US-12620305-B2 - Method, system, computer program and computer readable medium for generating closure data relating to closure of a stretch of navigable elements

US12620305B2US 12620305 B2US12620305 B2US 12620305B2US-12620305-B2

Abstract

A method for generating data regarding closure of a stretch of navigable elements, includes: identifying source navigable elements and destination navigable elements in a region around the stretch; generating traffic flow indicators, each being based on a comparison of a reference measure and a closure measure. The reference measure indicates a number of first journeys relative to a number of second journeys during a reference period. The closure measure indicates a number of first journeys relative to a number of second journeys during a test period. Each first journey includes movement of a respective client from a respective source navigable element to a navigable element of the stretch and then to a respective destination navigable element. Each second journey includes movement of a respective client from a respective source navigable element to a respective destination navigable element without a stretch navigable element. The data is generated based on the indicators.

Inventors

Sören Sven Sonnenburg
Przemyslaw Polewski
Lucian Ionescu
Gijs Peters
Yucel Kenan Ozturk

Assignees

TOMTOM TRAFFIC B.V.

Dates

Publication Date: 20260505
Application Date: 20220427
Priority Date: 20210428

Claims (20)

1 . A method for generating closure data relating to closure of a stretch of navigable elements during a target time period, wherein the stretch comprises one or more navigable elements of a network of navigable elements within a geographic area, wherein the method includes: identifying a set of source navigable elements of the network and a set of destination navigable elements of the network in a region around the stretch; generating one or more traffic flow indicators for the stretch, each traffic flow indicator being for a respective test time period in a set of one or more test time periods within the target time period, each traffic flow indicator being based on a comparison of a respective reference traffic flow measure for the stretch and a respective closure traffic flow measure for the stretch, wherein: (a) the reference traffic flow measure is indicative of a number of first journeys during a reference time period for the test time period relative to a number of second journeys during the reference time period, and (b) the closure traffic flow measure is indicative of a number of first journeys during the test time period relative to a number of second journeys during the test time period, wherein each first journey includes movement of a respective client from a respective source navigable element to at least one navigable element of the stretch and then to a respective destination navigable element, and each second journey includes movement of a respective client from the respective source navigable element to the respective destination navigable element without a navigable element of the stretch between the source navigable element and the destination navigable element; and generating the closure data based on the one or more traffic flow indicators.
2 . The method of claim 1 , wherein the closure data comprises an indication of whether, during the target time period, the stretch had a closure.
3 . The method of claim 2 , wherein a first test time period in the set of one or more test time periods is the target time period, and the indication of whether, during the target time period, the stretch had a closure is generated according to the traffic flow indicator for the first test time period.
4 . The method of claim 2 , wherein one of the following applies: (a) the reference time period for the first test time period is for the same time as the target time period but on a day preceding the day of the target time period; (b) the reference time period for the first test time period is for the same time as the target time period but on the day immediately preceding the day of the target time period; (c) the reference time period for the first test time period is for the same time as the target time period but on a day that is the same weekday as, and that precedes, the day of the target time period; (d) the reference time period for the first test time period is a period of time immediately preceding the target time period.
5 . The method of claim 2 , wherein the reference time period for the first test time period is a period of time for which it is known or is assumed that the stretch did not have a closure.
6 . The method of claim 5 , comprising: (a) determining that the stretch had a closure during the target time period if the traffic flow indicator for the first test time period indicates that the reference traffic flow measure for the first test time period differs from the closure traffic flow measure for the first test time period by at least a first threshold; or (b) determining that the stretch did not have a closure during the target time period if the traffic flow indicator for the first test time period indicates that the reference traffic flow measure for the first test time period does not differ from the closure traffic flow measure for the first test time period by at least the first threshold.
7 . The method of claim 5 , comprising: (a) determining that the stretch had a closure during the target time period if the traffic flow indicator for the first test time period corresponds to an increase, above a second threshold, of the number of second journeys relative to the number of first journeys compared to the number of second journeys relative to the number of first journeys for the reference time period; or (b) determining that the stretch did not have a closure during the target time period if the traffic flow indicator for the first test time period does not correspond to an increase, above the second threshold, of the number of second journeys relative to the number of first journeys compared to the number of second journeys relative to the number of first journeys for the reference time period.
8 . The method of claim 1 , wherein the closure data comprises a time indication, the time indication being an indication of a time at which the stretch closed and/or an indication of a time at which the stretch reopened.
9 . The method of claim 8 , comprising generating, for each test time period in a sequence of successive test time periods within the target time period, a corresponding traffic flow indicator, wherein the time indication is determined based on changes between traffic flow indicators for successive test time periods in the sequence of test time periods.
10 . The method of claim 9 , wherein the time at which the stretch closed and/or the time at which the stretch reopened is determined according to successive test time periods for which there is a maximal magnitude of change between their traffic flow indicators.
11 . The method of claim 10 , wherein either: (a) the time at which the stretch closed is determined according to successive test time periods for which there is a maximal increase between their traffic flow indicators and the time at which the stretch reopened is determined according to successive test time periods for which there is a maximal decrease between their traffic flow indicators; or (b) the time at which the stretch closed is determined according to successive test time periods for which there is a maximal decrease between their traffic flow indicators and the time at which the stretch reopened is determined according to successive test time periods for which there is a maximal increase between their traffic flow indicators.
12 . The method of claim 9 , wherein either: (a) all of the test time periods in the sequence of successive test time periods have the same reference time period; or (b) for each of the test time periods in the sequence of successive test time periods except for the first test time period in the sequence of successive test time periods, the reference time period for that test time period is the immediately preceding test time period in the sequence of successive test time periods.
13 . The method of claim 1 , comprising maintaining a database of traces, wherein each trace represents a journey of a respective client in the geographic area, wherein the first journeys and the second journeys are journeys, or parts thereof, represented by traces in the database.
14 . The method of claim 1 , wherein the closure data is generated for one or more types of vehicle, wherein the first journeys and the second journeys are journeys for clients of vehicles of the one or more types of vehicle.
15 . The method of claim 1 , wherein the set of source navigable elements and the set of destination navigable elements are identified based, at least in part, on the stretch.
16 . The method of claim 15 , wherein identifying the set of source navigable elements and the set of destination navigable elements comprises identifying one or more predetermined navigable elements that are associated, in a database, with at least one navigable element of the stretch.
17 . The method of claim 15 , wherein the set of source navigable elements and the set of destination navigable elements are identified based, at least in part, on the reference time period.
18 . The method of claim 15 , wherein the set of source navigable elements and the set of destination navigable elements are identified based, at least in part, on being a target distance from the stretch.
19 . The method of claim 18 , wherein the target distance comprises: (a) a distance, or a range of distances, within the geographic area; (b) a number, or a range of numbers, of navigable elements.
20 . The method of claim 15 , comprising determining the region around the stretch, wherein identifying the set of source navigable elements and the set of destination navigable elements comprises identifying one or more navigable elements that intersect a boundary of the region around the stretch.

Description

TECHNICAL FIELD The present invention relates to methods, systems and computer programs for generating closure data relating to closure of a stretch of navigable elements. BACKGROUND OF THE INVENTION Vehicles (such as cars, motorbikes, lorries, etc.) usually travel along “navigable elements” of a network of navigable elements. The “navigable element” may be a road, or a portion/section of a road, within a road network. It will be appreciated, though, that other types of “navigable element” exist, e.g. routes, or parts thereof, taken by ferries or trains; paths, or parts thereof, for pedestrians; cycle paths or parts thereof; etc. Thus, a navigable element may be viewed as a part of a transport network along which travel may be conducted, e.g. by a vehicle, a person, etc. Sometimes, a navigable element may be closed (i.e. have, or experience, a closure). This may take many forms—e.g. the navigable element may be closed to all vehicles or to some types of vehicle; the navigable element may be closed in one or more directions; all parts of the navigable element may be closed, or only a subset of parts of the navigable element (e.g. certain lanes of a road) may be closed. Closures can happen for a variety of reasons, e.g. so that maintenance/building work on the navigable element can take place; so that other maintenance/building work (e.g. for a utility service) in the vicinity of the navigable element can take place; due to an accident, such as a car crash; due to hazardous environmental conditions (e.g. flooding); etc. The duration of closures can vary significantly from one closure to the next, depending on the specific circumstances surrounding the closures. Methods for obtaining information about a closure of a navigable element are well-known. For example: (a) WO2014/147200 describes a method to detect closures based on location data. The method detects when there is a change in the traffic distribution in the network. Imbalance in the inflow of traffic may signal the end of a closed navigable element. Imbalance at the outflow of traffic may signal the start of a closed navigable element.(b) WO2015/050348 describes a method of detecting the closure of a navigable element forming part of a network of navigable elements within a geographic area. It uses positional data to determine an elapsed time since a device was last detected on the navigable element, and the determined elapsed time is compared to an expected time interval between consecutive devices being detected on the navigable element. The navigable element is identified as being potentially closed, subject to one or more optional validation steps, when the determined elapsed time exceeds the expected time interval, e.g. by a predetermined amount.(c) WO2015/173252 describes a method of identifying navigable stretches that are partially closed. A server obtains positional data relating to the movement of a plurality of devices along a navigable stretch with respect to time in a given time period, wherein the time period is a period of non-congested traffic flow. The positional data is used to determine an average speed of travel along the navigable stretch in the given time period. The determined average speed of travel is compared to a free flow speed for the navigable stretch, and the navigable stretch is identified as being partially closed when the determined average speed of travel is lower than the free flow speed by a predetermined value.(d) WO2017/009466 and WO2017/009464 describe methods to detect the closure and opening (respectively) of a navigable element. The methods involve assigning a passability function and adjusting the function based on location data and on a report from an external source.(e) WO2017/037155 describes a method for detecting that a previously closed navigable element is open when location data over a time interval exceeds a threshold value determined based on location data for an earlier time period. Often, the information on closures (particularly road closures) is determined by processing so-called “probe data” provided by navigation clients (e.g. clients in, or executed by, vehicles travelling on the network; clients carried by pedestrians, such as mobile phone apps; etc.). Additionally, information on closures may be obtained from third parties (e.g. when a road management entity plans a closure to occur at some point in the future). Reliable information on closures strives to avoid false negatives (missed closures) and false positives (reporting non-closed navigable elements as being closed). This is often challenging, at least in part due to the wide range of scenarios in which closures can take place (the reasons for the closure, the configuration of navigable elements in the vicinity of the closure, the type of closure, etc.). Detecting closures is further complicated as even for closed navigable elements, some types of traffic (e.g. motorcycles, bicycles, pedestrians, emergency vehicles) may still be able