MONITORING HEAD MOVEMENTS OF DRIVERS TASKED WITH MONITORING A VEHICLE OPERATING IN AN AUTONOMOUS DRIVING MODE

Aspects of the disclosure relate to analyzing head movements in a test driver tasked with monitoring the driving of a vehicle operating in an autonomous driving mode. For instance, a sensor may be used to capture sensor data of a test driver's head for a period of time. The sensor data may be analyzed to determine whether the test driver's head moved sufficiently enough to suggest that the test driver is engaged in monitoring the driving of the vehicle. Based on the determination of whether the test driver's head moved sufficiently enough, an intervention response may be initiated.