Determination of a free-flow speed for a link segment

Patent metadata

Field	Value
Publication number	US-9761133-B2
Application number	US-201514751682-A
Country	US
Kind code	B2
Filing date	Jun 26, 2015
Priority date	Jun 26, 2015
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A method comprising determining speed-time cluster application histogram data set for a link segment that comprises a plurality of speed-time cluster application histogram data elements, each speed-time cluster application histogram data element identifying a speed-time cluster and an applicable duration of the speed-time cluster for the link segment throughout a histogram duration, for each speed-time cluster application histogram data element, determining a free-flow speed that is representative of a non-congestion speed indicated by the speed-time cluster, determining a historically normalized free-flow speed for the link segment that is a weighted average of the free-flow speed determined for each speed-time cluster application histogram data element weighted by the applicable duration of the speed-time cluster application histogram data element, and identifying a transit speed of the link segment as being the historically normalized free-flow speed is disclosed.

First claim

What is claimed is:

1. An apparatus, comprising:
at least one processor;
at least one memory including computer program code, the memory and the computer program code configured to, working with the processor, cause the apparatus to perform at least the following:
receiving probe data collected by one or more sensors;
determining, from the probe data, a speed-time cluster application histogram data set for a link segment that comprises a plurality of speed-time cluster application histogram data elements, each speed-time cluster application histogram data element identifying a speed-time cluster and an applicable duration of the speed-time cluster for the link segment throughout a histogram duration;
for each speed-time cluster application histogram data element, determining a free-flow speed that is representative of a non-congestion speed indicated by the speed-time cluster;
calculating, by a processor, a historically normalized free-flow speed for the link segment that is a weighted average of the free-flow speed determined for each speed-time cluster application histogram data element weighted by the applicable duration of the speed-time cluster application histogram data element;
calculating, by the processor, a predicted transit speed of the link segment as being the historically normalized free-flow speed; and
providing the predicted transit speed to a map or a navigation system.

2. The apparatus of claim 1 , wherein a link segment is at least a portion of at least one of a route, a lane, a road, a highway, a street, a trail, or a thoroughfare.

3. The apparatus of claim 1 , wherein the determining the speed-time cluster application histogram data set comprises:
receiving probe data indicative of speed of travel along the link segment;
identifying an applicable speed-time cluster associated with the link segment that is applicable to the probe data;
determining an applicable duration throughout the histogram duration in which the applicable speed-time cluster is applicable to the probe data; and
determining a speed-time cluster application histogram data element of the speed-time cluster application histogram data set that indicates the applicable speed-time cluster and the applicable duration.

4. The apparatus of claim 1 , wherein the determining the free-flow speed comprises:
identifying of portions of the speed-time cluster that are indicative of non-congestion; and
determining the free-flow speed based on a speed indicated by the identified portions of the speed-time cluster that are indicative of non-congestion.

5. The apparatus of claim 4 , wherein the determining the free-flow speed based on the speed indicated by the identified portions of the speed-time cluster omits portions of the speed-time cluster that are indicative of congestion.

6. The apparatus of claim 4 , wherein the determining the free-flow speed based on the speed indicated by the identified portions of the speed-time cluster comprises determining the free-flow speed based on a maximum speed indicated by the identified portions of the speed-time cluster that are indicative of non-congestion.

7. The apparatus of claim 4 , wherein the determining the free-flow speed based on the speed indicated by the identified portions of the speed-time cluster comprises determining the free-flow speed based on a percentage of a maximum speed indicated by the identified portions of the speed-time cluster that are indicative of non-congestion.

8. The apparatus of claim 7 , wherein the percentage is between 80 percent and 90 percent.

9. The apparatus of claim 1 , wherein the memory includes computer program code configured to, working with the processor, cause the apparatus to perform:
determining that the link segment is geospatially associated with a set of link segments; and
identifying a transit speed of the set of link segments as being the historically normalized free-flow speed.

10. A method comprising:
determining speed-time cluster application histogram data set for a link segment that comprises a plurality of speed-time cluster application histogram data elements, each speed-time cluster application histogram data element identifying a speed-time cluster and an applicable duration of the speed-time cluster for the link segment throughout a histogram duration;
for each speed-time cluster application histogram data element, determining a free-flow speed that is representative of a non-congestion speed indicated by the speed-time cluster;
determining a historically normalized free-flow speed for the link segment that is a weighted average of the free-flow speed determined for each speed-time cluster application histogram data element weighted by the applicable duration of the speed-time cluster application histogram data element;
calculating a predicted transit speed of the link segment as being the historically normalized free-flow speed; and
providing the predicted transit speed to a map or a navigation system.

11. The method of claim 10 , wherein the determining the speed-time cluster application histogram data set comprises:
receiving probe data indicative of speed of travel along the link segment;
identifying an applicable speed-time cluster associated with the link segment that is applicable to the probe data;
determining an applicable duration throughout the histogram duration in which the applicable speed-time cluster is applicable to the probe data; and
determining a speed-time cluster application histogram data element of the speed-time cluster application histogram data set that indicates the applicable speed-time cluster and the applicable duration.

12. The method of claim 10 , wherein the determining the free-flow speed comprises:
identifying portions of the speed-time cluster that are indicative of non-congestion;
and determining the free-flow speed based on a speed indicated by the identified portions of the speed-time cluster that are indicative of non-congestion.

13. The method of claim 12 , wherein the determining the free-flow speed based on the speed indicated by the identified portions of the speed-time cluster omits portions of the speed-time cluster that are indicative of congestion.

14. The method of claim 12 , wherein the determining the free-flow speed based on the speed indicated by the identified portions of the speed-time cluster comprises determining the free-flow speed based on a maximum speed indicated by the identified portions of the speed-time cluster that are indicative of non-congestion.

15. The method of claim 12 , wherein the determining the free-flow speed based on the speed indicated by the identified portions of the speed-time cluster comprises determining the free-flow speed based on a percentage of a maximum speed indicated by the identified portions of the speed-time cluster that are indicative of non-congestion.

16. The method of claim 10 , further comprising:
determining that the link segment is geospatially associated with a set of link segments; and
identifying a transit speed of the set of link segments as being the historically normalized free-flow speed.

17. At least one non-transitory computer-readable medium encoded with instructions that, when executed by a processor, perform:
determining a speed-time cluster application histogram data set for a link segment that comprises a plurality of speed-time cluster application histogram data elements, each speed-time cluster application histogram data element identifying a speed-time cluster and an applicable duration of the speed-time cluster for the link segment throughout a his

Assignees

• Here Global Bv

Inventors

• Macfarlane Jane

Classifications

• G08G1/0129 Primary

  for creating historical data or processing based on historical data · CPC title

• G08G1/0112

  from the vehicle, e.g. floating car data [FCD] · CPC title

• G08G1/0141

  for traffic information dissemination · CPC title

• G08G1/0133

  for classifying traffic situation · CPC title