A system and method of operation involves collecting acceleration and gyroscope data from a first sensor positioned in a wearable device on a user's wrist and a second sensor located in a mobile device. The mobile device determines a trajectory for the wearable device by filtering the first sensor data using the second sensor data, and determines a probability of the user holding an automobile steering wheel using the trajectory. The method may also include determining a probability of the user holding an automobile steering wheel of a specific automobile selected from an automobile list. The disclosed system includes the wearable device and the mobile device.