The car used to be a symbol of freedom. The steering wheel allowed us to choose direction and drive where-ever we wanted. The self-driving car will change this. We’ll regain the freedom to do whatever we want - drink alcohol and use smartphones - while driving, but we have to give away a little control. Not everyone can accept this easily, Stewart could help people to get used to giving more control to the car.
Stewart is a tactile interface designed by Felix Ros, that mediates the communication between human and self-driving car. By getting into a dialogue with the car, the driver can start building a relationship of trust with the vehicle.
Stewart tells the driver the intentions of the car, this information gives the driver a sense of control. If the driver disagrees he or she could go into a conversation with the car by pushing Stewart into a different direction. Stewart will then make an estimation of how reasonable the driver's intentions are. If the driver tries to do something unsafe, Stewart will resist. This way Stewart “tells” the driver his or her actions aren't safe.
It could also be the driver wants to take another route than the one planned by the car. Humans are unpredictable and frequently change their plans. Stewart can mediate the drivers request and keep the driving safe. The car can learn from the communication with the driver. By getting to know the character of the driver the car can adjust the route to the wishes of the driver.