An autonomous vehicle may operate in an environment in which there is an unexpected dynamic object. The autonomous vehicle can detect the dynamic object. The dynamic object can have an associated movement. The movement of the dynamic object can be tracked. The movement of the dynamic object can be classified as being one ballistic or non-ballistic. It can be determined whether the dynamic object is on a collision course with the autonomous vehicle. Responsive to determining that the dynamic object is on a collision course with the autonomous vehicle, a driving maneuver for the autonomous vehicle can be determined. The driving maneuver can be based at least in part on the movement of the dynamic object. The autonomous vehicle can be caused to implement the determined driving maneuver.