. Both the vehicle processor  512  and GPS  514 , if not integrated into the receiver  500 , must provide access to data output form each device so that it can be used by the traffic signal receiver processor  502 . 
     FIG. 6  is a block diagram illustrating a traffic light  600  in accordance with the present invention. A traffic light and processor  602  comprises any standard traffic signal device having on board or remote control capability. The traffic light and processor  602  must include output means (terminals, wireless outputs, or any other means of outputting data) enabling the various states, cycles, and other operational information to be output to a traffic signal transmitter processor  604 . Traffic signal transmitter processor  604  can comprise any processing device capable of receiving data and configured to store, identify, perform calculations on, or otherwise process the data in accordance with the present invention. A computer or other known processing means will suffice for performance of these functions. 
   GPS  610  is coupled to traffic signal transmitter processor  604  and is configured to supply location data to traffic signal transmitter processor  604  so that the location of the traffic light in which it is installed can be determined and transmitted. Transmitter  606  and transmission antenna  608  are coupled to traffic signal transmitter processor  604  and are configured to receive data from traffic signal transmitter processor  604  and transmit the data in a well known manner. The transmitter  606  must be compatible with receiver  508  of  FIG. 5 , so that the two devices are capable of communicating information from the traffic signal  600  to the receiver  500 . Any known method of transmission, e.g, radio frequency (RF) transmission, will function for the transmit/receive functions of the present invention. 
   While there has been described herein the principles of the invention, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation to the scope of the invention. Accordingly, it is intended by the appended claims, to cover all modifications of the invention which fall within the true spirit and scope of the invention. 
   Although the present invention has been described with respect to a specific preferred embodiment thereof, various changes and modifications may be suggested to one skilled in the art and it is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.