Traffic data management and simulation system

• US 7,155,376 B2
• Filed: 06/24/2002
• Issued: 12/26/2006
• Est. Priority Date: 06/22/2001
• Status: Active Grant

• Current Assignee: Caliper Corporation
• Original Assignee: Caliper Corporation
• Inventors: Yang, Qi, Brandon, Jonathan, LaClair, Mary, Stefansson, Kjartan, Slavin, Howard, Olsberg, Simon, Rabinowicz, Andres
• Primary Examiner(s): Ohah, Kamini
• Assistant Examiner(s): LUU, CUONG V
• Application Number:
  US10/179,643
• Publication Number:
  US 20020198694A1
• Time in Patent Office: 1,646 Days
• Field of Search: 703/8, 703/6, 340988-996, 701/200, 701/201, 706/902, 706/913
• US Class Current: 703/8
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• CPC Class Codes: G08G 1/0112 from the vehicle, e.g. floating car data [FCD]
• CPC Class Codes: G08G 1/0129 for creating historical data or processing based on historical data
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

Systems and methods for, inter alia, geographically based analyses of traffic being carried over a wide scale traffic network. The systems integrate geographical information systems (GIS) with traffic simulation processes to allow a user to analyze traffic patterns and loads at specific geographic locations of regions. Additionally, these systems allow for traffic analysis over a wide scale traffic network that may encompass the traffic network that exists within an geographic region and can include, as examples, the traffic networks that span across a city, that interconnect cities, that interconnect states and that run across multiple states. To this end, the systems include traffic simulators that can adaptively or controllably select between multiple traffic simulation models for simulating traffic across different segments of the traffic network. The different models provide varying levels of granularity for measurements of geographical location of a vehicle traveling over the traffic network.

Claims

1. A system for analyzing traffic flow, comprising:

a GIS database having a geographically accurate lane-level network representation of a transportation environment;

a GIS database manager for allowing a user to form spatial queries representative of objects in said network, said GIS database being responsive to said CIS database manager for processing said spatial queries;

a traffic simulator for simulating, at an individual vehicle level, as a function of the network representation, a flow, across the transportation environment, of traffic comprising a plurality of individual vehicles; and

a database interface responsive to said traffic simulator for processing simulation data and for creating GIS data representative of time-varying traffic data and for modifying demand data stored in said GIS database.

2. A system according to claim 1, further comprising

an animator process for processing said network representation and said time varying traffic data to generate a visual animation of traffic flow across the transportation environment wherein:

the lane-level network and individual vehicle objects may be thematically represented with respect to values of traffic data attributes.

3. A system according to claim 1, further comprising an editor for editing the lane-level network representation to create a modified transportation environment.

4. A system according to claim 1, wherein the GIS database includes a network representation having information representative of geographical coordinates of the transportation environment.

5. A system according to claim 1, wherein the lane-level network representation includes a network formed of links, link segments, and nodes, lanes and intersections having accurate geographic shape and placement.

6. A system according to claim 1, further including storage for a segment/node attribute representative of a plurality of traffic simulation models to apply to a portion of the lane-level network representation for simulating movement of one or more vehicles.

7. A system according to claim 6, wherein:

the lane-level network representation includes a plurality of link segments connected at a plurality of nodes, said system having;

storage associated with at least one node for storing a segment/node attribute representative of which of said plurality of traffic simulation models to apply during a traffic simulation process to link segments coupled to the respective node.

8. A system according to claim 6, wherein the segment/node attribute may be representative of a microscopic, mesoscopic or macroscopic traffic simulation model.

9. A system according to claim 6, wherein:

the lane-level network representation includes links, link segments, nodes lanes and intersections having accurate geographic shape and placement; and

the segment/node attributes are associated with nodes occurring within the lane-level network representation.

10. A system according to claim 6, further including means for associating a segment of the network representation with a selected segment/node attribute.

11. A system according to claim 6, further including means for transitioning between traffic simulation models in response to a vehicle mapped on a first part of the lane-level network representation being mapped to a second part of the lane-level network representation.

12. A system according to claim 1, wherein the lane level network representation of the transportation environment includes storage for data representative of three dimensional world coordinates for accurate shape and elevation.

13. A system according to claim 12, further including a user interface that presents data in a graphical form that employs geographical data in the database to create a geographically accurate graphical representation of the traffic environment.

14. A system according to claim 1, wherein the traffic simulator includes means for simulating behavioral characteristics of drivers of individual vehicles.

15. A system according to claim 1, wherein the traffic simulator includes a route selector for selecting a route for a vehicle to travel to traverse from an origin to a destination.

27. The system according to claim 1 wherein the database interface is further responsive to said traffic simulator for modifying demand data stored in said GIS database.

28. The system according to claim 1 wherein said time-varying traffic data represents intervals of at most 10 seconds.

29. The system according to claim 28 wherein said time-varying traffic data represents intervals of between 5 seconds and 10 seconds.

30. The system according to claim 28 wherein said time-varying traffic data represents intervals of between 1 second and 2 seconds.

31. The system according to claim 28 wherein said time-varying traffic data represents intervals of 0.1 second.

42. A system according to claim 27, further comprising an editor for editing the demand data to create a modified simulation.

16. A process for analyzing traffic flow, comprising:

creating a GIS database having information representative of a geographically accurate lane level network representation of a transportation environment and demand data representative of traffic demands placed on the respective transportation environment,

providing a GIs database manager for applying spatial queries to said GIS database representative of object in said lane-level network representation, for identifying traffic demand at selected geographical coordinates; and

simulating, within a single simulation, as a function of (a) time, (b) the lane-level network representation, and (c) the traffic demand information, a flow, across the transportation environment, of traffic comprising a plurality of individual vehicles;

thereby;

creating GIS data representative of time varying traffic data, whereby spatial queries can be applied to the GIS database for performing a dynamic analysis of traffic flow.

17. A process according to claim 16, further comprising providing a segment/node attribute with the lane-level network representation to associate one of a plurality of traffic simulation models with at least a portion of the network representation.

18. A process according to claim 16, wherein:

the lane-level network representation includes links, link segments, nodes, lanes and intersections having accurate geographic shape and placement;

said process further comprising;

associating a segment/node attribute with a node occurring within the lane-level network representation.

19. A process according to claim 18, further comprising simulating movement of a vehicle across a link segment as a function of a segment/node attribute associated with a node to which the link segment connects.

20. A process according to claim 18, further comprising:

identifying a link that connects between two nodes having different segment/node attributes;

dividing the link into two separate segments, a first segment associated with one segment/node attribute and a second segment associated with another segment/node attribute;

wherein;

each segment is associated with a geographical location.

21. A process according to claim 20, further comprising:

monitoring the geographical location of a vehicle and determining when the simulating of a vehicle moves the vehicle from the first segment to the second segment; and

responding to the change in segment/node attribute by changing a traffic simulation model employed to simulate movement of the vehicle.

32. The process of claim 16 further comprising updating the traffic demand information within the GIS database.

33. The process of claim 16 wherein said time-varying traffic data represents intervals of at most 10 seconds.

34. The process of claim 33 wherein said time-varying traffic data represents intervals of between 5 seconds and 10 seconds.

35. The process of claim 33 wherein said time-varying traffic data represents intervals of between 1 second and 2 seconds.

36. The process of claim 33 wherein said time-varying traffic data represents intervals of 0.1 second.

22. A process for simulating traffic flow across a heterogeneous transportation environment, comprising:

creating a GIS database having information representative of a geographically accurate lane-level network representation of a transportation environment including at least two types of roadways and information representative of traffic demands placed on the respective transportation environment,

associating with a first type of roadways within the network representation a segment/node attribute representative of a traffic simulation models to apply during a traffic simulation process of vehicles moving across the first type of roadways and associating with a second type of roadways a different segment/node attribute to apply during a traffic simulation process of vehicles moving across the second type of roadways,

providing a GIS database manager for applying spatial queries to said GIS database representative of queries formed from at least one spatial characteristic, for identifying traffic demand at selected geographical coordinates,

simulating, within a single simulation, as a function of (a) time, (b) the network representation, (c) the traffic demand information, and (d) the segme/node attributes, a flow of traffic across the transportation environment,

determining when a vehicle from the first type of roadway to the second type of roadway and responding by changing which of said plurality of traffic simulation models is employed to simulate movement of the vehicle; and

updating traffic demand information within the GIS database for creating GIS data representative of time varying traffic data, whereby spatial queries can be applied to the GIS database for performing a dynamic analysis of traffic flow across a heterogeneous transportation environment.

37. The process of claim 22 wherein said time-varying traffic data represents intervals of at most 10 seconds.

38. The process of claim 37 wherein said time-varying traffic data represents intervals of between 5 seconds and 10 seconds.

39. The process of claim 38 wherein said time-varying traffic data represents intervals of between 1 second and 2 seconds.

40. The process of claim 38 wherein said time-varying traffic data represents intervals of 0.1 second.

23. A method of traffic simulation, comprising:

applying geographic characteristics to information representative of a transportation environment that encompasses a wide scale traffic network;

applying one of a plurality of traffic simulations at different levels of detail substantially simultaneously to each of a plurality of different portions of the transportation environment within a single simulation, to model traffic flows over a said wide scale traffic network; and

updating a database of traffic demand representative of vehicle-level traffic volume at geographic locations in the transportation environment.

24. A method according to claim 23 wherein traffic data includes information on intersections, road, lanes, traffic signals and signs, surveillance sensors, vehicles, transit, signal timings, historical travel times, and estimates of travel demand.

25. A method according to claim 24, further including providing a database manager for forming spatial queries of traffic network objects and data associated with them.

26. A method according to claim 24, further including joining external data tables of objects to which geographic characteristics have been applied to information, representative of a transportation environment, to which geographic characteristics have been applied.

41. A system for analyzing traffic flow, comprising:

a GIS database having a geographically accurate lane-level network representation of a transportation environment, said network representation including representations of a plurality of features; and

a traffic simulator for simulating a flow of traffic across said transportation environment as represented by said network representation; and

an interface for accepting input including selection criteria for selecting among said features;

wherein;

said traffic simulator simulates said flow of traffic to a first level of detail for a first subset of said at least some features of said network representation, and substantially simultaneously to at least one other level of detail different from said first level of detail for a second subset of said at least some features of said network representation within a single simulation; and

said first and second subsets are identified based at least in part on said input.

43. A traffic simulation system for simulating, at an individual vehicle level, a flow of traffic across a transportation network, said traffic simulation system comprising:

a plurality of traffic simulators, each of said traffic simulators being operable on any portion of said transportation network;

wherein;

any combination of at least two of said traffic simulators operates substantially simultaneously on different portions of said transportation network within a single simulation; and

at least a portion of said simulation operates at an individual vehicle level.

44. The traffic simulation system of claim 43 wherein said plurality of traffic simulators comprises a microscopic model, a mesoscopic model and a macroscopic model.

45. The traffic simulation system of claim 44 wherein:

said microscopic model comprises;

vehicle-following logic, and lane-changing logic; and

said microscopic model tracks vehicle location in detail.

46. The traffic simulation system of claim 45 wherein said microscopic model tracks vehicle location to geographic coordinates in a lane.

47. The traffic simulation system of claim 44 wherein:

said mesoscopic model operates on a speed density function; and

said mesoscopic model tracks vehicle location approximately.

48. The traffic simulation system of claim 47 wherein said microscopic model tracks vehicle location to geographic coordinates in a road segment.

49. The traffic simulation system of claim 44 wherein:

said macroscopic model operates on an aggregate delay function; and

said macroscopic model tracks vehicle entry times into one of (a) a link, and (b) a node.

50. The traffic simulation system of claim 43 further comprising:

a user interface for designating nodes and segments of said transportation network as being operated on by a one of said plurality of traffic simulation models;

whereby;

a user determines which simulation model operates on any portion of said transportation network.

51. The traffic simulation system of claim 43 wherein different time steps are used to simulate different ones of said portions of said transportation network.

52. The traffic simulator simulation system of claim 43 wherein said transportation network is represented by a geographically accurate lane-level representation of roadways, intersections and vehicle movements.

53. The traffic simulation system of claim 52 wherein said geographic representation comprises three-dimensional real-world geographic coordinates.

54. The traffic simulation system of claim 53 further comprising a geographic information system (GIS) to provide said geographically accurate lane-level representation.

55. The traffic simulation system of claim 53 wherein said geographically accurate lane-level representation in said GIS comprises representations of road segments and connections, lanes, lane widths, lane configurations and connections, traffic controls and elevations.

56. The traffic simulation system of claim 55 wherein said traffic controls are selected from the group consisting of traffic sensors, traffic signals and combinations thereof.

57. The traffic simulation system of claim 55 wherein said geographically accurate lane-level representation in said GIS further comprises control data for said traffic controls.

58. The traffic simulation system of claim 57 wherein said control data comprise timing data.

59. The traffic simulation system of claim 57 wherein said control data comprise settings data.

60. The traffic simulation system of claim 55 wherein said GIS further comprises representations of lane use privileges and turning regulations.

61. A geographic information system (GIS) comprising:

a geographic database comprising geographically accurate representations of road segments and connections, lanes, lane widths, lane configurations and connections, traffic controls and elevations; and

a database manager comprising an interface for querying said geographic database.

62. The GIS of claim 61 wherein said traffic controls are selected from the group consisting of traffic sensors, traffic signals and combinations thereof.

63. The GIS of claim 61 wherein said geographic representation in said GIS further comprises control data for said traffic controls.

64. The GIS of claim 63 wherein said control data comprise timing data.

65. The GIS of claim 63 wherein said control data comprise settings data.

66. The GIS of claim 61 wherein said geographic database further comprises representations of lane use privileges and turning regulations.

67. The GIS of claim 61 wherein said database manager includes a vehicle routing system.

68. The GIS of claim 67 wherein:

said geographic database further comprises representations of vehicle locations; and

said routing system routes vehicles accurately through intersections.

69. The GIS of claim 68 wherein said representations of vehicle locations are time-varying.

70. The GIS of claim 61 wherein said database manager interfaces with a traffic simulation.

71. The GIS of claim 70 wherein:

said geographic database further comprises representations of vehicle locations; and

said traffic simulation simulates the movements of vehicles accurately through intersections.

72. The GIS of claim 61 wherein said geographic database further comprises representations of vehicle locations.

73. The GIS of claim 72 wherein said vehicle locations are stored at lane level and at positions inside intersections.

74. The GIS of claim 73 wherein said vehicle locations are stored as geographic coordinates.

75. The GIS of claim 72 wherein said representations of vehicle locations are time-varying.

76. The GIS of claim 75 wherein said time-varying traffic data represents intervals of at most 10 seconds.

77. The GIS of claim 76 wherein said time-varying traffic data represents intervals of between 5 seconds and 10 seconds.

78. The GIS of claim 76 wherein said time-varying traffic data represents intervals of between 1 second and 2 seconds.

79. The GIS of claim 76 wherein said time-varying traffic data represents intervals of 0.1 second.