Traffic preemption system with headway management
A traffic-preemption system and method that communicates an identification code from vehicles to a traffic location. Traffic light control equipment, such as a receiver and traffic light circuit at each intersection of a controlled area, is used to manage headway in mass-transit systems as well as to provide traffic light pre-emption for emergency vehicles. Each traffic light circuit in the controlled area has a receiver located at a traffic location and adapted to receive an identification code from a mass-transit vehicle. A decoding circuit responds to the received identification code by attempting to identify the mass-transit vehicle and determine the timing on the identified route that improves an identified vehicle's headway and/or route timing. In response to determining the timing, a traffic-preemption command is generated for a traffic light on the identified route.
1. A traffic-preemption system, comprising:
a transmitter adapted to transmit an identification code of a mass-transit vehicle; and
a traffic light circuit having
receiver located at a traffic location and adapted to receive the identification code, and
a decoding circuit adapted to attempt to identify the mass-transit vehicle using the identification code, compare a time of the mass-transit vehicle's arrival at the traffic location with a pre-determined schedule, and, in response to determining a variance between the time of arrival and the pre-determined schedule, generate a traffic-preemption command for a traffic light.
2. The traffic-preemption system of claim 1 , wherein the decoding circuit is further adapted to generate the traffic-preemption command for a traffic light at the traffic location.
3. The traffic-preemption system of claim 1 , wherein the decoding circuit is further adapted to generate the traffic-preemption command for a traffic light at a traffic location further along the mass-transit vehicle's route.
4. The traffic-preemption system of claim 1 , wherein the decoding circuit is further adapted to generate the traffic-preemption command for a traffic light based on a preemption hierarchy.
5. The traffic-preemption system of claim 1 , wherein the receiver is further adapted to receive an identification code from a second mass-transit vehicle; and the decoding circuit is further adapted to attempt to identify the second mass-transit vehicle, compare a time of the second mass-transit vehicle's arrival at the traffic location with a pre-determined schedule, and, in response to determining a variance between the time of arrival and the pre-determined schedule for both mass-transit vehicles, generate a traffic-preemption command for a traffic light based on the mass-transit vehicle having the largest variance.
6. The traffic-preemption system of claim 1 , wherein the mass-transit vehicle further comprises a receiver configured to facilitate two-way communications between the mass-transit vehicle and the traffic light circuit, whereby variance information may be communicated to the mass-transit vehicle.
7. A method for managing headway of a mass-transit vehicle at a traffic location in a traffic-preemption system, comprising:
transmitting an identification code from a transmitter associated with the mass-transit vehicle;
receiving the identification code at a receiver situated at the traffic location;
identifying the mass-transit vehicle using the identification code;
comparing a time of the mass-transit vehicle's arrival at the traffic location with a predetermined schedule;
determining a variance between the time of arrival and the pre-determined schedule; and
generating a traffic-preemption command for a traffic light based on the determined variance.
8. The method of claim 7 , further comprising generating the traffic-preemption command for the traffic light in response to the determined variance exceeding a threshold.
9. The method of claim 7 , wherein the traffic-preemption command is generated for the traffic light at the traffic location.
10. The method of claim 7 , wherein the traffic-preemption command is generated for the traffic light at a traffic location further along the mass-transit vehicle's route.
11. The method of claim 7 , wherein the traffic-preemption command is generated based on a preemption hierarchy.
12. The method of claim 7 , wherein the traffic-preemption command is generated to facilitate regular intervals between the mass-transit vehicle and other mass-transit vehicles.
13. The method of claim 7 , wherein the traffic-preemption command is generated to facilitate schedule adherence by the mass-transit vehicle.
14. A traffic-preemption system, comprising:
a first transceiver associated with a mass-transit vehicle and adapted to transmit an identification code of the mass-transit vehicle and receive encoded information; and
a controller provided at each one of a plurality of intersections;
a respective second transceiver coupled to each controller and adapted to receive the transmitted identification code from the first transceiver and to transmit the encoded information to the first transceiver; and
a respective decoding circuit coupled to each controller and adapted to attempt to identify the mass-transit vehicle using the identification code;
wherein the controller is adapted to compare a time of the mass-transit vehicle's arrival at the one of the intersections with a pre-determined schedule, and, in response to determining a variance between the time of arrival and the pre-determined schedule, generate a traffic-preemption command for a traffic light and transmit variance information to the mass-transit vehicle.
15. The traffic-preemption system of claim 14 , wherein the controller is further adapted to generate the traffic-preemption command for a traffic light at the mass-transit vehicle's present intersection.
16. The traffic-preemption system of claim 14 , wherein the controller is further adapted to generate the traffic-preemption command for a traffic light at an intersection further along the mass-transit vehicle's route.
17. The traffic-preemption system of claim 14 , wherein the controller is further adapted to generate the traffic-preemption command for a traffic light based on a preemption hierarchy.
18. A traffic-preemption system, comprising:
means for transmitting an identification code from a transmitter associated with the mass-transit vehicle;
means, for receiving the identification code at a receiver situated at the traffic location;
means for identifying the mass-transit vehicle using the identification code;
means for comparing a time of the mass-transit vehicle's arrival at the traffic location with a pre-determined schedule;
means for determining a variance between the time of arrival and the pre-determined schedule; and
means for generating a traffic-preemption command for a traffic light based on the determined variance.
19. The traffic-preemption system of claim 18 , wherein the generating means comprises means for determining if the variance exceeds a threshold.
20. The traffic-preemption system of claim 19 , wherein the generating means comprises means for determining a traffic-preemption command hierarchy.