Mercedes-Benz considers empathy and trust to be central factors for the acceptance of self-driving vehicles. For people to have trust in the machine, they must immediately and intuitively be able to recognise what an autonomous vehicle intends to do. Mercedes-Benz is conducting research into this “informed trust” with the help of the “cooperative car”.
The cooperative car is based on an S-Class, and features 360-degree light signaling. Turquoise lights on the roof indicate autonomous driving mode, and provide information on what happens next.
- Continuous light shows that the vehicle is in autonomous driving mode, whether moving or stationary.
Slow flashing means that the vehicle is braking.
Rapid flashing announces that the vehicle will shortly be moving off.
Alternative light display concepts are also being tested with this vehicle: turquoise light strips in the windscreen, the radiator grille, the headlamps, the exterior mirrors and the lower area of the windows indicate to pedestrians and other road users that the vehicle is operating in autonomous mode.
Short rows of illuminated dots on the roof tell other road users that they have been recognized. In the process, only those pedestrians or cyclists whose path coincides with that of the vehicle are given a light signal. In doing so, the cooperative car recreates the natural eye contact that would have taken place between the driver and pedestrians.
The cooperative S-Class also informs its surroundings that it is about to go into operation while it is still at the side of the road. The light strips around the vehicle emit an appropriate light signal. The exterior mirrors fold out, and first the rear then the front of the vehicle lifts up. These movements resemble a living being that is waking up and stretching. People can understand this communication intuitively, Mercedes-Benz suggests.
Studies have shown that pedestrians prefer 360-degree communication in turquoise. 360-degree light signalling is particularly important when it comes to keeping pedestrians informed. These are the findings from several light studies that Mercedes-Benz carried out in Sindelfingen and on the Immendingen test site, which was opened in September 2018.
The research examined how pedestrians react to differently signalized autonomous vehicles in various traffic situations. It became clear that light signaling has a strong effect on the acceptance of autonomously driving vehicles, as well as on how safe pedestrians feel.
In particular, people want light signaling in situations where there was hitherto interaction with the driver. For example, people are used to seeking eye contact with a driver when they want to cross a road. If light signaling is communicating that a vehicle is in the autonomous driving mode, pedestrians can feel safe even if the vehicle occupants are obviously not paying attention to the traffic situation.
The majority of participants in the study preferred turquoise as the signaling color; all participants favoured a 360-degree display. Mercedes-Benz is contributing its findings from these studies to assist work being carried out on autonomous driving by SAE International. There Mercedes-Benz recommends the use of turquoise, a color which has not previously been used in the automotive sector, to enable 360° signalling. . . .