In Ohio, an owner of a car is liable if the owner negligently entrusts the car to an incompetent driver. A person can be incompetent if he or she is inexperienced in driving a car, has a long history of traffic citations or prior accidents, or has a history of driving under the influence of alcohol or other drugs. The owner or entruster must be aware of this incompetence or reasonably should be aware of these things.
It used to be that only the owner of a car could be charged with negligent entrustment. However, in a recent case a teenager who was not the owner of a car (his mother was), allowed another friend to drive the vehicle. When the friend was in an accident, the injured party also sought recovery from the teenager who let the bad driver get behind the wheel of the car.