System and method for real-time assessment of traffic stream flow characteristics
The present disclosure relates to a system and method for updating traffic-related infrastructure. The method includes determining average traffic stream speed and average traffic density over a segment of a highway. The method further includes determining, upon analysis of the determined average traffic stream speed and average traffic density over a segment of a highway, an appropriate action in order to update the infrastructure.
1. A server, comprising:
processing circuitry configured to
receive sensor data from a plurality of sensors of a probe vehicle within a traffic stream,
determine, based at least on the received sensor data, an average traffic speed along a current road segment, the average traffic speed determined at least by calculating a speed of neighboring vehicles adjacent to a travelling lane of the probe vehicle, wherein the neighboring vehicles are successive, adjacent vehicles travelling on adjacent lanes of the travelling lane of the probe vehicle,
determine, based at least on the received sensor data, an average traffic density along the current road segment, the average traffic density determined at least by calculating distances between the probe vehicle and the neighboring vehicles adjacent thereto,
transmit, based at least on a comparison of the determined average traffic speed and the determined average traffic density to a threshold, an update to infrastructure in order to modify a condition of the traffic stream in real-time, and
control a condition of the traffic stream of the current road segment in response to the update to the infrastructure.
2. The server according to claim 1 , wherein the plurality of sensors of the probe vehicle includes sensors selected from a group including radar and lidar.
3. The server according to claim 1 , wherein, when one of the neighboring vehicles adjacent to the probe vehicle overtakes or is overtaken by the probe vehicle, the processing circuitry is further configured to
calculate a speed of the one of the neighboring vehicles adjacent to the probe vehicle based at least upon a distance between a subset of the plurality of sensors arranged along a side of the probe vehicle, a speed of the probe vehicle, and time stamps at which each of the subset of the plurality of sensors is activated or deactivated.
4. The server according to claim 3 , wherein the speed of the one of the neighboring vehicles adjacent to the probe vehicle overtaking or being over taken by the probe vehicle is calculated as
V
A
=
V
X
+
2
d
(
FR
-
BR
)
+
(
FF
-
BF
)
,
where V A is the speed of the one of the neighboring vehicles, V X is the speed of the probe vehicle, d is the distance between the subset of the plurality of sensors, FR and BR define the time stamps associated with activation of each of the subset of the plurality of sensors, and FF and BF define the time stamps associated with deactivation of each of the subset of the plurality of sensors.
5. The server according to claim 1 , wherein the processing circuitry is further configured to
calculate a distance of the distances between the probe vehicle and the neighboring vehicles adjacent thereto as
Gap
n
=
(
FR
n
+
1
-
FR
n
)
+
(
BR
n
+
1
-
BR
n
)
2
*
[
(
V
n
+
V
n
+
1
)
2
-
V
X
]
,
where Gap n is a distance between successive, adjacent vehicles of an adjacent lane, V n and V n+1 are speeds of successive, adjacent vehicles overtaking or being overtaken by the probe vehicle, V X is a speed of the probe vehicle, and FR n , FR n+1 , BR n , and BR n+1 define time stamps associated with activation of each of a subset of the plurality of sensors, a series of the time stamps being acquired for each of the successive, adjacent vehicles.
6. The server according to claim 5 , wherein the determined average traffic density is calculated as
D
avg
=
1
3
{
1
Gap
_
Left
+
2
R
_
Front
+
R
_
Back
+
1
+
Gap
_
Right
}
,
where D avg is the average traffic density for the current road segment, Gap Left is an average of calculated distances between successive, adjacent vehicles on a left side of the probe vehicle for the current road segment, Gap Right is an average of calculated distances between successive, adjacent vehicles on a right side of the probe vehicle for the current road segment, R Back is an average distance between a trailing vehicle and the probe vehicle, and R Front is an average distance between a leading vehicle and the probe vehicle.
7. The server according to claim 1 , wherein the update to the infrastructure includes adjusting a displayed speed limit for the current road segment.
8. The server according to claim 7 , wherein the adjustment to the displayed speed limit for the current road segment is based at least upon a determined level of service for the current road segment.
9. A method, comprising:
receiving, by processing circuitry, sensor data from a plurality of sensors of a probe vehicle within a traffic stream;
determining, by the processing circuitry and based at least on the received sensor data, an average traffic speed along a current road segment, the average traffic speed determined at least by calculating a speed of neighboring vehicles adjacent to a travelling lane of the probe vehicle, wherein the neighboring vehicles are successive, adjacent vehicles travelling on adjacent lanes of the travelling lane of the probe vehicle;
determining, by the processing circuitry and based at least on the received sensor data, an average traffic density along the current road segment, the average traffic density determined at least by calculating distances between the probe vehicle and the neighboring vehicles adjacent thereto;
transmitting, by the processing circuitry and based at least on a comparison of the determined average traffic speed and the determined average traffic density to a threshold, an update to infrastructure in order modify a condition of the traffic stream in real-time, and
controlling a condition of the traffic stream of the current road segment in response to the update to the infrastructure.
10. The method according to claim 9 , wherein the plurality of sensors of the probe vehicle includes sensors selected from a group including radar and lidar.
11. The method according to claim 9 , further comprising, when one of the neighboring vehicles adjacent to the probe vehicle overtakes or is overtaken by the probe vehicle,
calculating, by the processing circuitry, a speed of the one of the neighboring vehicles adjacent to the probe vehicle based at least upon a distance between a subset of the plurality of sensors arranged along a side of the probe vehicle, a speed of the probe vehicle, and time stamps at which each of the subset of the plurality of sensors is activated or deactivated.
12. The method according to claim 11 , wherein the speed of the one of the neighboring vehicles adjacent to the probe vehicle overtaking or being over taken by the probe vehicle is calculated as
V
A
=
V
X
+
2
d
(
FR
-
BR
)
+
(
FF
-
BF
)
,
where V A is the speed of the one of the neighboring vehicles, V X is the speed of the probe vehicle, d is the distance between the subset of the plurality of sensors, FR and BR define the time stamps associated with activation of each of the subset of the plurality of sensors, and FF and BF define the time stamps associated with deactivation of each of the subset of the plurality of sensors.
13. The method according to claim 9 , further comprising
calculating, by the processing circuitry, a distance of the distances between the probe vehicle and the neighboring vehicles adjacent thereto as
Gap
n
=
(
FR
n
+
1
-
FR
n
)
+
(
BR
n
+
1
-
BR
n
)
2
*
[
(
V
n
+
V
n
+
1
)
2
-
V
X
]
,
where Gap n is a distance between successive, adjacent vehicles of an adjacent lane, V n and V n+1 are speeds of successive, adjacent vehicles overtaking or being overtaken by the probe vehicle, V X is a speed of the probe vehicle, and FR n , FR n+1 , BR n , and BR n+1 define time stamps associated with activation of each of a subset of the plurality of sensors, a series of the time stamps being acquired for each of the successive, adjacent vehicles.
14. The method according to claim 13 , wherein the determined average traffic density is calculated as
D
avg
=
1
3
{
1
Gap
_
Left
+
2
R
_
Front
+
R
_
Back
+
1
+
Gap
_
Right
}
,
where D avg is the average traffic density for the current road segment, Gap Left is an average of calculated distances between successive, adjacent vehicles on a left side of the probe vehicle for the current road segment, Gap Right is an average of calculated distances between successive, adjacent vehicles on a right side of the probe vehicle for the current road segment, R Back is an average distance between a trailing vehicle and the probe vehicle, and R Front is an average distance between a leading vehicle and the probe vehicle.
15. The method according to claim 9 , wherein the update to the infrastructure includes adjusting a displayed speed limit for the current road segment.
16. The method according to claim 15 , wherein an adjustment to the displayed speed limit for the current road segment is based at least upon a determined level of service for the current road segment.
17. A non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a computer, cause the computer to perform a method of a server, comprising:
receiving sensor data from a plurality of sensors of a probe vehicle within a traffic stream;
determining, based at least on the received sensor data, an average traffic speed along a current road segment, the average traffic speed determined at least by calculating a speed of neighboring vehicles adjacent to a travelling lane of the probe vehicle, wherein the neighboring vehicles are successive, adjacent vehicles travelling on adjacent lanes of the travelling lane of the probe vehicle;
determining, based at least on the received sensor data, an average traffic density along the current road segment, the average traffic density determined at least by calculating distances between the probe vehicle and the neighboring vehicles adjacent thereto;
transmitting, based at least on a comparison of the determined average traffic speed and the determined average traffic density to a threshold, an update to infrastructure in order modify a condition of the traffic stream in real-time, and
controlling a condition of the traffic stream of the current road segment in response to the update to the infrastructure.
18. The non-transitory computer-readable storage medium according to claim 17 , wherein a speed of one of the neighboring vehicles adjacent to the probe vehicle overtaking or being over taken by the probe vehicle is calculated as
V
A
=
V
X
+
2
d
(
FR
-
BR
)
+
(
FF
-
BF
)
,
where V A is the speed of the one of the neighboring vehicles, V X is a speed of the probe vehicle, d is a distance between a subset of the plurality of sensors arranged along a side of the probe vehicle, FR and BR define time stamps associated with activation of each of the subset of the plurality of sensors, and FF and BF define time stamps associated with deactivation of each of the subset of the plurality of sensors.
19. The non-transitory computer-readable storage medium according to claim 18 , wherein the determined average traffic density is calculated as
D
avg
=
1
3
{
1
Gap
_
Left
+
2
R
_
Front
+
R
_
Back
+
1
+
Gap
_
Right
}
,
where D avg is the average traffic density for the current road segment, Gap Left is an average of calculated distances between successive, adjacent vehicles on a left side of the probe vehicle for the current road segment, Gap Right is an average of calculated distances between successive, adjacent vehicles on a right side of the probe vehicle for the current road segment, R Back is an average distance between a trailing vehicle and the probe vehicle, and R Front is an average distance between a leading vehicle and the probe vehicle.
20. The non-transitory computer-readable storage medium according to claim 17 , wherein the update to the infrastructure includes adjusting a displayed speed limit for the current road segment.