Control of traffic signal phases
Controlling a traffic signal phase at one or more intersections. A control system at an intersection is configured to operate in one of a first mode or a second mode. While operating the controller in the first mode, in response to a transit priority signal received by the control system from a vehicle assigned transit priority, a green phase of the traffic signal is extended in favor of the vehicle assigned transit priority. While operating the control system in the second mode, in response to a transit priority signal received by the control system from the vehicle assigned transit priority, a current non-green phase of the traffic signal is preempted to a green phase in favor of the vehicle assigned transit priority.
1. A method for controlling a traffic signal phase at one or more intersections, respectively, comprising:
configuring a control system at an intersection to operate in one of a first mode or a second mode;
wherein the configuring of the control system to operate in the second mode includes storing data indicative of an evacuation direction;
while operating the control system in the first mode, in response to a transit priority signal received by the control system from a vehicle assigned transit priority, extending a green phase of the traffic signal in favor of the vehicle assigned transit priority; and
while operating the control system in the second mode, in response to a transit priority signal received by the control system from the vehicle assigned transit priority, preempting a current non-green phase of the traffic signal to a green phase in favor of the vehicle assigned transit priority;
wherein the preempting of the current non-green phase of the traffic signal is denied to the vehicle assigned transit priority unless the vehicle assigned transit priority is traveling in the evacuation direction.
2. The method of claim 1 , wherein while operating the control system in the second mode, in response to a transit priority signal received by the control system from the vehicle assigned transit priority, extending a current green phase of the traffic signal phase in favor of the vehicle assigned transit priority.
3. The method of claim 1 , further comprising:
wherein the configuring of the control system to operate in the second mode includes storing one or more respective vehicle identifiers for one or more vehicles assigned transit priority; and
while operating the control system in the second mode, in response to a transit priority signal received by the control system from a vehicle assigned transit priority and not having a stored vehicle identifier, continuing a current traffic signal phase without preempting a current non-green phase of the traffic signal phase.
4. The method of claim 1 , wherein:
the configuring of the control system to operate in the second mode includes storing data indicating a start date and a stop date; and
the preempting of the current non-green phase of the traffic signal is denied to the vehicle assigned transit priority unless the transit priority signal received by the control system is received between the start date and stop date.
5. The method of claim 4 , wherein:
the configuring of the control system to operate in the second mode includes storing data indicating a start time and a stop time; and
the preempting of the current non-green phase of the traffic signal phase is denied to the vehicle assigned transit priority unless the transit priority signal received by the control system is received between the start time and stop time.
6. The method of claim 1 , wherein:
the configuring of the control system to operate in the second mode includes storing data indicative of the evacuation direction;
the preempting of the current non-green phase of the traffic signal is denied to the vehicle assigned transit priority unless the vehicle assigned transit priority is traveling in the evacuation direction; and
in response to receiving an emergency priority signal by the control system from an emergency vehicle traveling in a direction other than the evacuation direction concurrent with receiving the transit priority signal from the vehicle assigned transit priority traveling in the evacuation direction, preempting a current non-green phase of the traffic signal to a green phase in favor of the emergency vehicle.
7. The method of claim 1 , further comprising:
inputting evacuation plan data that specify one or more intersections to a centralized management system; and
wherein the configuring includes the centralized management system configuring respective controllers at each of the one or more intersections to operate in the second mode.
8. The method of claim 7 , wherein:
the evacuation plan data include a start date, a start time, a stop date, and a stop time;
the preempting of the current non-green phase of the traffic signal phase is denied to the vehicle assigned transit priority unless the transit priority signal received by the control system is received between the start time on the start date and the stop time on the stop date; and
the configuring includes the centralized management system configuring respective controllers at each of the one or more intersections to operate in the second mode in response to passing of the start time on the start date.
9. The method of claim 8 , wherein the configuring of each controller by the centralized management system includes downloading a duration value that specifies a period of time for which the controller is to operate in the second mode before reverting to the first mode.
10. The method of claim 8 , further comprising the centralized management system configuring respective controllers at each of the one or more intersections to operate in the first mode in response to passing of the stop time on the stop date.
11. The method of claim 7 , further comprising, in response to input to the centralized management system of a cancellation request that references the evacuation plan data, the centralized management system configuring respective controllers at each of the one or more intersections to operate in the first mode.
12. A system for controlling a traffic signal phase at an intersection, comprising:
a control system at an intersection configurable to operate in one of a first mode or a second mode;
wherein the control system is configurable to store data indicative of an evacuation direction;
two or more traffic signals coupled to the control system;
wherein the control system is configured to:
extend, in response to a transit priority signal received from a vehicle assigned transit priority while the control system is operating in the first mode, a green phase of one of the two or more traffic signals in favor of the vehicle assigned transit priority; and
preempt, in response to a transit priority signal received by the control system from the vehicle assigned transit priority while the control system is operating the control system in the second mode, a current non-green phase of the one of the two or more traffic signals to a green phase in favor of the vehicle assigned transit priority;
wherein the control system is further configured to deny the preempting of the current non-green phase of the one of the two or more traffic signals to the vehicle assigned transit priority unless the vehicle assigned transit priority is traveling in the evacuation direction.
13. The system of claim 12 , wherein the control system is further configured to extend, in response to a transit priority signal received by the control system from the vehicle assigned transit priority while the control system is operating in the second mode, a current green phase of the one of the two or more traffic signals in favor of the vehicle assigned transit priority.
14. The system of claim 12 , wherein:
the control system is configurable to store one or more respective vehicle identifiers for one or more vehicles assigned transit priority; and
the control system is further configured to continue, in response to a transit priority signal received by the control system from a vehicle assigned transit priority and not having a stored vehicle identifier while the control system is operating in the second mode, a current traffic signal phase without preempting a current non-green phase of the one of the two or more traffic signals.
15. The system of claim 12 , wherein:
the control system is configurable to store data indicating a start date and a stop date; and
the control system is further configured to deny the preempting of the current non-green phase of the one of the two or more traffic signals to the vehicle assigned transit priority unless the transit priority signal received by the control system is received between the start date and stop date.
16. The system of claim 15 , wherein:
the control system is configurable to store data indicating a start time and a stop time; and
the control system is further configured to deny the preempting of the current non-green phase of the one of the two or more traffic signals to the vehicle assigned transit priority unless the transit priority signal received by the control system is received between the start time and stop time.
17. The system of claim 12 , wherein:
the control system is configurable to store data indicative of the evacuation direction;
the control system is further configured to deny the preempting of the current non-green phase of the one of the two or more traffic signals to the vehicle assigned transit priority unless the vehicle assigned transit priority is traveling in the evacuation direction; and
the control system is further configured to preempt, in response to receiving an emergency priority signal by the control system from an emergency vehicle traveling in a direction other than the evacuation direction concurrent with receiving the transit priority signal from the vehicle assigned transit priority traveling in the evacuation direction, a current non-green phase of the one of the two or more traffic signals to a green phase in favor of the emergency vehicle.
18. A system for controlling traffic signal phases of a plurality of respective sets of two or more traffic signals at a plurality of intersections, comprising:
a management system;
a plurality of control systems at the plurality of intersections, respectively, each control system coupled to the management system and individually configurable via the management system to operate in one of a first mode or a second mode;
wherein each control system is coupled to one of the respective sets of two or more traffic signals, each control system is configurable to store data indicative of an evacuation direction, and each control system is configured to:
extend, in response to a transit priority signal received from a vehicle assigned transit priority while the control system is operating in the first mode, a green phase of one traffic signal of the respective set of two or more traffic signals in favor of the vehicle assigned transit priority; and
preempt, in response to a transit priority signal received by the control system from the vehicle assigned transit priority while the control system is operating in the second mode, a current non-green phase of the one traffic signal of the respective set of two or more traffic signals to a green phase in favor of the vehicle assigned transit priority,
deny the preempting of the current non-green phase of the one of the two or more traffic signals to the vehicle assigned transit priority unless the vehicle assigned transit priority is traveling in the evacuation direction.
19. The method of claim 1 , further comprising, while operating the control system in the first mode, in response to the transit priority signal received by the control system from the vehicle assigned transit priority, not preempting the current non-green phase of the traffic signal to a green phase in favor of the vehicle assigned transit priority.
20. The system of claim 12 , wherein the control system is further configured to not preempt, in response to the transit priority signal received by the control system from the vehicle assigned transit priority while the control system is operating in the first mode, the current non-green phase of the one traffic signal of the respective set of two or more traffic signals to a green phase in favor of the vehicle assigned transit priority.
21. The system of claim 18 , wherein each control system is further configured to not preempt, in response to the transit priority signal received by the control system from the vehicle assigned transit priority while the control system is operating in the first mode, the current non-green phase of the one traffic signal of the respective set of two or more traffic signals to a green phase in favor of the vehicle assigned transit priority.