The present embodiments may relate to determining an actual driver of a vehicle based upon telematics data. For instance, a driver identification (DI) computing device may be configured to: (1) receive a first plurality of measurements captured at a first user device during a trip taken by a vehicle; (2) receive a second plurality of measurements captured at a second user device during the trip; (3) determine, based upon the measurements, that the user devices are within the vehicle during the trip; (4) calculate a respective enhanced geographic location measurement for each of the measurements based upon the measurements; (5) determine, based upon the enhanced geographic location measurements, a predicted position of the second user device relative to the first user device; and (6) identify, from among the user devices, a driver user device based upon the predicted position of the second user device relative to the first user device.