Forwarding system for long-range preemption and corridor clearance for emergency response

• US 20050264431A1
• Filed: 09/15/2004
• Published: 12/01/2005
• Est. Priority Date: 04/09/2002
• Status: Abandoned Application

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Bachelder, Aaron D.
• Application Number:
  US10/942,498
• Publication Number:
  US 20050264431A1
• Time in Patent Office: Days
• US Class Current: 340/906
• 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

Systems for and methods of preempting intersections by forwarding preemption requests from one intersection to another are described. In one aspect of the invention, congestion can be cleared from the path of a preempting vehicle by facilitating the flow of traffic in front of the vehicle. In another aspect of the invention a preemption corridor is created. Additionally, the preemption corridor can be further cleared by preempting side streets to the preemption corridor. One embodiment of the invention includes a microcontroller configured to receive forwarded preemption requests from a network. In addition, the microcontroller is configured to evaluate information included in a preemption request against a predetermined set of criteria and the microcontroller is configured to preempt a sequence of traffic signals when the information forwarded in a preemption request satisfies the predetermined set of criteria.

Claims

1. A traffic signal controller, comprising;

a microcontroller configured to receive forwarded preemption requests from a network; and

wherein the microcontroller is configured to evaluate information included in a preemption request against a predetermined set of criteria; and

wherein the microcontroller is configured to preempt a sequence of traffic signals when the information forwarded in a preemption request satisfies the predetermined set of criteria.

2. The traffic signal controller of claim 1, further comprising:

an intersection controller having preemption inputs;

a long-range preemption module that is connected to the intersection controller preemption inputs and which includes the microcontroller and a transceiver; and

a preemption device connected to the long range preemption module;

wherein the network is a wireless network.

3. The traffic signal controller of claim 1, further comprising:

an intersection controller having preemption inputs;

a long-range preemption module that is connected to the intersection controller preemption inputs and which includes the microcontroller and a network interface; and

a preemption device connected to the long range preemption module;

wherein the network is a wired network.

4. The traffic signal controller of claim 1, further comprising:

an intersection controller including the microcontroller and having preemption inputs;

a preemption device connected to the intersection controller via the preemption inputs;

a transceiver connected to the intersection controller;

wherein the network is a wireless network.

5. The traffic signal controller of claim 1, further comprising:

an intersection controller including the microcontroller and having preemption inputs;

a preemption device connected to the intersection controller via the preemption inputs;

a network interface connected to the intersection controller;

wherein the network is a wired network.

6. The traffic signal controller of claim 1, wherein:

the preemption request is forwarded from a traffic signal controller that includes an intersection controller;

the traffic signal controller is located at a preempted intersection;

the forwarded preemption request includes information concerning;

the geographic location of the preempted intersection; and

the state of the preemption inputs of the intersection controller of the preempted intersection.

7. The traffic signal controller of claim 1, wherein:

the forwarded preemption request was generated in response to a preempting vehicle;

the microprocessor is configured to evaluate the information by generating an estimated time of arrival for the preempted vehicle using a velocity window.

8. The traffic signal controller of claim 7, wherein the microprocessor is configured to evaluate the information by determining the velocity window based on present traffic conditions.

9. The traffic signal controller of claim 1, wherein the microprocessor is configured to resolve preemption requests made directly to the traffic signal controller by a vehicle and forwarded preemption requests.

10. The traffic signal controller of claim 9, wherein:

the preemption request from the vehicle and the forwarded preemption request include priority information; and

the microprocessor is configured to preempt a traffic signal sequence in a manner consistent with the highest priority preemption request.

11. A traffic signal controller, comprising:

means for receiving forwarded preemption requests;

means for evaluating the appropriateness of a forwarded preemption request; and

means for preempting traffic signals in response to an appropriate forwarded preemption request.

12. The traffic signal controller of claim 11, further comprising:

means for receiving direct preemption requests; and

means for resolving conflicts between direct preemption requests and forwarded preemption requests.

13. A traffic signal control system, comprising:

a plurality of traffic signal controllers;

wherein at least one traffic signal controller includes a preemption device that can be preempted by a vehicle equipped with hardware capable of communicating a preemption request to the preemption device;

wherein the traffic signal controller is configured to send a forwarded preemption requests via a network;

wherein at least one of the traffic signal controllers is configured to receive the forwarded preemption request via the network.

14. The traffic signal control system of claim 13, wherein the network is wireless.

15. The traffic signal control system of claim 13, wherein the network is wired.

16. A method of preempting an intersection, comprising:

receiving a preemption request forwarded from another intersection;

determining whether the forwarded preemption request satisfies at least one predefined criteria;

determining whether the forwarded preemption request conflicts with any preemption request currently being honored by the intersection;

when the preemption request satisfies the predefined criteria and does not conflict with other preemption requests, preempting the intersection and forwarding the preemption request to neighboring intersections.

17. The method of claim 16, wherein the preemption request includes information concerning the geographic location of the intersection that is the source of the preemption request and the manner in which the preempted intersection has been preempted.

18. The method of claim 16, wherein:

the forwarded preemption request was originated at an originating intersection;

determining whether the forwarded preemption request satisfies at least one predefined criteria comprises determining whether the originating intersection is within a predetermined distance of the intersection.

19. The method of claim 16, wherein:

a vehicle preempted an originating intersection that forwarded the preemption request;

determining whether the forwarded preemption request satisfies at least one predefined criteria comprises determining whether the vehicle will arrive at the intersection with sufficient probability.

20. The method of claim 16, wherein:

a vehicle preempted an originating intersection that forwarded the preemption request;

determining whether the forwarded preemption request satisfies at least one predefined criteria comprises determining whether the vehicle will arrive at the intersection within a predetermined time.

21. The method of claim 16, wherein:

the forwarded preemption request is assigned a priority;

other preemption requests are also assigned priorities;

determining whether the forwarded preemption request conflicts with any preemption request currently being honored by the intersection comprises determining whether the forwarded preemption request is of a higher priority than all other preemption requests.

22. The method of claim 21, wherein the other preemption requests can include at least one preemption request made directly to the intersection by a vehicle.

23. The method of claim 21, wherein the other preemption requests can include at least one other preemption request forwarded to the intersection by another intersection.

24. The method of claim 16, wherein preempting the intersection comprises establishing both traffic and pedestrian signals in accordance with the preemption request.

25. The method of claim 16, wherein forwarding the preemption request to neighboring intersections involves broadcasting the preemption request over a wireless network.

26. The method of claim 16, wherein forwarding the preemption request to neighboring intersections involves sending the preemption request to neighboring intersections via a wired network.