Take the wheel: Effects of available modalities on driver intervention

While automated driving systems will become increasingly capable and common in the future, there will still be instances when human drivers want or need to make corrections to the car's automated driving behavior. We conducted two studies exploring how driving interfaces could be designed to better execute the drivers' intentions. In our first study, adult participants (N=40) experienced a simulated driving scenario that varied the behavior of the car's automation (perfect driving and imperfect driving) and the intervention modalities (takeover and takeover+influence). At certain segments, the car's automation would drive perfectly or weave within the lane. During those times, participants could intervene using the available modalities. When experiencing instances of imperfect driving, drivers who had the ability to takeover+influence intervened more often than drivers who were only given the option to takeover. As intervening would require them to resume full control, drivers in the takeover condition were more tolerant of the imperfect driving. Also, most drivers tried to intervene initially by influencing the car, even those drivers who were only given the ability to takeover. In our second study, we examined how participants (N=40) of different demographics (high school students and seniors) would respond when they were subjected to the imperfect driving scenarios. High school drivers intervened just as much as the adult drivers. However, senior drivers intervened far less. These two studies suggest that when intervention is necessary, human drivers have a desire for shared control, which allows them to act as supervisors rather than operators of automated vehicles.