# US 2025/0095481 A1 · Monitoring traffic

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- Number: US 2025/0095481 A1
- Document ID: US20250095481A1
- Status: Published application
- Kind: A1
- Application number: 18/713,128
- Filed: 2022-11-16
- Published: 2025-03-20
- Earliest claimed: 2021-11-26
- Assignees: Viavi Solution Inc.
- Applicants: Viavi Solution Inc.
- Inventors: Stuart LARGE
- Web page: https://patentgrep.com/patent/US20250095481A1

## CPC

- G08G 1/0133: {for classifying traffic situation}
- G01C 21/3691: {Retrieval, searching and output of information related to real-time traffic, weather, or environmental conditions (arrangements for giving variable traffic instructions G08G1/09)}
- G01H 9/004: {using fibre optic sensors (light guides per se G02B6/00, acousto-optical devices specially adapted for gating or modulating in optical wave guides G02F1/125)}
- G08G 1/0112: {from the vehicle, e.g. floating car data [FCD]}
- G08G 1/0145: {for active traffic flow control}
- G08G 1/015: with provision for distinguishing between two or more types of vehicles, e.g. between motor-cars and cycles
- G08G 1/02: using treadles built into the road (pads or other sensitive devices responsive to passage of vehicles E01F11/00)
- G08G 1/04: using optical or ultrasonic detectors
- G08G 1/052: with provision for determining speed or overspeed {(speed measuring in general G01P)}
- G08G 1/056: with provision for distinguishing direction of travel
- 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
- G01H 17/00: Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the other groups of this subclass
- G08G: TRAFFIC CONTROL SYSTEMS (guiding railway traffic, ensuring the safety of railway traffic B61L; arrangement of road signs or traffic signals E01F9/00; radar or analogous systems, sonar systems, lidar systems specially adapted for traffic control G01S13/91, G01S15/88, G01S17/88; {radar or analogous systems, sonar systems, lidar systems specially adapted for anti-collision purposes G01S13/93, G01S15/93, G01S17/93})
- G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S)
- G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES

## Abstract

There is described a method of estimating one or more properties of traffic passing along segments of a road network, the traffic comprising a plurality of vehicles. The method comprises receiving, from a radio navigation receiver located at each vehicle of a subset of the vehicles, one or more first properties of each of those vehicles. The method also comprises using distributed acoustic sensing to generate, as a function of time and of position along a subset of the segments of the road network, signals representing acoustic vibration caused by the traffic at one or more sensing optical fibres that extend along the subset of segments. The signals representing acoustic vibration caused by the traffic are then used to determine one or more second properties of the traffic in the subset of segments, and the received first properties of the vehicles in the subset of vehicles are combined with the determined second properties of the traffic in the subset of segments, to estimate one or more third properties of the traffic.

## Claims

### Claim 1

A method of estimating one or more properties of traffic passing along segments of a road network, the traffic comprising a plurality of vehicles, the method comprising:
receiving, from a radio navigation receiver located at each vehicle of a subset of said vehicles, one or more first properties of each of the vehicles in the subset of vehicles;
using distributed acoustic sensing to generate, as a function of time and of position along a subset of the segments of the road network, signals representing acoustic vibration caused by said traffic at one or more sensing optical fibres that extend along the subset of segments; using the signals representing acoustic vibration caused by said traffic to determine one or more second properties of said traffic in the subset of segments; and
combining the received first properties of the vehicles in the subset of vehicles with the determined second properties of the traffic in the subset of segments, to estimate one or more third properties of the traffic.

### Claim 2 (depends on 1)

The method of claim 1 wherein the one or more first properties of each of the vehicles in the subset of vehicles comprise one or more of: positions of said vehicles; positions of said vehicles to a spatial precision of worse than 5 metres or worse than 10 metres; directions of travel of said vehicles; and velocities or speeds of said vehicles.

### Claim 3 (depends on 1)

The method of claim 1 ex-wherein the one or more first properties of each of the vehicles in the subset of vehicles are sent by, or received from, each vehicle no more than every 10 seconds.

### Claim 4 (depends on 1)

The method of claim 1 wherein the one or more second properties of the traffic in the subset of segments comprise one or more of: a count or density of vehicles in the traffic; and a flow rate or velocity of the traffic.

### Claim 5 (depends on 1)

The method of claim 1 wherein the one or more second properties of the traffic in the subset of segments comprise one or more of: positions of particular vehicles; positions of particular vehicles to a spatial precision of better than 10 metres or of better than 5 metres; velocities of particular vehicles; and categories or sizes of particular vehicles.

### Claim 6 (depends on 1)

The method of claim 1 wherein the one or more second properties of the traffic in the subset of segments comprise one or more properties of queues of said traffic, wherein said one or more properties of queues of said traffic optionally comprise one or more of: the presence of a queue, the spatial positions of front and/or back boundaries
of a queue, the spatial length of a queue, and the time expected for a vehicle to remain in the queue.

### Claim 7 (depends on 1)

The method of claim 1 wherein the one or more second properties of said traffic in the subset of segments are determined more frequently than every 10 seconds.

### Claim 8 (depends on 1)

The method of claim 1 wherein the one or more third properties of the traffic comprise one or more of: an estimate of a proportion of the vehicles of the traffic within one or more particular segments of the segments subset, that are also within the vehicles subset; an estimate of the proportion of the vehicles of the vehicles subset, within one or more particular segments, that fall into each of two or more different categories or sizes of vehicles; and an estimate of the proportion of vehicles in each of two or more different categories, within one or more particular segments, that are found in the vehicles subset.

### Claim 9 (depends on 1)

The method claim 1 wherein the one or more third properties of the traffic are estimated from the one or more first properties with compensation using an estimate of a proportion of the vehicles of the traffic within one or more particular segments of the segments subset, that are also within the vehicles subset.

### Claim 10 (depends on 1)

The method of claim 1 wherein the one or more third properties of the traffic comprise one or more of: a count, density, flow rate or velocity of the traffic within one or more segments of the segments subset; a count, density, flow rate or velocity of the traffic in one or more segments outside the segments subset; an estimated journey time across the road network; an optimised vehicle route across the road network; and routes of particular vehicles.

### Claim 11 (depends on 1)

The method of claim 1 wherein by using the second properties, the one or more third properties of the traffic are estimated at a higher temporal and/or a higher spatial resolution than the corresponding temporal and/or spatial resolutions of the first properties.

### Claim 12 (depends on 11)

The method of claim 11 wherein by using the second properties, the one or more third properties define a particular lane of a roadway within which a particular vehicle is travelling.

### Claim 13 (depends on 11)

The method of claim 11 further comprising providing route guidance to a driver of a vehicle based on the one or more third properties of the traffic estimated at a higher temporal and/or a higher spatial resolution than the corresponding temporal and/or spatial resolutions of the first properties.

### Claim 14 (depends on 1)

The method of claim 1 wherein the one or more third properties of the traffic comprise one or more of: extended tracks of particular vehicles within the subset of segments; and extended tracks of particular vehicles which traverse segments both within and outside of the subset of segments.

### Claim 15 (depends on 14)

The method of claim 14 wherein each extended track for a particular vehicle comprises multiple track segments determined using the second properties, which are known to be associated to form an extended track of the particular vehicle by using the first properties.

### Claim 16

Apparatus for estimating one or more properties of traffic passing along segments of a road network, the traffic comprising a plurality of vehicles, the apparatus being arranged:
to receive, from a radio navigation receiver located at each vehicle of a subset of said vehicles, one or more first properties of each of the vehicles in the subset of vehicles;
to receive, from one or more distributed acoustic sensors each comprising one or more sensing optical fibres that extend along a subset of the segments of the road network, signals representing acoustic vibration caused by said traffic as a function of time and of position along the subset of segments;
to use the signals representing acoustic vibration caused by said traffic to determine one or more second properties of said traffic in the subset of segments; and
to combine the received first properties of the vehicles in the subset of vehicles with the determined second properties of the traffic in the subset of segments, to estimate one or more third properties of the traffic.

### Claim 17 (depends on 16)

The apparatus of claim 16 further comprising said one or more distributed acoustic sensors.

### Claim 18 (depends on 16)

The apparatus of claim 16 wherein the one or more first properties of each of the vehicles in the subset of vehicles comprise one or more of: positions of said vehicles;
positions of said vehicles to a spatial precision of worse than 5 metres or worse than 10 metres;
directions of travel of said vehicles; and velocities or speeds of said vehicles.

### Claim 19 (depends on 16)

The apparatus of claim 16 wherein the one or more second properties of the traffic in the subset of segments comprise one or more of: a count or density of vehicles in the traffic; a flow rate or velocity of the traffic; positions of particular vehicles; velocities of particular vehicles; categories or sizes of particular vehicles; and one or more properties of queues of said traffic, and
wherein the one or more third properties of the traffic comprise or more of an estimate of a proportion of the vehicles of the traffic within one or more particular segments of the segments ubset that are also within the vehicles subset, a count, density, flow rate or velocity of the traffic within one or more segments of the segments subset; a count, density, flow rate of velocity of the traffic in one or more s outside the segments subset; an estimated journey time across the road network; an optimised vehicle route across the road network; and routes of particular vehicles.

### Claim 20

canceled

### Claim 21 (depends on 16)

The apparatus of claim 16 further comprising one or more of:
a traffic signal control system arranged to receive said estimated one or more third properties and to provide control signals to the traffic using the estimated one or more third properties; and
a satellite navigation service 28 arranged to receive said estimated one or more third properties and to provide navigation services to one or more vehicles within the road network using the estimated one or more third properties.

### Claim 22

canceled