Centralized traffic signal preemption system and method of use

• US 6,909,380 B2
• Filed: 04/04/2003
• Issued: 06/21/2005
• Est. Priority Date: 04/04/2003
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Brooke, O'Neil
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US10/406,250
• Publication Number:
  US 20040196162A1
• Time in Patent Office: 809 Days
• Field of Search: 340/902, 340/904, 340/905, 340/906, 340/907, 340/909, 340/910, 340/914, 340/917, 340/988, 701/117, 701/118, 701/119, 701/220
• US Class Current: 340/906
• CPC Class Codes: G08G 1/087 Override of traffic control, e.g. by signal transmitted by an emergency vehicle
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles

Abstract

A system and method of centralizing traffic signal preemption for roadway emergency operations provides for increased accuracy and coordination of emergency response vehicles along an emergency route. A centralized preemption system receives status and location information, e.g., GPS, from emergency vehicles via fleet management systems or dispatch centers. As an emergency route is determined and projected in real-time, predetermined policies are applied to create an overall preemption plan of traffic lights at intersections along an anticipated route. The preemption plan results in preemption directives being transmitted to traffic management systems that are controlling traffic signal controllers at intersections along the route. The centralized preemption system may coordinate among many traffic management systems that provides for a much larger preemption service area including multiple jurisdictions.

Claims

1. A method for preempting traffic signals at intersections, the method comprising:

transmitting status information from a vehicle including a request for preemption to a centralized preemption system;

determining a preemption plan by the centralized preemption system using policy rules and the status information; and

sending a preemption directive to one or more traffic signal controllers related to a route,

wherein the preemption directive causes the traffic signal controllers to alter a traffic signal cycle along the route based on results of the determining step.

2. The method of claim 1, further comprising the steps of:

monitoring vehicle location for changes in vehicle location; and

revalidating the preemption plan as the vehicle transmits new status information.

3. The method of claim 1, further comprising the step of determining a route based on the preemption plan.

4. The method of claim 3, further comprising the step of sending the route to the vehicle.

5. The method of claim 1, wherein the policy rules include at least one of:

(i) whether a traffic signal is controlled by a traffic management system,

(ii) intersections involved,

(iii) agency requesting preemption,

(iv) type of vehicle involved,

(v) type of emergency,

(vi) level of an emergency,

(vii) location,

(viii) destination of the vehicle,

(ix) time-of-day, day of week, whether it is a holiday, whether it is a work day,

(x) traffic density,

(xi) requested route,

(xii) proposed route,

(xiii) direction,

(xiv) agency requesting preemption, and

(xv) speed.

6. The method of claim 1, wherein the status information includes at least one of location, agency requesting preemption, type of vehicle involved, mode of operation, destination, route request, level of emergency, speed, direction, traffic conditions and operational condition.

7. The method of claim 1, wherein the step of the sending preemption directive further includes sending the preemptive directive to one or more traffic management systems, the traffic management systems are in communication with the one or more traffic signal controllers.

8. The method of claim 7, wherein the traffic management system sends one of a modified and a non-modified preemptive directive to the one or more traffic signal controllers to alter traffic signal cycles along the route, and wherein the traffic signal cycles along the route return to normal operations.

9. The method of claim 1, wherein the route is developed according to a requested destination of the vehicle and the preemptive directive is issued based in part on projected arrival times of the vehicle at one or more intersections.

10. The method of claim 1, wherein the one or more traffic signal controllers are two or more traffic signal controllers of different models and the centralized preemption system translates the preemption directive into a format appropriate for each of the two or more traffic signal controllers of different models.

11. The method of claim 1, wherein the one of more traffic signal controllers are at least two or more traffic signal controllers, at least one of which is associated with a different jurisdiction.

12. The method of claim 1, wherein the policy rules are comprehensive policy rules that include policies from different localities and the preemptive directives are coordinated according to the policies from the different localities.

13. The method of claim 1, wherein the preemption plan is cross-checked with another preemption plan to check for conflicts in routes.

14. The method of claim 1, wherein the sending step includes sending the preemption directive to the one or more traffic signal controllers in a proper format when the equipment in the vehicle is incompatible with the traffic signal controllers.

15. The method of claim 1, further comprising requesting a best route to be determined by the centralized preemption system.

16. The method of claim 1, wherein the route is a projected path for the vehicle to traverse to reach a known destination and the route is known to both the central preemption system and the vehicle.

17. A method for preempting traffic signals at intersections for emergency vehicles, the method comprising:

transmitting status information including a request for preemption from a vehicle;

receiving the status information at a management system, the management system determining which one or more centralized preemption systems receives the status information;

retransmitting the status information to the determined one or more centralized preemption systems;

determining a preemption plan by the one or more determined centralized preemption systems using policy rules and the status information; and

sending a preemption directive according to the preemption plan to one or more traffic signal controllers related to a route to thereby coordinate the one or more traffic signal controllers.

18. The method of claim 17, the step of the sending preemption directive includes sending the preemptive directive to one or more traffic management systems, the traffic management systems in communication with the one or more traffic signal controllers.

19. The method of claim 18, wherein the traffic management system sends one of a modified and a non-modified preemptive directive to the one or more traffic signal controllers to alter traffic signal cycles along the route, and then returns the traffic signal cycles along the route to normal operations.

20. The method of claim 17, wherein the status information includes at least one of location, agency requesting preemption, type of vehicle involved, mode of operation, destination, destination request, requested route, level of emergency, speed, direction, and operational condition.

21. The method of claim 17, wherein the preemption plan identifies at least the traffic management systems and traffic light signal controllers that are involved along a route and the preemption plan determines the preemption timing pattern for the traffic signal controllers.

22. The method of claim 17, wherein the policy rules include at least one of:

(i) whether a traffic signal is controlled by a traffic management system,

(ii) intersections involved,

(iii) an agency requesting preemption,

(iv) type of vehicle involved,

(v) type of emergency,

(vi) severity of an emergency,

(vii) location of the vehicle,

(viii) destination of the vehicle,

(ix) time-of-day, day of week, whether it is a holiday, whether it is a work day,

(x) traffic density,

(xi) requested emergency route,

(xii) proposed route,

(xiii) speed, and

(xiv) direction.

23. The method of claim 17, further comprising the step of revalidating the route as subsequent status information arrives from the vehicle.

24. The method of claim 17, further comprising the step of sending a determined route to the vehicle according to the preemption plan.

25. The method of claim 17, wherein the preemption directive causes the traffic signal controllers to alter a traffic signal cycle.

26. The method of claim 17, wherein the determining a preemption plan step includes using a geophysical subsystem for tracking and associating the vehicle location along one or more routes.

27. The method of claim 17, wherein the management system is at least one of a fleet management system, a caller and dispatch system, and a centralized preemption system.

28. A system for centralizing traffic signal preemption, the system comprising:

a component for receiving status information including a request for preemption from an vehicle at a management system that determines which one or more centralized management systems should receive the status information;

a component for retransmitting the status information to the determined one or more centralized preemption systems;

a component for determining a route and a preemption plan using policy rules and the status information; and

a component for sending a preemption directive according to the preemption plan to one or more traffic signal controllers related to the route,

wherein the preemptive directives alters a traffic signal cycle.

29. The system of claim 28, wherein the policy rules include at least one of:

(i) whether a traffic signal is controlled by a traffic management system,

(ii) intersections involved,

(iii) an agency requesting preemption,

(iv) type of vehicle involved,

(v) type of emergency,

(vi) severity of an emergency,

(vii) location of the vehicle,

(viii) destination of the vehicle,

(ix) time-of-day, day of week, whether it is a holiday, whether it is a work day,

(x) traffic density,

(xi) requested emergency route

(xii) proposed route,

(xiii) speed, and

(xiv) direction,

wherein the status information includes at least one of location, agency requesting preemption, type of vehicle involved, mode of operation, destination, requested route, level of emergency, speed, direction, traffic conditions and operational condition.