The Effects of Vehicle Automation on Driver Engagement: The Case of Adaptive Cruise Control and Mind Wandering.

OBJECTIVE: This field study examined the effects of adaptive cruise control (ACC) on mind wandering prevalence. BACKGROUND: ACC relieves the driver of the need to regulate vehicle speed and following distance, which may result in safety benefits. However, if ACC reduces the amount of attentional resources drivers must devote to driving, then drivers who use ACC may experience increased periods of mind wandering, which could reduce safety. METHODS: Participants drove a prescribed route on a public road twice, once using ACC and once driving manually. Mind wandering rates were assessed throughout the drive using auditory probes, which occurred at random intervals and required the participant to indicate whether or not they were mind wandering. Measures of physiological arousal and driving performance were also recorded. RESULTS: No evidence of increased mind wandering was found when drivers used ACC. In fact, female drivers reported reduced rates of mind wandering when driving with ACC relative to manual driving. Driving with ACC also tended to be associated with increased physiological arousal and improved driving behavior. CONCLUSION: Use of ACC did not encourage increased mind wandering or negatively affect driving performance. In fact, the results indicate that ACC may have positive effects on driver safety among drivers who have limited experience with the technology. APPLICATION: Driver characteristics, such as level of experience with in-vehicle technology and gender, should be considered when investigating driver engagement during ACC use. Field research on vehicle automation may provide valuable insights over and above studies conducted in driving simulators.

Pedestrians' estimates of their own visibility: a simple and effective computer-based technique.

INTRODUCTION: Research has shown that both pedestrians and drivers drastically overestimate pedestrians' nighttime visibility (NHSTSA, 2008a, 2008b; Owens & Sivak, 1996) and fail to appreciate the safety benefits of proven conspicuity aids. One solution is educational intervention (Tyrrell, Patton, & Brooks, 2004); however, the on-road assessment of its effectiveness is expensive and time consuming. METHOD: Experiment One introduces a computer-based alternative to the field-based approach, successfully replicating the previous study's trends among 94 students who either receive or do not receive an educational lecture. Experiment Two utilizes the simulation's portability to determine if professional roadway workers have a more accurate understanding of pedestrian conspicuity than students. RESULTS: RESULTS among 88 workers show they do not significantly appreciate the advantages of effective retroflective material configurations or vehicle headlamp settings, for example, any better than non-lectured students in Experiment One. IMPACT: The study's results demonstrate the need for education among all pedestrians and the benefits of efficient testing methods.

Highlighting human form and motion information enhances the conspicuity of pedestrians at night.

Exploring how biological motion can make pedestrians more conspicuous to drivers at night, one-hundred-and-twenty participants were driven along an open-road route at night and pressed a button whenever they recognized that a pedestrian was present. A test pedestrian wearing black clothing alone or with 302 cm2 of retroreflective markings in one of four configurations either stood still or walked in place on an unilluminated sidewalk. Participants' response distances were maximal for the full biological-motion configuration and remained surprisingly long when convenient subsets of reflective markers were positioned on the pedestrian's ankles and wrists. When the pedestrian wore a reflective vest, the responses were no better than when he wore no reflective markings. The biological-motion advantage actually results from interacting form-perception and motion-perception mechanisms. These results confirm that basic perceptual phenomena-observers' sensitivity to human form and motion can be harnessed to reduce an important problem of traffic safety.