Improving clarity, cooperation and driver experience in lane change maneuvers

Many situations in traffic involve multiple road users and can only be solved by successful cooperation. However, 30% of cooperations in traffic fail, which indicates that there is potential for improvement (Benmimoun, Neunzig & Maag, 2004). In this study, lane change maneuvers were examined as a typical example of a situation that requires cooperation. Two ways of enhancing lane change maneuvers have been tested. Firstly, a contact-analogue head-up display has been used to support the regular turn signal. Secondly, the meaning of the regular turn signals has been revisited and a set of enhanced semantics that allows a distinction between planning and starting a maneuver has been proposed and assessed. This rephrasing of the meaning was based on evidence that suggested that regular turn signals might be unable to clearly and unambigiously communicate intentions between drivers in cooperative maneuvers (Haar, Kleen, Schmettow & Verwey, 2017). In order to evaluate the two approaches, a simulator study with 52 participants has been carried out to investigate the effect of using a contact-analogue HUD and the enhanced semantics on cooperation, clarity and the general perception of the situation. The participants were asked to drive on the left lane of a highway and encountered several situations in which another driver attempted to change to the participant’s lane. On the one hand, objective measurements of cooperation have been obtained by counting the number of times that the participants allowed other drivers to change lanes. On the other hand, the participants were asked to fill in questionnaires to obtain subjective measurements of cooperative behavior, clarity and the way in which the driver experienced the situation. The results suggest that both approaches are beneficial for increasing the amount of cooperative behavior and in promoting the impression that other drivers are behaving cooperatively. Furthermore, the enhanced semantics improved the ability of participants to predict when exactly another driver initiated a lane change and what another driver was planning to do. Moreover, the lane change situations were rated as being a safer, more efficient and more comfortable experience when the HUD or the enhanced semantics were used. Keywords: cooperation, head-up display, HUD, augmented reality, lane change, collaboration, turn signal