  Traffic-related injuries and fatalities are major health risks in the United
States. Mobile phone use while driving quadruples the risk for a motor vehicle
crash. This work demonstrates the feasibility of using the mobile phone camera
to passively detect the location of the phone's user within a vehicle. In a
large, varied dataset we were able correctly identify if the user was in the
driver's seat or one of the passenger seats with 94.9% accuracy. This model
could be used by application developers to selectively change or lock
functionality while a user is driving, but not if the user is a passenger in a
moving vehicle.
