The techniques of this disclosure relate to a driver-monitoring system. The system includes a controller circuit that receives monitoring data from a driver-monitor sensor that is configured to monitor a driver of a vehicle while the vehicle operates in an autonomous-driving mode. The controller circuit determines a score of one or more driver-supervisory metrics based on the monitoring data, each of the driver-supervisory metrics being indicative of whether the driver is supervising the operation of the vehicle. The controller circuit determines a supervision score based on the score of the driver-supervisory metrics. The supervision score is indicative of whether the driver is ready to resume control of the vehicle. The controller circuit indicates a driver-awareness status on a display in a field of view of the driver based on the supervision score. The system can improve vehicle safety by alerting the driver when the driver exhibits reduced driver awareness behavior.