End-users perspective matters in ADAS: designing a blind-spot alert system from a user-centered approach

The number of traffic accidents involving motorcycles has been increasing in Brazil recently. Many accidents are caused by drivers who do not see motorcycles approaching in the vehicle blind spots. Advanced Driver Assistance Systems (ADAS) installed in vehicles can be used to mitigate this problem. However, the development of ADASs often focuses on security issues and does not consider the user experience with the ADASs interface. In this paper, we present the design of an alerting system that warns drivers about collision risks when motorcycles are identified in vehicle blind spots. Our proposal alerts drivers by using visual and haptic interaction modes. In line with a user-centered design methodology, our initial action involved identifying the traits of the target users in order to create personas that embody their characteristics. The vehicle blind spot alert system was conceived in a co-design session using the personas elaborated previously. In the session, 9 end-users produced 3 low-fidelity (lo-fi) prototypes which were analyzed and compiled generating a single lo-fi prototype. After promoting a viability discussion, a high-fidelity (hi-fi) prototype containing haptic and visual alerting features was implemented and installed in a car for testing. The alert system was evaluated by 20 end-users concerning their experience with the different warning modes. The results showed that for both the visual and haptic modes, users could recognize and understand the alerts without employing a great effort in the information interpretation. This result reinforces the idea that ADASs should provide simple interpretative interfaces because drivers' interaction with these systems should be a secondary activity since their concentration must be on driving.