COLLISION AVOIDANCE ASSISTANCE DEVICE AND COLLISION AVOIDANCE ASSISTANCE METHOD

A collision avoidance assistance device configured to perform driver steering assistance to avoid a collision between a vehicle and an obstacle, the device includes a steering control unit configured to perform the steering assistance in a case where it is determined that there is a possibility of the collision between the vehicle and the obstacle. During a period from commencement of the steering assistance to elapsing of a first time determined by response characteristics of a lateral acceleration of the vehicle, the steering control unit is configured to rotate a steering wheel of the vehicle in a collision avoidance direction by a control amount determined based on a steering holding force of the driver.