RFID intelligent traffic signaling

• US 8,035,530 B2
• Filed: 06/01/2009
• Issued: 10/11/2011
• Est. Priority Date: 11/09/2006
• Status: Active Grant

• Current Assignee: Sridhara Subbiah Ramasubbu
• Original Assignee: Sridhara Subbiah Ramasubbu
• Inventors: Ramasubbu, Sridhara Subbiah
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US12/475,705
• Publication Number:
  US 20090231160A1
• Time in Patent Office: 862 Days
• Field of Search: 340/916, 340/917, 340/922, 340/933, 340/941, 340/572.1, 340/572.4, 340/572.8
• US Class Current: 340/922
• CPC Class Codes: G08G 1/07 Controlling traffic signals
• CPC Class Codes: G08G 1/095 Traffic lights

Abstract

A system and method for regulating the flow of traffic at a roadway intersection having one or more traffic signals by positioning a processor in the vicinity of the intersection to store cycle times of the traffic flow directions, mounting an RFID reader in the vicinity of each traffic signal in communication with the processor, interrogating with the RFID reader an RFID tag on each RFID-tagged vehicle at the roadway intersection to count the number of RFID-tagged vehicles present in each traffic flow direction at the roadway intersection, calculating an unused time slice of the cycle time for a first traffic flow direction at the intersection; reducing the cycle time for the first traffic flow direction in accordance with the unused time slice; and, increasing the cycle time for a second traffic flow direction at the intersection in accordance with the unused time slice.

Claims

1. A method for regulating traffic flow of a plurality of vehicles at a roadway intersection, each vehicle in the plurality of vehicles comprising an RFID tag, the method comprising the steps of:

positioning a processor in the vicinity of the roadway intersection, said roadway intersection comprising a traffic signal that cycles vehicle flow in a plurality of traffic flow directions through the roadway intersection;

storing adaptable cycle times for the traffic signal in the processor;

mounting an RFID reader in the vicinity of the traffic signal, wherein the RFID reader is configured to communicate with the processor;

interrogating with the RFID reader an RFID tag on each vehicle in the plurality of vehicles to count the number of RFID tags present in each traffic flow direction at the roadway intersection;

calculating an unused time slice of the cycle time for a first traffic flow direction at the roadway intersection;

reducing the cycle time for the first traffic flow direction in accordance with the unused time slice; and

,

increasing the cycle time for a second traffic flow direction at the roadway intersection in accordance with the unused time slice.

2. A method as recited in claim 1, further comprising the steps of:

receiving priority data from an RFID tag mounted to a vehicle for which a right of way through the roadway intersection is to be granted; and

, processing the priority data to control the traffic signal in order to grant the right of way.

3. A method as recited in claim 1, wherein increasing the cycle time for the second traffic flow direction is further in accordance with a calculated demand for the unused time slice.

4. A method as recited in claim 1, further comprising the step of selecting the second traffic flow direction based on a calculation of the direction expected to have the greatest demand.

5. A method as recited in claim 1, further comprising the step of configuring the processor to send data to, and receive data from, a processor at another roadway intersection.

6. A method as recited in claim 1, wherein each traffic signal comprises a green, yellow and red light and the cycle times for the traffic signal include the duration of the green, yellow and red light during a given cycle;

and, wherein the unused time slice corresponds to at least a portion of the green light duration in a given traffic flow direction.

7. A method as recited in claim 1, wherein the RFID tag is affixed to a license plate of the vehicle.

8. A system for regulating the flow of vehicles at a roadway intersection, comprising:

a processor positioned in the vicinity of the roadway intersection, said roadway intersection comprising a traffic signal that cycles traffic flow in a plurality of traffic flow directions through the roadway intersection, wherein the processor is configured to store adaptable cycle times for the traffic signal;

an RFID reader mounted in the vicinity of the traffic signal, wherein the RFID reader is configured to communicate with the processor; and

,

an RFID tag mounted on each vehicle configured to be interrogated by the RFID reader when at the roadway intersection, the RFID tag thereby sending data to the RFID reader;

wherein the processor, in response to data received by the RFID reader from each RFID tag interrogated by the RFID reader, is further configured to;

count the number of RFID-tagged vehicles present in all of the traffic flow directions at the roadway intersection;

calculate an unused time slice of the cycle time for a first traffic flow direction at the roadway intersection;

reduce the cycle time for the first traffic flow direction in accordance with the unused time slice; and

,

increase the cycle time for a second traffic flow direction at the roadway intersection in accordance with the unused time slice.