A method implemented using one or more processors, the method comprising: receiving sensor data from one or more sensors at a vehicle; identifying, based on the sensor data, one or more risk sources encountered by the vehicle during a period of operation of the vehicle; identifying, based on the sensor data, one or more safety events experienced by the vehicle with respect to the one or more risk sources during the period of operation of the vehicle; determining, based on the one or more safety events and the one or more risk sources, a risk of a safety event for the period of operation of the vehicle; characterized in that the method further comprises: adjusting the risk of the safety event for the period of operation of the vehicle based on data representing a normalized risk of a safety event for a normalized period of operation different from the period of operation of the vehicle; and determining, based on the one or more safety events and the adjusted risk for the period of operation of the vehicle, a safety performance of the vehicle or a driver of the vehicle during the period of operation of the vehicle. the method comprising: receiving sensor data from one or more sensors at a vehicle; identifying, based on the sensor data, one or more risk sources encountered by the vehicle during a period of operation of the vehicle; identifying, based on the sensor data, one or more safety events experienced by the vehicle with respect to the one or more risk sources during the period of operation of the vehicle; determining, based on the one or more safety events and the one or more risk sources, a risk of a safety event for the period of operation of the vehicle; receiving sensor data from one or more sensors at a vehicle; identifying, based on the sensor data, one or more risk sources encountered by the vehicle during a period of operation of the vehicle; identifying, based on the sensor data, one or more safety events experienced by the vehicle with respect to the one or more risk sources during the period of operation of the vehicle; determining, based on the one or more safety events and the one or more risk sources, a risk of a safety event for the period of operation of the vehicle; characterized in that the method further comprises: adjusting the risk of the safety event for the period of operation of the vehicle based on data representing a normalized risk of a safety event for a normalized period of operation different from the period of operation of the vehicle; and determining, based on the one or more safety events and the adjusted risk for the period of operation of the vehicle, a safety performance of the vehicle or a driver of the vehicle during the period of operation of the vehicle. adjusting the risk of the safety event for the period of operation of the vehicle based on data representing a normalized risk of a safety event for a normalized period of operation different from the period of operation of the vehicle; and determining, based on the one or more safety events and the adjusted risk for the period of operation of the vehicle, a safety performance of the vehicle or a driver of the vehicle during the period of operation of the vehicle.