Charles A. Green

Design and Evaluation of a Prototype Rear Obstacle Detection and Driver Warning System

This study, concerned with the development of driver interface criteria for a rear obstacle detection system, assessed the appropriateness of alternative warning timing algorithms and evaluated various interface approaches for presenting warning information to drivers. Interface testing used a minivan and a passenger sedan equipped with a prototype rear obstacle detection system. Two different warning timing algorithms and four different interface conditions were examined. The appropriateness of the warning timing algorithms was tested using an alerted backing procedure wherein drivers backed to known obstacles and braked in response to the warning. A surprise event scenario was also included in order to examine driver reaction to the warning under unexpected conditions. Alerted backing results suggest that although both timing algorithms led to few target strikes, one algorithm led to more acceptable ratings, fewer target strikes and close calls, and less urgent braking. None of the interface warning conditions reliably induced avoidance braking under the surprise event condition. Actual or potential applications of this work include the appropriate design of effective backing warning systems.

SHORT NOTE Evaluation of Alternative Media Used with a Groupware Editor in a Simulated Telecommunications Environment

Writing efficiency using a groupware editor was evaluated in six configurations by factorially combining three communication media (audio only, audio plus video, and face-to-face) each with and without groupware editing in a within-subjects design. Twelve subjects familiar with journalistic writing were matched into dyads and wrote news articles based on sets of questions about video clips shown to them. The quality of the writing task products was consistently high and showed no differences among conditions. Results indicated that face-to-face conditions resulted in significantly less time to complete the task than did other communication conditions. When groupware editing was used, however, all communication media were equally efficient. The results were discussed in terms of the benefits of using the groupware editor to increase efficiency when face-to-face communication is not practical. Methodological procedures were discussed as a means of reducing team variability in evaluating groupware using telecommunications.

Strategies to Assist Drivers in Remaining Attentive While Under Partially Automated Driving: Verification of Human–Machine Interface Concepts

Visual inattention is a major concern with partially automated driving systems that assume vehicle steering functions. The safety concept for these systems capable of maintaining vehicle lane position and headway depends on an attentive driver who detects and appropriately responds to objects and events that are beyond the limitations of the sensors. Embedded within a proposed system are features designed to help drivers perform these functions and remain attentive to the driving environment. This study served to validate human–machine interface (HMI) strategies and concepts that can be applied to production-intent partially automated system HMI to achieve intended safety goals in assisting drivers to maintain attention to driving. Previous validation efforts, conducted as part of a NHTSA study, proved insufficient for verification of these driver performance functions since they relied on an incomplete version of alternative HMI concepts. The current study, with a sample of 25 licensed drivers, used approaches that more closely approximated the potential production-intent partially automated HMI concepts, including the introduction of consequences for failing to respond to alerts. Work was performed by using an advanced prototype capable of mimicking the basic functions afforded in a partially automated system. Driver responses to unexpected lane drift events were also examined. Results found that HMI concepts that introduce consequences for driver nonresponse situations substantially increase driver compliance to system cues, prompts, and alerts. Results of this study suggest that the potential production design partially automated system HMI concepts can assist drivers in maintaining their attention to driving.

Driver Hazard Detection and Avoidance Performance as a Function of Eyes-Off-Road Interval Under Partially Automated Driving

There has been concern that automation may impair a person’s ability to detect and appropriately respond to environmental hazards. This study sought to examine a driver’s ability to not only detect hazards, but also to implement appropriate responses following extended Eyes-Off-Road (EOR) intervals. Thirty-six drivers were exposed to a series of filmed roadway vignettes with discernible hazards embedded within a range of traffic situations. Driver’s visual gaze was directed “off-road” for 2, 7 or 20 seconds, and then re-oriented to the roadway. Drivers were tasked to respond appropriately as quickly as possible once their gaze returned to the forward road scene by steering and/or braking in response to the hazards. Results found no significant differences among the EOR intervals in terms of the driver’s ability to detect and appropriately respond to the hazard when it emerged after the driver’s eyes were directed forward.

Using a Group Editor with Alternative Communication Media in a Co-Authoring Environment

The writing efficiency of a type of computer-based groupware called a group editor was evaluated in six environments by factorially combining three communication media (audio only, audio plus video, and face-to-face) each with and without the group editor. Twelve subjects familiar with journalistic writing were pretested and matched into dyads. Subjects were trained with the group editor and wrote news articles based on a standard set of questions about actors and objects shown in short video clips. The quality of the writing task products was consistently high and showed no differences among conditions. Results of a balanced, within-subject analysis of variance design indicated that face-to-face conditions took significantly less time to complete than the other two communication conditions. When the group editor was used, however, all communication media were equal in terms of efficiency to face-to-face communications. Significantly less variance occurred in the audio plus video condition with the group editor than in the audio or the audio plus video conditions which did not have the group editor. Users preferred co-authoring with the group editor and considered writing trials with the group editor to be more productive. The results were discussed in terms of the benefits of using the group editor to increase the overall communication structure, to reduce variability of writing time among dyads, and to increase efficiency when face-to-face communication is not practical. Methodological procedures for matching subjects, using within-subject designs, and structuring a writing task were discussed as means of reducing team variability in writing efficiency when investigating computer-supported, cooperative work configurations.