New cars that can steer and brake themselves risk lulling people in the driver's seat into a false sense of security - and even to sleep.<br />That was one surprising finding when researchers put Stanford University students in a simulated self-driving car to study how they reacted when their robo-chauffer needed help.<br />The experiment was one in a growing number that assesses how cars can safely hand control back to a person when their self-driving software and sensors are overwhelmed or overmatched.<br />There's no consensus on the right car-to-driver handoff approach: the Stanford research suggests engaging people with media could help, while some automakers are marketing vehicles with limited self-driving features that will slow the car if they detect a person has stopped paying attention to the road.<br />One potential hazard of this gradualist approach became clear this fall, when Tesla Motors had to explain that its "auto pilot" feature did not mean drivers could stop paying attention.
