Traffic monitoring system and method

• US 10,557,714 B2
• Filed: 03/20/2015
• Issued: 02/11/2020
• Est. Priority Date: 10/10/2005
• Status: Active Grant

• Current Assignee: TomTom Traffic B.V. (TomTom NV)
• Original Assignee: TomTom Traffic B.V. (TomTom NV)
• Inventors: Adam, Thomas Bruce Watson, Atkinson, Ian Malcolm, Dixon, Michael Joseph
• Primary Examiner(s): Holwerda, Stephen
• Application Number:
  US14/664,150
• Publication Number:
  US 20150192422A1
• Time in Patent Office: 1,789 Days
• Field of Search: 701117, 701118, 701119, 701420, 701423, 701424, 701430, 701450, 701465, 701532, 701533, 701540
• CPC Class Codes: G01C 21/3492 employing speed data or traffic data, e.g. real-time or historical traffic control systems for road vehicles involving transmission of navigation instructions to the vehicle G08G1/0968
• CPC Class Codes: G08G 1/00 Traffic control systems for road vehicles arrangement of road signs or traffic signals E01F9/00 ; automatic vehicle control B62D
• CPC Class Codes: G08G 1/096827 where the route is computed onboard
• CPC Class Codes: G08G 1/096844 where the complete route is dynamically recomputed based on new data
• CPC Class Codes: G08G 1/096883 where input information is obtained using a mobile device, e.g. a mobile phone, a PDA
• CPC Class Codes: G08G 1/0969 having a display in the form of a map

Abstract

The present invention combines the geographical coverage possible with fixed, pre-defined route segment costs (e.g. the legal speed limit) with, wherever possible, richer time dependent costs. A user of, for example, a portable navigation device, can therefore continue route planning as before to virtually any destination in a country covered by the stored map database, but wherever possible, can also use traffic data with time-dependent costs, so that the effect of congestion with any time predictability can be accurately taken into account as an automatic, background process. It leaves the user to simply carry on driving, following the guidance offered by the navigation device, without needing to be concerned about congestion that exists now, and whether it will impact his journey.

Claims

1. A traffic monitoring system comprising a processing module arranged to process data representative of vehicles moving along roads in a designated geographical area, the roads being defined in a map database in a memory in terms of route segments, to measure traffic speed or transit time data as a function of time and to:

generate a database of historical time-dependent traffic speeds or transit times for at least some route segments in the map database, the data associated with a route segment comprising an average traffic speed or transit time along the route segment for each of a plurality of time windows;

identify currently congested route segments on which the traffic speed at a current time or transit time is less than expected;

predict a traffic speed or transit time for a requested future time for at least one currently congested route segment;

determine a current traffic speed ratio as a ratio of;

traffic speeds or transit times observed at a recent time, and

a predicted traffic speed or transit time at the recent time, the predicted traffic speed being a historical average traffic speed or transit time for the recent time;

scale the predicted traffic speed or transit time for the requested future time for the at least one currently congested route in proportion to the current traffic speed ratio, wherein said scaling comprises decaying the scaling as the distance of the prediction into the future grows; and

provide the predicted traffic speed or transit time to a navigation system for the requested future time.

2. The traffic monitoring system of claim 1 in which the data representative of vehicles moving along roads in a designated geographical area is derived from global positioning system (GPS) tracks stored by GPS based navigation devices in vehicles travelling along the roads.

3. A computer-implemented method in which data representative of vehicles moving along roads in a designated geographical area, the roads being defined in a map database in a memory in terms of route segments, is processed by a processing module of a traffic monitoring system to measure traffic speed or transit time data as a function of time, the method comprising:

generating a database of historical time-dependent traffic speeds or transit times for at least some route segments in the map database, the data associated with a route segment comprising an average traffic speed or transit time along the route segment for each of a plurality of time windows;

identifying currently congested route segments on which the traffic speed or transit time is less than expected at a current time;

predicting a traffic speed or transit time for a requested future time for at least one currently congested route segment;

determining a current traffic speed ratio as a ratio of;

traffic speeds or transit times observed at a recent time, and

a predicted traffic speed or transit time at the recent time, the predicted traffic speed being a historical average traffic speed or transit time for the recent time;

scaling the predicted traffic speed or transit time for the requested future time for the at least one currently congested route in proportion to the current traffic speed ratio, wherein said scaling comprises decaying the scaling as the distance of the prediction into the future grows; and

providing the predicted traffic speed or transit time to a navigation system for the requested future time.

4. The method of claim 3 in which the data representative of vehicles moving along roads in a designated geographical area is derived from global positioning system (GPS) tracks stored by GPS based navigation devices in vehicles travelling along the roads.

5. A non-transitory computer-readable medium which stores a set of instructions which when executed performs a method in which data representative of vehicles moving along roads in a designated geographical area the roads being defined in a map database in a memory in terms of route segments, is processed by a processing module of a traffic monitoring system to measure traffic speed or transit time data as a function of time, the method executed by the set of instructions comprising:

generating a database of historical time-dependent traffic speeds or transit times for at least some route segments in the map database, the data associated with a route segment comprising an average traffic speed or transit time along the route segment for each of a plurality of time windows;

identifying currently congested route segments on which the current traffic speed or transit time is less than expected;

predicting a traffic speed or transit time for a requested future time for at least one currently congested route segment;

determining a current traffic speed ratio as a ratio of;

traffic speeds or transit times observed at a recent time, and

a predicted traffic speed or transit time at the recent time, the predicted traffic speed being a historical average traffic speed or transit time for the recent time;

scaling the predicted traffic speed or transit time for the requested future time for the at least one currently congested route in proportion to the current traffic speed ratio, wherein said scaling comprises decaying the scaling as the distance of the prediction into the future grows; and

providing the predicted traffic speed or transit time to a navigation system for the requested future time.

6. The computer-readable medium of claim 5 in which the data representative of vehicles moving along roads in a designated geographical area is derived from global positioning system (GPS) tracks stored by GPS based navigation devices in vehicles travelling along the roads.