Signal control system, apparatus, method, and computer-readable medium

1 . A signal control apparatus comprising:

a memory storing instructions; and

at least one processor configured to execute the instructions to:

detect a vehicle present in a lane from which a vehicle entering an intersection at which a traffic light is installed from a first direction crosses an opposite lane and turns left, and a vehicle entering the lane;

measure a flow of traffic of an oncoming vehicle that travels in an opposite lane from a second direction opposite to the first direction, enters the intersection, and passes through the intersection;

acquire a traffic condition comprising a speed of the oncoming vehicle based on information obtained from the measured flow of the traffic of the oncoming vehicle;

acquire an intersection entry time indicating a time until the oncoming vehicle reaches the intersection;

predict an intersection entry time point at which the oncoming vehicle enters the intersection based on the intersection entry time; and

control signal indications of a first traffic light and a second traffic light which control traffic of vehicles entering the intersection from the first direction and the second direction, respectively, wherein

the signal indication comprises a signal indication for facilitating the left turn, and

the at least one processor is configured to:

execute the instructions to control a timing of the signal indication for facilitating the left turn based on the predicted intersection entry time point and a time point corresponding to a predetermined timing for starting the signal indication for facilitating the left turn in a signal indication cycle;

determine, based on the predicted intersection entry time point, whether or not the oncoming vehicle enters the intersection until a time point at which passage on the straight traveling side is not allowed; and

in a case where it is determined that the oncoming vehicle does not enter the intersection until the time point at which passage on the straight traveling side is not allowed, determine to advance the timing of the signal indication for facilitating the left turn.

2 . The signal control apparatus according to claim 1 , wherein the at least one processor is configured to execute the instructions to perform the signal indication for facilitating the left turn by allowing traffic in a direction of the left turn to proceed at the first traffic light and prohibiting travel in a right-turning direction and a straight-traveling direction at the second traffic light.

3 . The signal control apparatus according to claim 1 , wherein the at least one processor is configured to execute the instructions to perform the signal indication for facilitating the left turn by turning on a left-turn arrow signal at the first traffic light, and turning on a red signal at the second traffic light.

4 . The signal control apparatus according to claim 1 , wherein the at least one processor is configured to execute the instructions to allow traffic in a direction of traveling straight through the intersection to proceed at the first traffic light in at least a part of a period in which the signal indication for facilitating the left turn is performed.

5 . The signal control apparatus according to claim 1 , wherein the at least one processor is configured to execute the instructions to perform a time difference indication between the first direction and the second direction in the signal indication for facilitating the left turn.

6 . The signal control apparatus according to claim 1 , wherein the at least one processor is configured to execute the instructions to determine, based on the predicted intersection entry time point, whether or not there is a second oncoming vehicle entering the intersection from the second direction for a period until the time point corresponding to the predetermined timing, and start the signal indication for facilitating the left turn at a timing earlier than the predetermined timing upon determining that there is no oncoming vehicle.

7 . The signal control apparatus according to claim 1 , wherein

the at least one processor is configured to execute the instructions to:

measure a position and the speed of the oncoming vehicle, and

calculate the intersection entry time based on the speed of the oncoming vehicle and a distance from the oncoming vehicle to the intersection.

8 . The signal control apparatus according to claim 1 , wherein the traffic light control means controls the timing of the signal indication for facilitating the left turn without changing an overall time of the signal indication cycle.

9 . The signal control apparatus according to claim 1 , wherein the at least one processor is configured to execute the instructions to detect the vehicle present in the lane from which the vehicle turns left, and the vehicle entering the lane from images acquired from one or more first image capturing devices configured to capture an image of the lane.

10 . The signal control apparatus according to claim 1 , wherein the at least one processor is configured to execute the instructions to measure the flow of the traffic of the oncoming vehicle from an image acquired from a second image capturing device configured to capture an image of an upstream side of the intersection of the opposite lane.

11 . The signal control apparatus according to claim 1 , wherein the at least one processor is further configured to execute the instructions to:

detect a vehicle staying in the lane, and

determine whether or not a vehicle stays in the lane based on a detection result of the vehicle staying in the lane, and shorten a duration of the signal indication for facilitating the left turn when it is determined that the vehicle does not stay in the lane.

12 . The signal control apparatus according to claim 11 , wherein the at least one processor is configured to execute the instructions to detect a vehicle line length formed in the lane.

13 . A signal control system comprising:

the first traffic light configured to control traffic of a vehicle entering the intersection from the first direction;

the second traffic light configured to control traffic of a vehicle entering the intersection from the second direction opposite to the first direction; and

the signal control apparatus according to claim 1 .

14 . The signal control system according to claim 13 , wherein the at least one processor is configured to execute the instructions to perform the signal indication for facilitating the left turn by allowing traffic in a direction of the left turn at the intersection to proceed at the first traffic light and prohibiting travel in a direction of traveling straight through the intersection at the second traffic light.

15 . A signal control method comprising:

detecting a vehicle present in a lane from which a vehicle entering an intersection at which a traffic light is installed from a first direction crosses an opposite lane and turns left, and a vehicle entering the lane;

measuring a flow of traffic of an oncoming vehicle that travels in the opposite lane from a second direction opposite to the first direction, enters the intersection, and passes through the intersection;

acquiring a traffic condition comprising a speed of the oncoming vehicle based on the measured flow of the traffic of the oncoming vehicle;

acquiring an intersection entry time indicating a time until the oncoming vehicle reaches the intersection;

predicting an intersection entry time point at which the oncoming vehicle enters the intersection based on the intersection entry time;

controlling a timing of a signal indication for facilitating the left turn-in controlling signal indications of a first traffic light and a second traffic light configured to control traffic of vehicles entering the intersection from the first direction and the second direction, respectively, based on the predicted intersection entry time point and a time point corresponding to a predetermined timing for starting the signal indication for facilitating the left turn in a signal indication cycle;

determining, based on the predicted intersection entry time point, whether or not the oncoming vehicle enters the intersection until a time point at which passage on the straight traveling side is not allowed; and

determining, in a case where it is determined that the oncoming vehicle does not enter the intersection until the time point at which passage on the straight traveling side is not allowed, to advance the timing of the signal indication for facilitating the left turn.

16 . A non-transitory computer-readable medium storing a program for causing a computer to execute a process comprising:

detecting a vehicle present in a lane from which a vehicle entering an intersection at which a traffic light is installed from a first direction crosses an opposite lane and turns left, and a vehicle entering the lane;

measuring a flow of traffic of an oncoming vehicle that travels in the opposite lane from a second direction opposite to the first direction, enters the intersection, and passes through the intersection;

acquiring a traffic condition comprising a speed of the oncoming vehicle based on the measured flow of the traffic of the oncoming vehicle;

acquiring an intersection entry time indicating a time until the oncoming vehicle reaches the intersection;

predicting an intersection entry time point at which the oncoming vehicle enters the intersection based on the intersection entry time;

controlling a timing of a signal indication for facilitating the left turn in controlling signal indications of a first traffic light and a second traffic light configured to control traffic of vehicles entering the intersection from the first direction and the second direction, respectively, based on the predicted intersection entry time point and a time point corresponding to a predetermined timing for starting the signal indication for facilitating the left turn in a signal indication cycle;

determining, based on the predicted intersection entry time point, whether or not the oncoming vehicle enters the intersection until a time point at which passage on the straight traveling side is not allowed; and

determining, in a case where it is determined that the oncoming vehicle does not enter the intersection until the time point at which passage on the straight traveling side is not allowed, to advance the timing of the signal indication for facilitating the left turn.