COLLISION DETECTION DEVICE

A collision detection device detects a probability of whether a vehicle will collide with a detected moving object. An ECU determines a high-risk region measured by a predetermined distance in a forward moving direction of the vehicle from a farthest feature point obtained from a farthest-located obstacle object detected on a road's shoulder. When the moving object is detected in the high-risk region, the ECU reduces a collision detection time-period within which the vehicle must detect whether the vehicle would collide with the moving object. The reduced collision detection time-period is shorter than a collision detection time-period to be used when the moving object is detected outside of the high-risk region.