a running environment recognizer configured to recognize running environment in front of the vehicle;

a preceding vehicle information acquirer configured to acquire information about a preceding vehicle based on the running environment recognized by the running environment recognizer to detect, from the acquired information about the preceding vehicle, a vehicle class of the preceding vehicle and variation in behavior of the preceding vehicle;

an amount-of-steering control calculator configured to calculate an amount of steering control to cause the vehicle to run along a target path of travel set on a lane;

a disturbance estimation control calculator configured to estimate, based on the vehicle class and the variation in the behavior, lateral-direction disturbance received by the preceding vehicle to calculate an amount of steering against the disturbance based on the estimated disturbance; and

a coordination controller configured to correct the amount of steering control calculated by the amount-of-steering control calculator with the amount of steering calculated by the disturbance estimation control calculator to set a new amount of steering control,

wherein the disturbance estimation control calculator is configured to

check a rolling direction and a lateral motion direction of the preceding vehicle from the variation in the behavior of the preceding vehicle, and

in a case where the rolling direction coincides with the lateral motion direction, determine that the variation in the behavior of the preceding vehicle is caused by the disturbance, and calculate the amount of steering.