DRIVING OPERATION DETERMINER, DRIVING OPERATION DETERMINATION SYSTEM, DRIVING OPERATION DETERMINATION METHOD, AND STORAGE MEDIUM STORING PROGRAM

A driving operation determiner that is configured to: based on lever operation information representing whether or not a turn signal lever of a vehicle is operated, and based on yaw rate information representing a yaw rate of the vehicle, make a determination as to whether, in an identified duration between a first time and a second time, a difference between a maximum value and a minimum value of the yaw rate is at least a first threshold value and an absolute value of the maximum value of the yaw rate is at least a second threshold value, the turn signal lever being switched from a non-operation state to an operation state at the first time, and the turn signal lever being switched from the operation state to the non-operation state at the second time subsequent to the first time.