Dual-target hazard perception: Could identifying one hazard hinder a driver's capacity to find a second?

Awakening the Disengaged: Can Driving-Related Prompts Engage Drivers in Partial Automation?

OBJECTIVE

This study explores the effectiveness of conversational prompts on enhancing driver monitoring behavior and takeover performance in partially automated driving under two non-driving-related task (NDRT) scenarios with varying workloads.

BACKGROUND

Driver disengagement in partially automated driving is a serious safety concern. Intermittent conversational prompts that require responses may be a solution. However, existing literature is limited with inconsistent findings. There is little consideration of NDRTs as an important context, despite their ubiquitous involvement. A method is also lacking to measure driver engagement at the cognitive level, beyond manual and visual engagements.

METHODS

Participants operated a partially automated vehicle in a simulator across six predefined drives. In each drive, participants either received driving-related prompts, daily-conversation prompts, or no prompts, with or without a takeover notification. The first experiment instructed participants to engage in NDRTs at their choice and the second experiment incentivized solving demanding anagrams with monetary rewards.

RESULTS

When participants were voluntarily engaged in NDRTs, answering driving-related prompts and receiving takeover notifications improved their monitoring behavior and takeover performance. However, when participants were involved in the more demanding and incentivized NDRT, answering prompts had little effect.

CONCLUSION

The study supports the importance of both maintaining appropriate workload and processing driving-related information during partially automated driving. Driving-related prompts improve driver engagement and takeover performance, but they are not robust enough to compete with NDRTs that have high motivational appeals and cognitive demands.

APPLICATION

The design of driver engagement tools should consider the workload and information processing mechanisms.

Analysis of hazard perception characteristics based on driving behavior considering overt and covert hazard scenarios

The drivers’ hazard perception plays an important role in preventing and reducing the occurrence of traffic accidents. In order to explore the drivers’ hazard perception and their behavioral characteristics in overt and covert hazards, hazardous events of three traffic conflict types (vehicle to vehicle, vehicle to cyclist and vehicle to pedestrian) were designed for overt and covert hazards based on the UC-win/Road driving simulation software, respectively. 35 drivers were organized to conduct the driving simulation tests. The data of driving behavior was collected when they were driving. A comparative analysis of drivers’ hazard perception ability and driving behavior characteristics was carried out for hazardous scenarios and traffic conflict types. The result has shown that drivers are more likely to take slowing measures or brake earlier in overt hazard scenarios to ensure safe driving. And drivers are more likely to be involved in collisions in covert hazard scenarios. The types of traffic conflict have a significant effect on the hazard perception ability of drivers (F = 5.92, p < 0.01). Drivers have the strongest hazard perception for cyclists and the weakest hazard perception for pedestrians. Traffic conflict types has a significant effect on drivers’ average braking depth (F = 32.31, p < 0.01), average speed (F = 13.78, p < 0.01), and average acceleration (F = 9.26, p < 0.01).

The effect of categorical superiority in subsequent search misses

Subsequent search misses (SSM) refer to the decrease in accuracy of second target detection in dual-target visual search. One of the theoretical explanations of SSM errors is similarity bias - the tendency to search for similar targets and to miss the dissimilar ones. The current study focuses on both perceptual and categorical similarity and their individual roles in SSM. Five experiments investigated the role of perceptual and categorical similarity in subsequent search misses, wherein perceptual and categorical similarities were manipulated separately, and task relevance was controlled. The role of both perceptual and categorical similarity was revealed, however, the categorical similarity had greater impact on second target detection. The findings of this research suggest the revision of the traditional perceptual set hypothesis that mainly focuses on perceptual target similarity in multiple target visual search.

From "satisfaction of search" to "subsequent search misses": a review of multiple-target search errors across radiology and cognitive science

For over 50 years, the satisfaction of search effect has been studied within the field of radiology. Defined as a decrease in detection rates for a subsequent target when an initial target is found within the image, these multiple target errors are known to underlie errors of omission (e.g., a radiologist is more likely to miss an abnormality if another abnormality is identified). More recently, they have also been found to underlie lab-based search errors in cognitive science experiments (e.g., an observer is more likely to miss a target 'T' if a different target 'T' was detected). This phenomenon was renamed the subsequent search miss (SSM) effect in cognitive science. Here we review the SSM literature in both radiology and cognitive science and discuss: (1) the current SSM theories (i.e., satisfaction, perceptual set, and resource depletion theories), (2) the eye movement errors that underlie the SSM effect, (3) the existing efforts tested to alleviate SSM errors, and (4) the evolution of methodologies and analyses used when calculating the SSM effect. Finally, we present the attentional template theory, a novel mechanistic explanation for SSM errors, which ties together our current understanding of SSM errors and the attentional template literature.