MEASURING TRAFFIC SPEED IN A ROAD NETWORK

• US 20170285181A1
• Filed: 08/26/2014
• Published: 10/05/2017
• Est. Priority Date: 08/26/2014
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Zheng, Yu, Chang, Eric
• Granted Patent: US 10,545,247 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 19/52 Determining velocity
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G08G 1/0112 from the vehicle, e.g. floating car data [FCD]
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons
• CPC Class Codes: G08G 1/012 from other sources than vehicle or roadside beacons, e.g. mobile networks
• CPC Class Codes: G08G 1/0129 for creating historical data or processing based on historical data
• CPC Class Codes: G08G 1/0133 for classifying traffic situation
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P
• CPC Class Codes: G08G 1/065 by counting the vehicles in a section of the road or in a parking area, i.e. comparing incoming count with outgoing count

Abstract

A computer system measures traffic speed on a road network. Sensors provide location data, over time, for a sampling of vehicles on the road network, such as a fleet of vehicles. This location data from a sampling of vehicles is sparse with respect to both road segments in the road network and time. From the location data, the computer system generates sample data associating speed of sampled vehicles on the road segments to points of time in a plurality of time slots. The computer system accesses other information that defines correlations among different road segments and among different time slots. The computer system derives at least an average vehicle speed for each road segment in the road network for at least the current time slot using the correlation data and the sparse sample data. The computer system can infer traffic volume from average vehicle speeds, and then compute environmental data.

Claims

1. A computer system for measuring traffic speed on road segments of a road network in a geographic area, comprising:

computer storage comprising;

sample data associating speed of sampled vehicles on road segments to points of time in a plurality of time slots, the sample data being derived from location data received from sensors that provide location data over time of the sampled vehicles;

correlation data defining correlations among road segments and correlations among time slots;

one or more processing units programmed to access the computer storage to process the sample data using the correlation data to provide an output describing, for each road segment in the road network, at least an average vehicle speed for each road segment in the road network for at least the current time slot.

2. The computer system of claim 1, wherein the output further comprises, for each road segment, an inferred traffic volume for each of the road segments for the current time slot.

3. The computer system of claim 2, wherein the output further comprises, for each road segment, environmental measures derived from at least the traffic volume for the road segments.

4. The computer system of claim 2, wherein the output further comprises, for each road segment, environmental measures derived from at least the average speed and the traffic volume for the road segments.

5. The computer system of claim 4, wherein traffic volume for each road segment is defined by a statistical model relating average speeds of the road segments and the road network information to the traffic volume.

6. The computer system of claim 1, wherein the output further comprises, for each road segment, environmental measures derived from at least the average speed for the road segments.

7. The computer system of claim 1, wherein the correlation data comprises;

road network information for each of the road segments and correlating the road segments; and

historic sample data including average speeds of sampled vehicles on the road segments in time slots prior to the current time slot.

8. The computer system of claim 7, wherein the road network information includes, for each road segment, a type of the road segment.

9. The computer system of claim 7,

wherein the road network information includes a matrix of road segments and features of the road segments;

wherein the historic sample information includes a matrix of time slots and average speeds for road segments in the time slots;

wherein the sample data includes a sparse matrix of time slots and speeds for the road segments in the time slots where sample vehicle traveled during the time slots; and

wherein processing includes factorizing the matrices to determine average speeds for other road segments where sample vehicles have not traveled in the current time slot.

10. The computer system of claim 1, wherein the sample data is received from sensors within the road network during a time slot.

11. The computer system of claim 10, wherein the sensors are on the sampled vehicles on the road segments.

12. The computer system of claim 10, wherein the sensors are on road segments in the road network.

13. The computer system of claim 1, wherein the processing of the sample data by the one or more processing units for a current time slot occurs in real time within a time slot of receiving the sample data.

14. A computer-implemented process comprising:

receiving sample data associating speed of sampled vehicles on road segments to points of time in a plurality of time slots, the sample data being derived from location data received from sensors that provide location data over time of the sampled vehicles;

accessing correlation data defining correlations among road segments and correlations among time slots; and

processing the sample data using the correlation data to provide an output describing, for each road segment in the road network, at least an average vehicle speed for each road segment in the road network for at least the current time slot.

15. An article of manufacture, comprising:

one or more computer storage media comprising at least one of a memory device and a storage device;

computer program instructions stored on the one or more computer storage media which, when processed by a computer, configure the computer to implement a process, comprising;

receiving sample data associating speed of sampled vehicles on road segments to points of time in a plurality of time slots, the sample data being derived from location data received from sensors that provide location data over time of the sampled vehicles;

accessing correlation data defining correlations among road segments and correlations among time slots; and

processing the sample data using the correlation data to provide an output describing, for each road segment in the road network, at least an average vehicle speed for each road segment in the road network for at least the current time slot.