Optimizing traffic speeds to minimize traffic pulses in an intelligent traffic system

• US 8,730,059 B2
• Filed: 11/24/2009
• Issued: 05/20/2014
• Est. Priority Date: 11/24/2009
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: McGinley, Robert C., Davis, William S.
• Primary Examiner(s): Lim, Steven
• Assistant Examiner(s): Adnan, Muhammad
• Application Number:
  US12/624,538
• Publication Number:
  US 20110121993A1
• Time in Patent Office: 1,638 Days
• Field of Search: 340907-9321
• US Class Current: 340/911
• CPC Class Codes: G08G 1/07 Controlling traffic signals

Abstract

According to a method of vehicular traffic management, a computer system receives, from devices distributed in a plurality of roadway segments of a physical roadway system, real-time traffic information individually describing vehicular traffic in each the plurality of roadway segments. The computer system determines from the real-time traffic information an advised speed for a particular roadway segment among the plurality of roadway segments. The computer system transmits, via a communication network, a speed advisory command specifying the advised speed to a device in the particular roadway segment for presentation.

Claims

1. A method of vehicular traffic management, comprising:

a computer system receiving, form devices distributed in a plurality of roadway segments of a physical roadway system including multiple intersecting roadways, real-time traffic information individually describing vehicular traffic in each of the plurality of roadway segments;

prior to the receiving, simulating traffic flow in the physical roadway system under a variety of traffic and weather conditions utilizing a simulation model of the physical roadway system and storing simulation results obtained by the simulating, wherein the simulation results include interrelationships of traffic speeds and volumes between roadway segments disposed in different ones of the multiple intersecting roadways;

the computer system determining from the real-time traffic information and the stored simulation results an advised speed for a particular roadway segment in a particular roadway among the multiple intersecting roadways, wherein the determining includes determining the advised speed for the particular roadway segment based on real-time traffic information from at least one other roadway segment in another of the multiple intersecting roadways and the interrelationships from the simulation results;

the computer system modifying a vehicle occupancy requirement of a high occupancy vehicle (HOV) lane spanning one or more of the plurality of roadway segments based on the real-time traffic information and the stored simulation results; and

the computer system transmitting, via a communication network, a speed advisory command specifying the advised speed to a device in the particular roadway segment for presentation.

2. The method of claim 1, wherein said determining comprises determining the advised speed based upon the real-time traffic information and real-time weather information for the particular segment.

3. The method of claim 1, wherein said transmitting comprises transmitting the speed advisory command to a variable speed advisory sign in the particular roadway segment.

4. The method of claim 1, wherein said transmitting comprises transmitting the speed advisory command to a vehicle in the particular roadway segment.

5. The method of claim 4, and further comprising:

in response to the speed advisory command, a vehicle computer in the vehicle controlling one or more systems of the vehicle to cause the vehicle to approach the advised speed.

6. The method of claim 1, wherein:

the method further comprises;

prior to the receiving, recording historical traffic information observed in the physical roadway system; and

determining the advised speed for the particular roadway segment comprises determining the advised speed from the real-time traffic information, the stored simulation results, and the recorded historical traffic information.

7. The method of claim 1, wherein:

the method further comprises defining a travel distance schema to be applied during simulation to simulated traffic in the simulation model, wherein the travel distance schema specifies minimum safe travel distances between vehicles for a plurality of traffic conditions; and

simulating traffic flow includes applying the travel distance schema to simulation traffic in the simulation model.

8. The method of claim 1, wherein:

the real-time traffic information includes identifying a plurality of different vehicle types within the vehicular traffic; and

determining the advised speed for the particular roadway segment comprises determining the advised speed based at least in part on the plurality of different vehicle types within the vehicular traffic.

9. The method of claim 1, wherein the determining comprises determining the advised speed for the particular roadway segment from real-time traffic information in another upstream roadway segment among the plurality of roadway segments.

10. The method of claim 1, wherein:

the real-time traffic information for each of the plurality of roadway segments includes a rate of change of vehicles transitioning between that roadway segment and an adjacent roadway segment; and

determining the advised speed for the particular roadway segment comprises determining the advised speed based at least in part on the rates of change of vehicles transitioning between roadway segments among the plurality of roadway segments.

11. The method of claim 1, wherein:

the method further comprises defining a travel distance schema to be applied during simulation to simulated traffic in the simulation model, wherein the travel distance schema specifies minimum safe travel distances between vehicles for a plurality of traffic conditions;

simulating traffic flow includes applying the travel distance schema to simulation traffic in the simulation model;

the method further comprises;

prior to the receiving, recording historical traffic information observed in the physical roadway system;

determining the advised speed for the particular roadway segment comprises determining the advised speed from the real-time traffic information, the stored simulation results, and the recorded historical traffic information;

the real-time traffic information includes identifying a plurality of different vehicle types within the vehicular traffic; and

determining the advised speed for the particular roadway segment comprises determining the advised speed based at least in part on the plurality of different vehicle types within the vehicular traffic.

12. The method of claim 1, and further comprising the computer system determining and controlling timing of traffic signal lights in the physical roadway system based on the real-time traffic information and the stored simulation results.

13. The method of claim 1, and further comprising the computer system modifying a number of available lanes in one or more of the plurality of roadway segments based on the real-time traffic information and the stored simulation results.

14. The method of claim 1, wherein determining the advised speed includes determining the advised speed based in part on the time of day.

15. The method of claim 1, and further comprising the computer system transmitting multiple additional speed advisory commands that sequentially modify advised speeds in immediately adjacent roadway segments upstream of the particular roadway segment until a desired real-time traffic metric is observed in the particular roadway segment.

16. The method of claim 15, wherein the desired real-time traffic metric is a traffic volume.

17. A program product for vehicular traffic management, the program product comprising:

a data storage device; and

program code stored within the data storage device, wherein the program code includes;

a simulator that when processed by a computer system causes the computer system to simulate traffic flow in a physical roadway system including multiple intersecting roadways under a variety of traffic and weather conditions utilizing a simulation model of the physical roadway system and to store simulation results obtained by the simulating, wherein the simulation results include interrelationships of traffic speeds and volumes between roadway segments disposed in different ones of the multiple intersecting roadways;

a roadway system manager that, when processed by the computer system, causes the computer system to;

receive, from devices distributed in a plurality of roadway segments of the physical roadway system, real-time traffic information individually describing vehicular traffic in each of the plurality of roadway segments;

determine from the real-time traffic information and the stored simulation results an advised speed for a particular roadway segment in a particular roadway among the multiple intersecting roadways, wherein the advised speed for the particular roadway segment is determined based on real-time traffic information from at least one other roadway segment in another of the multiple intersecting roadways and the interrelationships form the simulation results;

modify a vehicle occupancy requirement of a high occupancy vehicle (HOV) lane spanning one or more of the plurality of roadway segments based on the real-time traffic information and the stored simulation results; and

transmit, via a communication network, a speed advisory command specifying the advised speed to a device in the particular roadway segment for presentation.

18. The program product of claim 17, wherein program code causes the computer system to determine the advised speed based upon the real-time traffic information and real-time weather information for the particular segment.

19. The program product of claim 17, wherein program code causes the computer system to transmit the speed advisory command to a variable speed advisory sign in the particular roadway segment.

20. The program product of claim 17, wherein program code causes the computer system to transmit the speed advisory command to a vehicle in the particular roadway segment.

21. A data processing system for vehicular traffic management, the data processing system comprising:

a hardware processing unit;

a data storage medium coupled to the hardware processing unit; and

program code stored within the data storage medium, wherein the program code includes;

a simulator that when processed by the hardware processing unit causes the hardware processing unit to simulate traffic flow in the physical roadway system including multiple intersecting roadways under a variety of traffic and weather conditions utilizing a simulation model of the physical roadway system and to store simulation results obtained by the simulating, wherein the simulation results include interrelationships of traffic speeds and volumes between roadway segments disposed in different ones of the multiple intersecting roadways;

a roadway system manager that, when processed by the hardware processing unit, causes the hardware processing unit to;

receive, from devices distributed in a plurality of roadway segments of the physical roadway system, real-time traffic information individually describing vehicular traffic in each of the plurality of roadway segments;

determine from the real-time traffic information and the stored simulation results an advised speed for a particular roadway segment in a particular roadway among the multiple intersecting roadways, wherein the advised speed is determined for the particular roadway segment based on real-time traffic information from at least one other roadway segment in another of the multiple intersecting roadways and the interrelationships from the simulation results;

modify a vehicle occupancy requirement of a high occupancy vehicle (HOV) lane spanning one or more of the plurality of roadway segments based on the real-time traffic information and the stored simulation results; and

transmit, via a communication network, a speed advisory command specifying the advised speed to a device in the particular roadway segment for presentation.

22. The data processing system of claim 21, wherein program code causes the hardware processing unit to determine the advised speed based upon the real-time traffic information and real-time weather information for the particular segment.

23. The data processing system of claim 21, wherein program code causes the hardware processing unit to transmit the speed advisory command to a variable speed advisory sign in the particular roadway segment.

24. The data processing system of claim 21, wherein program code causes the hardware processing unit to transmit the speed advisory command to a vehicle in the particular roadway segment.