A platooning system including vehicles, the platooning system being configured such that the vehicles form a platoon to travel, the vehicles including a lead vehicle and a subsequent vehicle configured to follow the lead vehicle through self-driving, wherein the lead vehicle includes: a steering information acquisition unit (32, 33, 34, 35) configured to acquire steering information related to steering of the lead vehicle, the steering information indicating a steering angle of the lead vehicle; and a sender configured to send, to the subsequent vehicle, the steering information that indicates the steering angle and that has been acquired by the steering information acquisition unit, and the subsequent vehicle includes: a receiver configured to receive the steering information; and a self-driving controller configured to start control of a steering angle to avoid a collision with an obstacle when the steering information indicates execution of sudden steering to avoid the collision with the obstacle, wherein the self-driving controller is configured to determine that the lead vehicle has been suddenly steered when a change in the steering angle that is based on the steering information exceeds a normal range, the subsequent vehicle is configured to selectively execute a normal following control to follow the lead vehicle such that the subsequent vehicle travels so as to trace a path for the lead vehicle and a collision avoidance control such that the subsequent vehicle follows the lead vehicle by traveling without tracing the path for the lead vehicle, the subsequent vehicle is configured to select the collision avoidance control when the steering information indicates the execution of the sudden steering to avoid the collision with the obstacle, and in the case of executing the collision avoidance control the subsequent vehicle travels from its position toward the lead vehicle such that a path (200a, 300a) for the subsequent vehicle has a shape extending straight from its position toward the side of the obstacle. the lead vehicle includes: a steering information acquisition unit (32, 33, 34, 35) configured to acquire steering information related to steering of the lead vehicle, the steering information indicating a steering angle of the lead vehicle; and a sender configured to send, to the subsequent vehicle, the steering information that indicates the steering angle and that has been acquired by the steering information acquisition unit, and a steering information acquisition unit (32, 33, 34, 35) configured to acquire steering information related to steering of the lead vehicle, the steering information indicating a steering angle of the lead vehicle; and a sender configured to send, to the subsequent vehicle, the steering information that indicates the steering angle and that has been acquired by the steering information acquisition unit, and the subsequent vehicle includes: a receiver configured to receive the steering information; and a self-driving controller configured to start control of a steering angle to avoid a collision with an obstacle when the steering information indicates execution of sudden steering to avoid the collision with the obstacle, wherein a receiver configured to receive the steering information; and a self-driving controller configured to start control of a steering angle to avoid a collision with an obstacle when the steering information indicates execution of sudden steering to avoid the collision with the obstacle, wherein the self-driving controller is configured to determine that the lead vehicle has been suddenly steered when a change in the steering angle that is based on the steering information exceeds a normal range, the subsequent vehicle is configured to selectively execute a normal following control to follow the lead vehicle such that the subsequent vehicle travels so as to trace a path for the lead vehicle and a collision avoidance control such that the subsequent vehicle follows the lead vehicle by traveling without tracing the path for the lead vehicle, the subsequent vehicle is configured to select the collision avoidance control when the steering information indicates the execution of the sudden steering to avoid the collision with the obstacle, and in the case of executing the collision avoidance control the subsequent vehicle travels from its position toward the lead vehicle such that a path (200a, 300a) for the subsequent vehicle has a shape extending straight from its position toward the side of the obstacle.