The number of assistance systems in cars has been increasing in recent years. While these systems are targeted at supporting the individual driver and his or her safety, they may though compete for the driver's attention, and may demand too much of the driver's cognitive resources. Based on the established multiple resource theory in recent years, the use of different multimodal displays has been investigated that give the driver attention while not overloading sensory channels. In our work, we are looking into peripheral light displays in means to present safety relevant information. In this paper, we present the results of an experiment in which a peripheral light display was used to show the distance to a closing vehicle. The display is an LED stripe, seamlessly integrated into the side door and the dashboard of the car. Two different light patterns were tested in an overtaking scenario in a driving simulator. One pattern encodes the expected time to collision to the left rear car by moving a light source towards the front left corner. The other pattern additionally adapts its brightness to a simplified model of the driver's certainty to get his or her attention in uncertain situations. In contrast to previous works, we did not focus on a warning system but on a decision aid system. We found that using the  adaptive  pattern led to faster decisions and therefore to a smaller probability of violating safety distances. We believe that this pattern is a good basis for patterns which are fine-tuned to individual drivers as well as better driver models.
['Andreas Löcken', 'Wilko Heuten', 'Susanne Boll']
Supporting lane change decisions with ambient light