Vehicle travel control device

1. A vehicle travel control device comprising:

at least one processor; and

at least one machine readable tangible medium storing instructions that, when executed by the at least one processor, cause the at least one processor:

collect travel environment information of a first vehicle;

perform travel control of the first vehicle on a basis of the collected travel environment information; and

when the first vehicle traveling in is-a nonpriority lane performs a lane change to a priority lane into which the nonpriority lane is merged, perform a control based on lane boundary lines, wherein

the nonpriority lane includes a parallel segment extending parallel to the priority lane,

the lane boundary lines include:

a first lane boundary line indicating a boundary line between the priority lane and the nonpriority lane; and

a second lane boundary line including (i) a first portion extending parallel to the first lane boundary line at a position closer to a roadside than the first lane boundary line and defining the nonpriority lane along with the first lane boundary line, and (ii) a second portion extending diagonally from the first portion to the first lane boundary line to terminate the nonpriority lane,

the at least one processor is configured to:

execute, based on determining that a distance of a predetermined segment of the nonpriority lane is less than a first predetermined distance, a lane-shape-based lane-change control process; and

unexecute, based on determining that the distance of the predetermined segment of the nonpriority lane is greater than the first predetermined distance, the lane-shape-based lane-change control process, and

the lane-shape-based lane-change control process is a process causing the first vehicle to move along a target travel path from the nonpriority lane to the priority lane over the first lane boundary line such that the target travel path or a side surface in a vehicle width direction of the first vehicle that travels along the target travel path is parallel to the second portion of the second lane boundary line.

2. The vehicle travel control device according to claim 1 ,

wherein the at least one processor is configured to identify a predicted time point at which the first vehicle is to pass through the target travel path in a traveling direction of the first vehicle on the basis of the collected travel environment information, and

wherein, when the at least one processor determines that a second vehicle is to hinder the first vehicle from pass through the target travel path at the predicted time point, the at least one processor is configured to perform deceleration control before the predicted time point is reached.

3. The vehicle travel control device according to claim 1 , wherein the lane-shape-based lane-change control process includes obtaining the target travel path by parallel-shifting a curve line along at least a part of the second lane boundary line toward a center of the nonpriority lane.

4. The vehicle travel control device according to claim 1 , wherein the predetermined segment is a parallel segment of the nonpriority lane extending parallel to the priority road, or a remaining segment from the first vehicle that travels in the parallel segment to an end of the parallel segment.

5. The vehicle travel control device according to claim 1 , wherein the at least one processor is configured to execute, when the at least one processor unexecutes the lane-shape-based lane-change control process, a normal process that is a process causing the first vehicle to move along a target travel path from the nonpriority lane to the priority lane over the first lane boundary line without a shape of the second portion of the second lane boundary line.

6. A vehicle travel control device comprising:

circuitry configured to

collect travel environment information of a first vehicle,

perform travel control of the first vehicle on a basis of the collected travel environment information, and

when the first vehicle traveling in is-a nonpriority lane performs a lane change to a priority lane into which the nonpriority lane, perform a control based on lane boundary lines, wherein

the nonpriority lane includes a parallel segment extending parallel to the priority lane,

the lane boundary lines include:

a first lane boundary line indicating a boundary line between the priority lane and the nonpriority lane; and

a second lane boundary line including (i) a first portion extending parallel to the first lane boundary line at a position closer to a roadside than the first lane boundary line and defining the nonpriority lane along with the first lane boundary line, and (ii) a second portion extending diagonally from the first portion to the first lane boundary line to terminate the nonpriority lane,

the circuitry is configured to:

execute, based on determining that a distance of a predetermined segment of the nonpriority lane is less than a first predetermined distance, a lane-shape-based lane-change control process; and

unexecute, based on determining that the distance of the predetermined segment of the nonpriority lane is greater than the first predetermined distance, the lane-shape-based lane-change control process, and

the lane-shape-based lane-change control process is a process causing the first vehicle to move along a target travel path from the nonpriority lane to the priority lane over the first lane boundary line such that the target travel path or a side surface in a vehicle width direction of the first vehicle that travels along the target travel path is parallel to the second portion of the second lane boundary line.