The present invention relates to vehicular traffic, particularly on long distance high speed highways, monitoring of the traffic, providing assistance to drivers in the traffic based upon the traffic monitoring and communication with specific vehicles in the traffic. The communications may originate from a vehicle, for example, identifying the vehicle and its location, may be sent to the vehicle to provide driving assistance, or may be sent to and received from the vehicle, for example, as in telephone communications. Further, the system provides for prioritizing travel on a multiple lane highway and for adjusting tolls charged for the use of the highway.
Communication with vehicles on high speed, long distance highways, monitoring traffic on the highways, and monitoring the positions and speeds of specific vehicles on the highways present substantially difficulties. In conventional mobile communications systems, for example, mobile telephones, fixed antennas are installed in the vicinity of highways. Usually, these antennas are elevated, for example, located on the tops of towers or buildings, in order to provide a large area of communication with vehicles. Each fixed antenna at least partially defines a cell and in typical cellular telephone communication, communication shifts from antenna-to-antenna, as a mobile transmitter moves between cells, usually without the notice of the persons, mobile or fixed, who are communicating.
The relatively widely spaced fixed antennas for cellular communication along highways have limitations. For example, each cell has a limited bandwidth from which channels for communication can be assigned. Thus, if too many telephone calls are attempted within a single cell at the same time, all channels may be placed in use so that some potential callers will not be assigned channels and will be unable to establish communication.
If traffic on a highway is to be monitored, and particularly if speeds and positions of individual vehicles are to be determined, simultaneous communication with each of the vehicles on the highway is required. Each vehicle requires a channel for communication. Absent a complicated multiplexing scheme, the bandwidth needed for communication within a typical mobile telephone cell between all of the vehicles traveling on a high speed long distance highway and a fixed antenna readily exceeds the available bandwidth. Therefore, such traffic monitoring is not even theoretically feasible. The bandwidth problem cannot be solved by increasing the available bandwidth because of the number of channels that would be required and limited electromagnetic spectrum availability.
It is an object of this invention to solve the problem imposed by the limited bandwidth available for communication with vehicles, particularly vehicles on a multiple lane high speed long distance highway, so that communication can occur with a large number of vehicles without the necessity of increased bandwidth of the communications.
According to a first aspect, a traffic monitoring system includes lane terminals for detecting passage of a vehicle, a communication antenna, a terminal transceiver for communicating with a passing vehicle through the communication antenna, and a network backbone linking the lane terminals to a data processor for compiling information on passing vehicles sensed.
In a preferred arrangement, a traffic monitoring system for a highway includes first and second adjacent lanes for travel in the same direction, including a first line of the lane terminals located along an outside edge of the first lane, a second line of the lane terminals located between the first and second lanes, and a third line of the lane terminals located along an outside edge of the second lane, each of the first, second, and third lines of the lane terminals including respective network backbones connected the respective first, second, and third lines of the lane terminals.
It is particularly preferable that the system include at least one transverse link interconnecting the first, second, and third network backbones and a principal network backbone connected to the transverse link and providing an interconnection between the first, second, and third lines network backbones and the data processor.
The traffic monitoring system most preferable includes a traffic data base connected to the data processor through the principal network backbone for storing traffic information including passing vehicles detected by the sensor for processing by the data processor.
The traffic monitoring system provides for cellular communication with moving vehicles wherein groups of lane terminals define communication cells for communication with vehicles traveling on the highway and a cell management data base is connected to the data processor for identifying positions of specific vehicles on the highway with respect to the communication cells.
For increased utility, the traffic monitoring system may include a toll server connected to the principal network backbone and receiving information from the lane terminals for determining a toll of a vehicle traveling on the highway based upon the lane traveled by the vehicle.
For greatest utility, the traffic monitoring system includes mobile transceivers mounted on respective vehicles for sending signals to the lane terminals identifying the respective vehicle on which a transceiver is mounted.
Simpler systems may omit communication antennas in the lane terminals or vehicle sensors in the lane terminals.