An experiment on ambient light patterns to support lane change decisions

In the recent years, several automotive manufacturers started to integrate ambient light displays into cars to increase drivers´ comfort. Expanding their possible application areas, we propose a display that continuously informs the driver of the vehicle´s as well as the environment´s state. We studied this display in a lane change maneuver, in which a driver has to decide if he or she can change lane in front of a faster closing car or brake to keep a safe distance to a slower car in front. We present results of an experiment for light patterns that are based on results of a design workshop and definitions for lane change decision aid systems (LCDAS) of ISO 17387. Though we used ISO´s definitions for the timings, our participants felt that status updates on the display came too late. In addition, the abrupt warnings, implemented in one of the tested patterns, led to worse performance of the participants. On the other hand, we observed that participants liked a continuous encoding of the time-to-collision (TTC) and observed a decrease in missed opportunities to overtake. Therefore, we argue that the defined limits for the warning levels are not well suited to support drivers during decision making in our scenario. Our contribution lies in a novel way of supporting drivers during lane change using an ambient in-vehicle light display. We showed that a continuous light pattern might help drivers in decision making, while more research has to be done to validate this.