Optimization of Vehicular Traffic Flow through a Conflict Zone

• US 20100134320A1
• Filed: 12/01/2008
• Published: 06/03/2010
• Est. Priority Date: 12/01/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ramm, Dov, Chevion, Dan Shmuel, Shimony, Yuval, Sivan, Ron
• Granted Patent: US 7,969,324 B2
• Time in Patent Office: Days
• US Class Current: 340/932
• CPC Class Codes: G08G 1/164 Centralised systems, e.g. external to vehicles

Abstract

An automatic vehicular traffic flow control technique defines a controlled area, wherein vehicles belonging to different traffic streams contend for occupancy of a conflict zone. A traversal order is computed for the vehicles in the controlled area, wherein the ordered vehicles are assigned to traverse the conflict zone sequentially in accordance with their respective positions in the traversal order. Tracking and tracked vehicles are designated, wherein a respective tracked vehicle immediately precedes each of the tracking vehicles in the traversal order. The tracking vehicles maintain a specified physical relationship with their respective tracked vehicles until the tracked vehicle has traversed the conflict zone. The speed of the traffic streams is increased as necessary so as to achieve a desired throughput through the conflict zone.

Claims

1. A method of automatic vehicular traffic flow control, comprising the steps of:

defining a controlled area that includes a conflict zone having a plurality of vehicular traffic streams passing therethrough in different directions and entering the controlled area at respective initial speeds, wherein vehicles belonging to different ones of the vehicular traffic streams contend for occupancy of the conflict zone; and

interleaving the vehicular traffic streams at the conflict zone under automatic control while varying respective zone speeds of the vehicular traffic streams such that the vehicular traffic streams freely flow through the conflict zone without traffic backup, wherein the zone speeds are not less than the respective initial speeds.

2. The method according to claim 1, wherein varying respective zone speeds comprises accelerating the vehicles prior to reaching the conflict zone and decelerating the vehicles subsequent to passage therethrough.

3. The method according to claim 2, wherein accelerating and decelerating the vehicles cause the vehicles to exit the controlled area at the respective initial speeds.

4. The method according to claim 1, wherein varying respective zone speeds comprises adjusting the zone speeds of the vehicular traffic streams so as to achieve a desired throughput through the conflict zone.

5. The method according to claim 1, wherein varying respective zone speeds comprises adjusting the zone speeds of the vehicular traffic streams so as to achieve desired respective inter-vehicle gaps in the vehicular traffic streams at the conflict zone.

6. The method according to claim 1, further comprising the steps of dynamically adjusting a size of the controlled area responsively to a momentary density of the vehicular traffic streams to accommodate a desired scheme of acceleration and deceleration of the vehicular traffic streams.

7. The method according to claim 1, further comprising the steps of:

computing a traversal order for the vehicles that are located within the controlled area to define ordered vehicles; and

causing the ordered vehicles to traverse the conflict zone sequentially in accordance with their respective positions in the traversal order.

8. The method according to claim 1, wherein interleaving the vehicular traffic streams comprises forming convoys within the streams and interleaving the convoys.

9. A computer software product for use in automatic vehicular traffic flow control, including a computer storage medium in which computer program instructions are stored, which instructions, when executed by a computer, cause the computer to define a controlled area that includes a conflict zone having a plurality of vehicular traffic streams passing therethrough in different directions and entering the controlled area at respective initial speeds, wherein vehicles belonging to different ones of the streams contend for occupancy of the conflict zone, interleave the vehicular traffic streams at the conflict zone while varying respective zone speeds of the vehicular traffic streams such that the vehicular traffic streams freely flow through the conflict zone without traffic backup, wherein the zone speeds are not less than the respective initial speeds.

10. The computer software product according to claim 9, wherein the computer is instructed to issue command signals that cause the vehicles to accelerate prior to reaching the conflict zone and decelerate the vehicles subsequent to passage therethrough.

11. The computer software product according to claim 10, wherein the command signals cause the vehicles to exit the controlled area at the respective initial speeds.

12. The computer software product according to claim 10, wherein the command signals control the zone speeds of the vehicular traffic streams so as to achieve a desired throughput through the conflict zone.

13. The computer software product according to claim 10, wherein the command signals control the zone speeds of the vehicular traffic streams so as to achieve desired respective inter-vehicle gaps in the vehicular traffic streams at the conflict zone.

14. The computer software product according to claim 9, wherein the computer is further instructed to dynamically adjust a size of the controlled area responsively to a momentary density of the vehicular traffic streams to accommodate a desired scheme of acceleration and deceleration of the vehicular traffic streams.

15. A traffic control system for automatic vehicular traffic flow control, comprising:

a transmitter;

a receiver;

an area processor for controlling a plurality of vehicular traffic streams passing through a conflict zone in different directions, wherein vehicles belonging to different ones of the streams contend for occupancy of the conflict zone; and

a memory, accessible to the processor, storing program instructions, which instructions, when executed by the processor, cause the processor to define a controlled area that includes the conflict zone, wherein the vehicular traffic streams enter the controlled area at respective initial speeds, and wherein the processor is operative to control the vehicular traffic streams so as to interleave the vehicular traffic streams at the conflict zone; and

issue command signals, causing the vehicles to vary respective zone speeds such that the vehicular traffic streams freely flow through the conflict zone without traffic backup and wherein the zone speeds are not less than the respective initial speeds.

16. The traffic control system according to claim 15, wherein the command signals accelerate the vehicles prior to reaching the conflict zone and decelerate the vehicles subsequent to passage therethrough.

17. The traffic control system according to claim 16, wherein the command signals cause the vehicles to exit the controlled area at the respective initial speeds.

18. The traffic control system according to claim 15, wherein the command signals control the zone speeds of the vehicular traffic streams so as to achieve a desired throughput through the conflict zone.

19. The traffic control system according to claim 15, wherein the command signals control the zone speeds of the vehicular traffic streams so as to achieve desired respective inter-vehicle gaps in the vehicular traffic streams at the conflict zone.

20. The traffic control system according to claim 15, wherein the instructions further cause the processor to dynamically adjust a size of the controlled area responsively to a momentary density of the vehicular traffic streams to accommodate a desired scheme of acceleration and deceleration of the vehicular traffic streams.

21. A method of automatic vehicular traffic flow control, comprising the steps of:

defining a controlled area that includes a conflict zone having a plurality of vehicular traffic streams passing therethrough, including a first stream and a second stream, wherein vehicles belonging to different ones of the streams contend for occupancy of the conflict zone;

computing a traversal order for the vehicles that are located within the controlled area to define ordered vehicles, wherein the ordered vehicles are assigned to traverse the conflict zone sequentially in accordance with their respective positions in the traversal order,

designating, among the ordered vehicles, tracking vehicles and a respective tracked vehicle for each of the tracking vehicles, wherein the respective tracked vehicle immediately precedes each of the tracking vehicles in the traversal order, and wherein at least a portion of the tracking vehicles belong to the first stream and their respective tracked vehicles belong to the second stream; and

causing each of the tracking vehicles to maintain a specified physical relationship with the respective tracked vehicle thereof, until the respective tracked vehicle has traversed the conflict zone.

22. The method according to claim 21, wherein the traversal order is a total ordering, which defines unambiguously, for any pair of the vehicles, which of the pair is to be first in traversing the conflict zone.

23. The method according to claim 21, further comprising the step of preventing the tracking vehicles from entering the conflict zone until their respective tracked vehicles have crossed the conflict zone.

24. The method according to claim 21, wherein the specified physical relationship is a function of distances to the conflict zone of the tracking vehicles and their respective tracked vehicles.

25. The method according to claim 21, wherein the tracking vehicles and their respective tracked vehicles approach the conflict zone from different directions.

26. The method according to claim 21, further comprising maintaining a constant speed of the streams through the conflict zone.

27. The method according to claim 21, further comprising the step of:

adjusting boundaries of the controlled area responsively to a momentary traffic density in the streams.

28. A computer software product for automatic vehicular traffic flow control, including a computer storage medium in which computer program instructions are stored, which instructions, when executed by a computer, cause the computer to define a controlled area that includes a conflict zone, monitor a plurality of vehicular traffic streams passing through the conflict zone, including a first stream and a second stream, wherein vehicles belonging to different ones of the streams contend for occupancy of the conflict zone, compute a traversal order for the vehicles that are located within the controlled area to define ordered vehicles, wherein the ordered vehicles are assigned to traverse the conflict zone sequentially in accordance with their respective positions in the traversal order, designate, among the ordered vehicles, tracking vehicles and a respective tracked vehicle for each of the tracking vehicles, wherein the respective tracked vehicle immediately precedes each of the tracking vehicles in the traversal order, and wherein at least a portion of the tracking vehicles belong to the first stream and their respective tracked vehicles belong to the second stream, and cause each of the tracking vehicles to maintain a specified physical relationship with the respective tracked vehicle thereof, until the respective tracked vehicle has traversed the conflict zone.

29. A traffic control system for automatic vehicular traffic flow control, comprising:

a transmitter;

a receiver;

an area processor for controlling a plurality of vehicular traffic streams passing through a conflict zone, including a first stream and a second stream, wherein vehicles belonging to different ones of the streams contend for occupancy of the conflict zone; and

a memory, accessible to the processor, storing program instructions, which instructions, when executed by the processor, cause the processor to define a controlled area that includes the conflict zone, to receive messages via the receiver from tracking vehicles in the streams that are passing through the controlled area, the messages comprising location information of the respective tracking vehicles, compute a traversal order for the tracking vehicles to traverse the conflict zone sequentially in accordance with their respective positions in the traversal order, and to transmit control signals via the transmitter, wherein the control signals cause the tracking vehicles to maintain a specified physical relationship with respective tracked vehicles until the tracked vehicles traverse the conflict zone, wherein the tracked vehicles immediately precede the tracking vehicles in the traversal order, respectively, and wherein at least a portion of the tracking vehicles belong to the first stream and their respective tracked vehicles belong to the second stream.