Posts Tagged Human Factors Engineering
Road hazard is any object, situation, occurrence or combination of these that introduce the possibility of the individual road user to experience harm (see Hawarth, Symmons & Kowadlo, 2000).
Hazard Perception (HP) is the ability to read the road (Mills, Hall, McDonald & Rolls, 1988) or situation awareness for dangerous situations (Horswill & Mckenna, 2004).
HP is a skill that improves with driving experience. Experienced drivers have a more holistic perception of the traffic environment. They adjust their eye scanning patterns to the characteristics of the traffic environment and they detect more hazards than young-inexperienced drivers. Young-inexperienced drivers (with few months of driving experience) have an impoverished knowledge base which causes them to pay more attention to unimportant details, and to scan the road less efficiently. With regard to elderly drivers, some studies have shown that unlike other driving-related skills, HP does not diminish over the years, since it is based on accumulated experience and schemata.
We used a video observation technique and showed that elderly drivers identified more hazards than experienced drivers, thereby supporting the claim that hazard perception does not diminish over time. However, in some cases they identify hazards later than experienced drivers. Thus, elderly drivers may identify the hazard (e.g., an intersection) at the same time as the experienced driver, but have slower physical reaction time or, more likely, project the hazards based on their own driving behavior which often consists of slower driving speeds than the obtained driving speed in the video-based scenarios.
To read more see our recent article: Age, skill, and hazard perception in driving Accident Analysis & Prevention, Volume 42, Issue 4, July 2010, Pages 1240-1249. Avinoam Borowsky, David Shinar, Tal Oron-Gilad
This study examined the effects of age and driving experience on the ability to detect hazards while driving; namely, hazard perception. Studies have shown that young-inexperienced drivers are more likely than experienced drivers to suffer from hazard perception deficiencies. However, it remains to be determined if this skill deteriorates with advancing age. Twenty-one young-inexperienced, 19 experienced, and 16 elderly drivers viewed six hazard perception movies while connected to an eye tracking system and were requested to identify hazardous situations. Four movies embedded planned, highly hazardous, situations and the rest were used as control. Generally, experienced and older-experienced drivers were equally proficient at hazard detection and detected potentially hazardous events (e.g., approaching an intersection, pedestrians on curb) continuously whereas young-inexperienced drivers stopped reporting on hazards that followed planned, highly hazardous situations. Moreover, while approaching T intersections older and experienced drivers fixated more towards the merging road on the right while young-inexperienced drivers fixated straight ahead, paying less attention to potential vehicles on the merging road. The study suggests that driving experience improves drivers’ awareness of potential hazards and guides drivers’ eye movements to locations that might embed potential risks. Furthermore, advanced age hardly affects older drivers’ ability to perceive hazards, and older drivers are at least partially aware of their age-related limitations.
Eye scanning patterns obtained from elderly-experienced (red), experienced (green) and young-inexperienced (blue) drivers are shown in the pictures below. The more experienced drivers tend to concentrate on the merging road on the right. Young drivers focus closer and more to the left.
Driving requires the driver to maintain high levels of alertness even with little or no interesting stimulation. As the driving route becomes more monotonous and familiar the driver is susceptible to loss of alertness and ‘passive’ fatigue symptoms (fatigue that develops over time when there appears to be little or no interesting stimulation).
This phenomenon is not unique to driving; here is what Commander James Edgar Waldron wrote about Flying:
“While much has been written about the glories and thrills of flying, it seems to me that too little has been stated about the boredom and tedium that drags on in between these fun-filled times. Although there is a saying that flying encompasses hours and hours of boredom, interspersed with occasional moments of terror, the tedium is seldom stressed. This chapter is not about terror, but about those long hours of sitting in a cockpit, as mile after mile of repetitious scenery sailed by. It is about the little things I would do to keep my interests from sagging and my eyelids from slamming shut”.
To counteract fatigue, drivers adopt different coping behaviors while driving; behaviors that they think (or hope) will maintain their alertness. Most common behaviors include listening to the radio, opening a window, following the separation line, talking to a passenger/on the phone, and drinking coffee. In research studies some of these behaviors were not proven to be effective in maintaining alertness. Little has been done in finding technological solutions to make the driver more alert (as opposed to alert the driver of his state).
In a simulator study among professional truck drivers, we examined whether using cognitive-demanding games (such as Trivia) helps in maintaining alertness in prolonged monotonous drives. Our study showed short-term effectiveness for the ‘Trivia’ AMT particularly in comparison with driving without countermeasures. Listening to music was also more beneficial than we expected.
You can read more about: Alertness maintaining tasks (AMTs) while driving, Accident Analysis & Prevention, Volume 40, Issue 3, May 2008, Pages 851-860, Tal Oron-Gilad, Adi Ronen, David Shinar
We evaluated the effectiveness of alertness maintaining tasks (AMTs) on driver performance, subjective feelings, and psychophysiological state in monotonous simulated driving in two experiments. In the first experiment, 12 professional truck drivers participated in five sessions of simulated driving: driving only, driving with one of three AMTs (counterbalanced), and driving while listening to music. AMTs were not equally effective in maintaining alertness. The trivia AMT prevented driving performance deterioration, and increased alertness (measured by standardized HRV). The choice reaction time AMT was least demanding but also increased subjective sleepiness and reduced arousal (measured by alpha/beta ratio). The working memory AMT caused a significant decrement in driving speed, increased subjective fatigue, and was regarded by the participants as detrimental to driving. Trivia was preferred by the majority of the drivers over the other two AMTs. Experiment 2 further examined the utility of the trivia AMT. When the drivers engaged in the trivia AMT they maintained better driving performance and perceived the driving duration as shorter than the control condition. The two experiments demonstrated that AMTs can have a positive effect on alertness. The effect is localized in the sense that it does not persist beyond the period of the AMT activation.
The Figure shows the Alertness Ratio (derived from the EEG) for a single driver. The local positive effect of the Trivia-AMT on alertness is apparent.
For those of you who are interested in the role of Human-Robot Interaction (HRI) in future military operations, Mike Barnes and Florian Jencth have recently edited a handbook titled “Human-Robot Interactions in Future Military Operations“. The book is a collection of chapters written by well recognized researchers in the area. It provides a wide range of topics from operators interacting with small ground robots and aerial vehicles to supervising large, near-autonomous vehicles capable of intelligent battlefield behaviors.
I was honored to contribute a chapter to this book. Together with my colleague and former student Yaniv Minkov we discuss the issue of “Remotely Operated Vehicles (ROVs) from the bottom-up operational perspective“.
Here is the abstract of one of my latest studies. It appears in a special issue of JCEDM “Improving Human-Robot Interaction in Complex Operational Environments: Translating Theory into Practice”
* Oron-Gilad, T., Redden, E.S. and Minkov, Y. (2011). Robotic Displays for Dismounted Warfighter Situation Awareness of Remote Locations: A field study, Journal of Cognitive Ergonomics and Decision Making. Accepted November 2010.Volume 5, Number 1, March 2011, pp. 29–54.
This study investigated scalability of unmanned vehicle displays for dismounted warfighters. Task performance, workload and preferences for three display devices were examined in two operational settings: tele-operation of an unmanned ground vehicle and intelligence gathering from a remote unmanned vehicle. Previous research has demonstrated variability in operational needs with regard to active tele-operation versus passive intelligence gathering. Thus, it was important to identify whether there was actually a dichotomy between the two in terms of screen space requirements and whether this difference stems from task differences or other factors. Thirty-one soldiers participated in a field study at Ft. Benning, GA. They were required to perform tele-operation and intelligence gathering tasks. Results reconfirmed our hypothesis that display type influences performance in intelligence-related tasks that require the use of video feed and digital map. No significant differences among display types were found in the UGV tele-operation task. In conclusion, dismounted warfighters can adequately perform both active and passive duties with a hand held device where the video window is as small as 4.3 inches in diameter. However, monocular HMDs for robotic displays can be problematic and should be carefully assessed before use in dismounted warfighters missions.