AUTOMATIC TRAFFIC CONTROL SYSTEM

• US 3,828,307 A
• Filed: 06/29/1971
• Issued: 08/06/1974
• Est. Priority Date: 06/29/1971
• Status: Expired due to Term

• Current Assignee: Ernest Timmons Hungerford
• Original Assignee: Ernest Timmons Hungerford
• Inventors: Hungerford, Ernest Timmons
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US05/157,871
• Time in Patent Office: 1,134 Days
• Field of Search: 340/35,37,40,41
• US Class Current: 340/909
• CPC Class Codes: G08G 1/081 Plural intersections under common control
• CPC Class Codes: G08G 1/087 Override of traffic control, e.g. by signal transmitted by an emergency vehicle

Abstract

An automated control system is disclosed that is particularly adapted for use in regulating urban traffic flow. The system includes a central control facility linked with a plurality of remote terminals over a unitary communication channel, which is preferably equivalent to a voice grade, non-compensated telephone line. The central control facility includes a computer coupled through interface equipment with a master transceiver. The master transceiver couples the computer and interface equipment with the communication channel. Each of the remote terminals, which are coupled to the communication channel in parallel, party line fashion, includes a remote transceiver coupled through interface equipment to a traffic control device, such as a signal light. An emergency vehicle locator may also be included in each remote terminal. Vehicle detectors may be coupled to the communication channel through the remote terminals or through separate remote transceivers to provide a measure of traffic flow parameters.

Claims

1. An automated traffic control system comprising:

a central control facility, said central control facility including computer means for processing input information signals and for generating traffic control signals, and computer interface means in said central control facility coupled to said computer for applying said input information signals to said computer means and for transmitting said traffic control signals from said computer means;

signal communication means in said central control facility, said signal communication means coupled to said interface means and including multiplexing means;

a single communication line coupled to said signal communication means for transmitting signals to and from remote points; and

a plurality of remote terminal means coupled to said single communication line in parallel, party-line fashion for receiving said traffic control signals from said computer means and for supplying said input information signals to said computer means over said single communication line.

2. An automated traffic control system as in claim 1, wherein:

said communication line includes a voice grade, non-compensated communication line.

3. An automated traffic control system as in claim 1, wherein:

said computer means comprises a digital computer facility.

4. An automated traffic control system as in claim 1, wherein:

said signal communication means includes master transceiver means coupled to said communication line for transmittIng signals over and receiving signals from said communication line.

5. An automated traffic control system as in claim 4, wherein:

said computer interface means includes input-output storage register means for temporariliy accumulating signals to be fed into said computer means and for temporariliy accumulating signals generated by said computer means.

6. An automated traffic control system as in claim 4, wherein:

said master transceiver means includes a coarse synchronization signal generating means for conditioning said remote terminal means to receive a synchronization signal.

7. An automated traffic control system as in claim 4, wherein:

said master transceiver means includes a fine synchronization signal generating means for preparing said remote terminal means to receive and decode data from said central control facility.

8. An automated traffic control system as in claim 4, wherein:

said master transceiver means includes means for generating a stable carrier reference for enabling said remote terminal means to decode data transmitted from said central control facility.

9. An automated traffic control system as in claim 4, wherein:

said master transceiver means includes means for establishing a data input gate interval for defining a period during which data is transmitted from said central control facility to said remote terminal means.

10. An automated traffic control system as in claim 4, wherein:

said master transceiver means includes means for establishing a data response gate interval for defining a period during which data is transmitted from said remote terminal means to said central control facility.

11. An automated traffic control system as in claim 4, wherein:

said master transceiver means includes said multiplexing means for permitting time shared use of said communication line.

12. An automated traffic control system as in claim 4, wherein:

said remote transceiver means includes means for recognizing only traffic control signals which are directed uniquely to a particular one of said remote transceiver means.

13. An automated traffic control system as in claim 1, wherein:

Said remote terminal means include remote transceiver means coupled to said communication line for transmitting signals over and receiving signals from said communication line.

14. An automated traffic control system as in claim 13, wherein:

said remote terminal means include traffic control means for regulating traffic flow; and

, terminal interface equipment for coupling said traffic control means with said remote transceiver means.

15. An automated traffic control system as in claim 14, wherein:

said central control facility includes a visual display means for displaying the various conditions of said traffic control devices.

16. An automated traffic control system as in claim 14, wherein:

said remote terminal means include local controller means for controlling the operation of said traffic control means according to a self-contained predetermined program.

17. An automated traffic control system as in claim 16 wherein:

said remote terminal means include emergency vehicle detector means for sensing the presence of emergency vehicles; and

, said terminal interface equipment includes means for disabling said local controller means in response to the detection of an emergency vehicle by said emergency vehicle-detector means.

18. An automated traffic control system as in claim 17, wherein:

said remote terminal means includes sequencing means for rendering said mean for disabling said local controller means inoperative until after a prescribed signal is received from said central control facility.

19. An automated traffic control system as in claim 17, wherein:

said terminal interface equipment includes means for causing said traffic control means to produce a signal indicative of the presence of an emergency vehicle.

20. An automated traffic control system As in claim 14, wherein:

said traffic control means include indicator lamp means for producing visual traffic regulating signals.

21. An automated traffic control system as in claim 14, wherein:

said remote terminal means include signal generator means for generating a signal in response to said traffic control means becoming inoperative.

22. An automated traffic control system as in claim 13, wherein:

said remote terminal means include vehicle detector means coupled to said remote transceiver means for measuring parameters of traffic flow.

23. An automated traffic control system as in claim 13, wherein:

said remote terminal means include emergency vehicle detector means coupled to said remote transceiver means for sensing the presence of emergency vehicles.

24. An automated traffic control system as in claim 13, wherein:

said remote transceiver means includes data receiver means for accepting said traffic control signals from said central control facility.

25. An automated traffic control system as in claim 24, wherein:

said remote transceiver means includes coarse synchronization signal detecting means for preparing said data receiver means to receive traffic control signals from said central control facility.

26. An automated traffic control system as in claim 24, wherein:

said remote transceiver means includes fine synchronization signal detecting means for preparing said data receiver means to decode traffic control signals from said central control facility.

27. An automated traffic control system as in claim 26, wherein:

said fine synchronization signal detecting means includes means for establishing a stable reference signal for demodulation of said traffic control signals from said central control facility.

28. An automated traffic control system as in claim 27, wherein:

said fine synchronization signal detecting means includes phase sensitive means for determining whether said stable reference signal is in phase with a signal from said central control facility, or 180* out of phase with said signal from said central control facility.

29. An automated traffic control system as in claim 27, wherein:

said remote transceiver means includes response modulator means for producing pulse amplitude modulation of said stable reference signal.

30. An automated traffic control system as in claim 13, wherein:

said remote transceiver means includes logic means for demultiplexing said traffic control signals from said central control facility and for multiplexing said input information signals for transmission to said central control facility.

31. An automated traffic control system as in claim 13, wherein:

said remote terminal means include vehicle sensing means for detecting the presence of vehicles.

32. An automated traffic control system as in claim 13, wherein:

said remote terminal means include vehicle counting means for determining the number of passing vehicles.

33. An automated traffic control system as in claim 13, wherein:

said remote terminal means include vehicle speed detectors for determining the speeds of passing vehicles.