Herschel W. Leibowitz, D. Alfred Owens, and , Robert L. Helmreich
The transportation field comprises vehicles ranging from submarines to spacecraft and technologies that span the iron age and the computer age. Human factors issues are important because individuals must interact with the large, complex systems of modern forms of transportation. Safety is critical, as most citizens utilize several modes of transportation, and transportation disasters are highly publicized. Investigations of transportation mishaps typically invoke contributory human factors issues, thus enhancing research opportunities.
The range of areas within transportation illustrates the expanded definition and role of human factors research. Traditional ergonomic issues clearly inform the design of vehicles and transportation systems. Operationally relevant human factors research encompasses cognitive, perceptual, and engineering psychology, as well as organizational, social, personality, educational, and cross-cultural disciplines. Levels of analysis range from the individual to the group to the organization to the culture; many research questions cut across disciplinary boundaries and demand a multidisciplinary approach.
Rather than document the full array of transportation research questions, we will focus on opportunities for behavioral research in two areas representative of the broad scope of human factors: vehicular traffic safety and aviation safety. In the first area, we discuss traditional concerns with
the individual and the machine, while in the second we describe the role of team performance and training in a high-technology environment. The human factors research relevant to aviation includes organizational, social and personality, educational, and cross-cultural psychology—as well as the more traditional cognitive, experimental, and engineering concerns. Many of the research issues raised here are not limited to vehicular and air domains, but apply in whole or part to other domains of transportation, including maritime and rail operations and space flight.
VEHICULAR TRAFFIC SAFETY
In dealing with traffic safety, the human factors community has the opportunity to contribute to the solution of a major public health problem. In the United States, motor vehicle accidents are the leading cause of death for people between the ages of 1 and 38 and are responsible for more deaths than all other causes combined between the ages of 15 and 24 (National Safety Council, 1993). Currently 1.7 million disabling injuries and 43,000 fatalities occur annually. Because traffic accidents take a disproportionate toll on the younger population, the average number of years of life lost per death is 2 and 3 times higher than for cancer and heart disease, respectively, and the mortality cost per death is 3.7 and 6.2 times higher.
On the basis of mortality costs, Sivak (1993) has estimated that the United States invests 15 times more heavily in research on cardiovascular disease and nearly 24 times more for cancer. Perhaps this discrepancy in expenditures occurs because traditionally traffic safety has been viewed—along with other issues of transportation—as a matter of commerce and technology. Certainly, our modern transportation systems exemplify the great benefits of technology for commerce. However, they also have major consequences for public health and welfare; these consequences arise not from the machinery per se but from the interaction of human users and technological systems. It is at this interface that human factors research comes into play.
A central requirement for progress in this area is the development of a coherent theoretical framework for addressing the task of driving. We must develop a theory of driving behavior that is both empirically grounded and ecologically valid. Present theoretical frameworks often consist of commonsense judgments (e.g., ''speed kills") or abstract flow charts that have only limited empirical support. One approach to traffic safety that is rapidly gaining attention is the attempt to use computational technology. This is based on the assumption that because computers are faster and more reliable than humans, they can eliminate or reduce costly human errors. Designing systems to assist or automate driving is a fascinating challenge and may ultimately
justify the investment of massive resources (Green and Brand, 1992). However, the successful development of such systems requires a fuller understanding of the fundamental characteristics of driving (Owens et al., 1993).
Researchers seeking a useful understanding of proficient driving and traffic safety skills should pursue multiple levels of conceptualization. They must address the regulatory difficulties that have persisted in licensing, training, and evaluating drivers as well as the problems associated with new technological systems. Many of these issues are widely recognized and repeatedly investigated, but systematic analyses are lacking. It is doubtful that useful general theories will follow from a focus on specific regulatory questions or from basic research on isolated or narrowly defined aspects of human performance. Rather, progress in understanding driving behavior will require coordination and integration of work at multiple levels of analysis, ranging from assessment of individual performance through specification of broad behavioral and informational requirements of the driving task to social aspects of communication among motorists in a changing traffic environment.
The theoretical requirements are challenging, and they offer exciting opportunities for gaining basic insights into human behavior in complex systems. The resulting agenda, however, should not be purely theoretical. Indeed, theory can receive an invaluable impetus from systematic attention to immediate practical problems. If investigators of current problems aim from the start to integrate their findings into a larger account of proficient driving performance in a complex traffic environment, their research will be doubly fruitful.
Screening and Licensing
Licensing examinations are universally administered. In the United States, they are typically based on an in-vehicle road test, a visual examination, and a series of questions testing the applicant's knowledge of driving regulations. The central problem with driver licensing is the poor predictive power of current test procedures. This issue is gaining in importance as a consequence of the 1990 Americans With Disabilities Act, which requires that exclusionary regulations be justifiable. We need to base licensing decisions on valid predictors of safe driving. Several states have already begun to relax visual acuity requirements as part of graduated licensing programs. Human factors research will be critically important in paving the way to valid and fair licensing procedures. At the same time, development of more reliable and efficient test procedures can contribute to the development of a comprehensive theory of driving.
In-Vehicle Testing and the Possible Benefits of Simulation
The current driving test typically evaluates the ability to negotiate a vehicle at low speeds on a specially constructed test track involving numerous turns and traffic signals. Such tests rarely, if ever, involve conditions under which accidents are most likely to occur, for example, under long-term demands, high speeds, competition for attention, emergencies, nighttime, or adverse weather driving conditions. If candidates for a driving license are to be tested under more realistic conditions, the method of choice is a driving simulator (McKnight and Stewart, 1990). Simulators are still expensive so they will probably be used only in selected cases. This situation appears to be changing, however, as increasingly sophisticated video and computing systems emerge at dramatically reduced costs. Such simulators may offer the most practical method to evaluate drivers under conditions that correspond more closely to those encountered in the driving environment. Although driving simulators have been available for many years, few are interactive, that is, with the visual environment changing to conform with vehicle movements. Interactive displays are the rule in aviation simulators, but making them available for driving simulation will require the development of less expensive display equipment.
A major problem in all simulators is the coordination of visual and vestibular simulation. A moving vehicle stimulates the vestibular system. In a fixed-base simulator, however, only the visual component of motion is available; the resulting mismatch between the visual and vestibular (and to a lesser extent proprioceptive) systems can induce nausea. This phenomenon, simulator sickness, has been of interest in aviation, but primarily for simulations of high-performance aircraft. Simulator sickness sometimes causes complex symptoms similar to motion sickness and has been reported to produce disorientation inside and outside the simulator. It is not yet clear how great a problem this will be for driving simulators; this must be evaluated as test simulators are developed. One possible solution is to impart motion to the operator (moving base simulator), but this would entail considerable additional expense.
Current computational technology is proceeding at a dazzling pace and it is not unreasonable to entertain the possibility of having driving simulators with realistic interactive displays and at a reasonable cost in the not-distant future.
It is often said that the driving task is 90 percent visual. While the original source of this proposition is obscure, most would agree that good vision is necessary. The problem is that we do not yet know what good
vision means in the context of driving. The conventional standard, which calls for a corrected visual acuity of 20/40, is not empirically justified and may be virtually irrelevant. The ineffectiveness of present visual testing procedures was dramatically demonstrated by Burg (1967, 1968, 1971), who correlated the results of both standard and nonstandard visual tests with the frequency of accidents for 17,000 drivers. Of all the tests employed, only dynamic visual acuity, a test not included (to our knowledge) in any licensing procedure currently in use in the United States, correlated with accidents, and even there the correlation was weak.
The basis for this low predictive power is probably related to the discrepancy between visual demands encountered during testing and those encountered while driving. Visual acuity tests evaluate only the threshold of resolution for high-contrast optotypes, that is, the ability to read fine print in bright illumination. Such tests have proven to be valuable for prescribing reading glasses. However, driving usually depends on large fields of relatively coarse visual structure, and it frequently requires recognizing low-contrast objects under low (mesopic) illumination. Therefore, it should not be surprising that research shows little or no correlation between standard acuity tests and accidents.
There is, however, a growing body of literature, both empirical and theoretical, suggesting that tests of peripheral vision, contrast sensitivity, and motion perception may be more useful. Johnson and Keltner (1983) obtained visual fields on 10,000 eyes and determined that individuals with binocular scotomas were more likely to be involved in accidents. Testing of visual fields on a large scale will require the development of automated perimetric devices. This area is being actively investigated, not because visual fields are critical for driving but because visual field examinations can detect early visual pathology.
Another promising approach is to assess vision for moving targets. Burg (1971) found that dynamic acuity, which requires the observer to resolve a moving optotype, was the only subtest related to accidents. Because motion is pervasive outside the laboratory, both the driver and the stimuli of interest are moving. The introduction of a gaze stability requirement for licensure is a logical step toward greater ecological validity.
One should also note that most critical visual stimuli encountered during driving have low luminance contrast. During the past several decades, the vision community has accumulated impressive evidence that contrast sensitivity is more informative than visual acuity for high-contrast optotypes, especially in predicting performance for visual tasks other than reading. For example, an observer with incipient cataracts can demonstrate normal acuity even though his or her ability to recognize low-contrast objects has been severely impaired. Several inexpensive contrast-sensitivity tests are now available.
In view of the poor predictive ability of the static optotypes now being used in visual testing, and the empirical and theoretical evidence for the importance of both a contrast-sensitivity criterion and motion, the development of a contrast-sensitive test of dynamic spatial vision is both wanted and wanting.
Perhaps the most significant concomitant of normal aging is the loss of ability to receive light. With age the pupil of the eye becomes progressively smaller. Typically, the maximum pupil diameter changes from 8 mm in youth to 4 mm in old age, a fourfold reduction in pupil area and, therefore, in light transmission. In addition, with increasing age, the optical media gradually become less transparent. On the average, the effective light transmitted to the retina is reduced by a factor of 2 every 15 years. Since the accident rate per mile driven is approximately 3.5 times higher at night than during the day, some test of nighttime vision is clearly to be recommended.
Despite these facts, and despite the extensive literature and instrumentation on night vision (developed primarily during World War II), to our knowledge no tests of night vision are currently in use, and, except for student drivers, there is no proscription for driving at night. What is needed is a test of nighttime vision that can be shown to be related to driving performance under low illumination levels. Whether this should evaluate recognition vision, visual guidance, or both is an empirical question. On the basis of information currently available, it would appear reasonable to restrict night driving for some individuals. Such graduated licensing regulations will require that reliable and valid testing procedures be developed.
The possibility of innovative tests of driving proficiency should also be considered. Based on the pioneering work of Gibson (1950, 1966, 1968), it has recently been suggested that the ability to guide a vehicle based on optical flow is critical in driving (e.g., Warren et al., 1991; Royden et al., 1992; Crowell and Banks, 1993). With the low-cost computers and displays available, such tests, if they demonstrate predictive power, are now feasible. Other visual abilities that might be considered include distance perception, ability to judge closing rates, glare sensitivity, velocity perception, and the ability to handle divided attention. The low predictive power of present procedures is a cogent argument for utilizing the wealth of information already available about vision and vision tests to develop new and better procedures.
Alcohol is universally recognized as a major contributor to traffic accidents (Shinar, 1978). It has been estimated that approximately 50 percent of automobile accidents involve alcohol (Evans, 1991). Depending on state driving laws, the critical level of blood alcohol, above which the driver is
assumed to be legally intoxicated, is on the order of 0.08 or 0.10 mg per 100 mg. However, the behavioral data do not support a fixed blood-alcohol criterion as a threshold of impairment. There is extensive evidence that many individuals are impaired at blood-alcohol levels that are half the values being used (Moskowitz, 1985). In addition, the limited performance data available demonstrate strikingly high intersubject variability (Wilson and Plomin, 1985). Some people with blood-alcohol levels below the current legal limits frequently perform less well on dynamic contrast sensitivity tests than others whose levels would classify them as legally intoxicated (Andre et al., 1992). Data are urgently needed to resolve this dilemma. If there is a blood-alcohol level that does not impair performance, it must be supported by performance data. Alternatively, the combination of drinking and driving should be prohibited and the legal limit set at the measurement error of the evaluation procedure.
Attention and Automaticity
A major problem in human performance is vigilance, that is, the need to remain alert during a repetitive task that induces drowsiness and lack of attention. The deficit may be general or may involve a narrowing of the effective field of attention. There are marked individual differences in the "useful field of view" (UFOV); these are correlated with accident records and, therefore, have significant implications for driving proficiency (Ball and Owsley, 1992). Recent studies indicate that restriction of the field of attention or UFOV poses a serious problem for older drivers. This important finding raises several research questions about how drivers allocate attention. What are the effects of fatigue, expectation, traffic demands, experience, and age? To what extent or in what mode is the UFOV test related to specific components of the driving task (Ball et al., 1993)? The relationship of the UFOV test to driving performance provides yet another example of the need for theoretical development. Much needs to be learned about the relevant attentional and automatic processes in driving.
Lack of alertness seems to be an obvious factor in transportation safety. Depending upon the state of the driver, reaction times can vary from less than 1 second to 2.5 seconds or more (e.g., Summala, 1981; Triggs and Harris, 1982). Unfortunately, it is difficult for drivers to monitor their own state of alertness, particularly during prolonged driving. A system that would inform drivers of waning alertness would be extremely valuable.
Training New Drivers
Understanding the skills involved in driving will provide insights about how these skills are acquired. The effectiveness of current driver training is
problematic, and it is important to learn better ways of teaching the skills involved in driving.
We suspect that the basic problem stems from the hierarchical nature of the driving task. The operational component—starting, steering, and stopping a vehicle—is relatively easy to learn and, once it has been learned, gives the novice driver the feeling of being in control. New drivers can also learn much of the "knowledge" (i.e., rules of the road) in a short time. Indeed, such rule-based knowledge is strongly emphasized in most driver tests. However, the driving task involves much more than vehicle control and familiarity with rules: for example, perceiving and anticipating the actions of other motorists and the potential of other roadway hazards. The identification and teaching of such abilities should be the focus of research.
We suggested above that the fundamental skills involved in driving are easy to acquire and that accidents may arise from failure to perceive and compensate for risk. In effect, the driver is aware of the danger and has the ability to take the necessary precautions but does not always anticipate or recognize the relevant hazards (Leibowitz and Owens, 1986). The higher accident rate among young drivers and the effects of alcohol, which typically increase risk-taking behavior, are consistent with this observation. Wilde (1988) has proposed that drivers adjust their risk level so as to compensate for engineering innovations in driver safety such as seat belts (risk homeostasis). In recent years, there has been an increase in the research literature devoted to risk-taking behavior, and its application to driving is clearly indicated (Wagenaar, 1992).
In contrast to the extensive research in aviation, relatively little attention has been given to displays for vehicles. It has been suggested that displays that convey information to the driver—such as stopping distance, momentum, and distance to road obstructions—would be useful. It has also been proposed that display information be optically superimposed on the road ahead so as to reduce the need for scanning the instrument panel (Weihrauch et al., 1989; Okabayashi et al., 1989). ("Heads-up" displays are now common in military aircraft.) Such proposals should be empirically tested. An adequate theory of driving will help specify the types of information that are most useful for safe driving. It will also help determine when the information is useful and what format of presentation (display design) is most effective (Weintraub and Ensing, 1992).
A common thread relevant to all of these problems is the effect of age on driving skills (Barr and Eberhard, 1991; Eberhard and Barr, 1992). It is well known that some major abilities relevant to driving—such as night vision, smooth pursuit eye movements, and reaction time—all decline systematically with age and that the elderly frequently experience difficulty with cluttered environments. It is also well established that individual differences in aging are pronounced and that age per se is not an unequivocal predictor of performance. Furthermore, to a great extent, the aging driver probably compensates behaviorally for perceptual and cognitive deficiencies, thus minimizing or delaying costs to safety.
Given the increasing longevity of our population and the central role of mobility as a factor in the quality of life, research in this area is particularly critical (Waller, 1991). Again, we see the need for a comprehensive theory of driving behavior that will enable clearer delineation of the specific skills and situations in which older drivers are most likely to face difficulties. As we noted earlier, we already have valuable information about some age-related changes (e.g., night vision and the UFOV), but we do not clearly understand the impact of such changes on safe driving (e.g., to what extent the older driver can or does compensate). In order to evaluate the capabilities of elderly drivers and provide appropriate advice and restrictions, we need a scientific foundation for graduated licensing criteria. In effect, for all of the categories mentioned above, special attention should be given to the role of aging.
Intelligent Vehicle Highway
Efforts are currently being directed toward the application of sophisticated control systems that would take over some of the driver's responsibilities. For example, the difficulty of estimating distance and velocity is assumed to account for the frequency of accidents involving a vehicle turning left in the face of oncoming traffic. To prevent such errors, it has been proposed that each vehicle be equipped with a system that senses how far the vehicle is from other vehicles and that informs the driver when it is unsafe to attempt a left turn. Assuming such systems are technically feasible, the critical question is whether drivers accustomed to observation outside the vehicle would divert their eyes from the road in order to obtain information from a display. The application of sophisticated information systems assumes that the driver will be willing to trust and act on such information. Solving these problems will require extensive human engineering testing to determine the optimum method of presenting the information,
for example, heads-up displays and auditory warnings. The human factors community has had extensive experience with similar problems in aviation, but they are by no means resolved. For example, ground proximity warning systems provide urgent auditory warning of impending flight into terrain, but in many instances, crews have disregarded the warning and have flown into the ground. It is critical that human factors analysis be incorporated in these programs (Weintraub and Ensing, 1992; Ervin, 1993; Owens et al., 1993).
A potentially fruitful area for research is the interaction between the law and transportation. Specifically, many laws require operators of vehicles to accomplish tasks that are not within their capabilities. This leads to unnecessary litigation and appellate reviews and creates a disrespect for laws. If statutes such as the Assured Clear Distance Ahead rule and regulations governing the use of alcohol were examined in relation to the behavioral sciences literature on human capabilities and limitations while operating a vehicle, the findings could lead to more rational laws and codes (Leibowitz et al., submitted for publication). Efforts directed at this problem represent a potentially valuable contribution.
The automobile plays a critical role in the quality of life in the United States as well as in other technologically advanced countries. Without the mobility it provides, the lives of many millions would be severely degraded. For this reason, legislatures have been reluctant to impose restrictions on driving licenses. From the data presently available, it is not readily apparent whether the unprecedented costs in human suffering and economic loss that our society tolerates as the price of mobility are justifiable. However, there is no doubt that measures to reduce this burden—whether they involve training, engineering innovations, alternative sources of transportation, or licensing restrictions—must be based on behavioral data.
TEAM PERFORMANCE AND AVIATION SAFETY
In stark contrast with automobile travel, commercial aviation is the safest form of mass transportation. Traditional ergonomics has played a substantial role in the development of all modern transport aircraft and remains an integral part of the design process (Wiener and Nagel, 1988). Commercial aviation remains one of the few vocations in which retirement at a fixed age is still required. Thus, age-related accidents are not a current
problem, and, similarly, little evidence has been found to suggest that alcohol and drugs pose major safety problems. (These problems do exist, however, in general aviation.)
Despite the focus on human factors in aviation, more than two-thirds of those accidents and incidents that do occur in the system include human error/human factors as causal elements (Lautman and Gallimore, 1987; Cooper et al., 1980). Although the total number of casualties is small relative to those produced by the automobile, aviation accidents are highly visible and elicit strong demands for action. The aviation community has responded to these data with both research and training addressing the human factors identified in accidents and incidents. These activities reflect a broader conception of human factors as it intersects social, personality, and organizational psychology. The results of these interventions, occurring worldwide and known generically as cockpit or crew resource management (CRM) training, represent one of the success stories of applied psychology and human factors. The programs have been shown to produce significant changes in the behavior and attitudes of flight crews and have been identified as preventing or mitigating serious accidents in both civil and military aviation (Diehl, 1991; Helmreich and Foushee, 1993; Helmreich and Wilhelm, 1991; Wiener et al., 1993). Despite the progress that has been made in CRM, a number of major research questions remain. In the following sections, we describe the CRM approach to aviation human factors and the open issues requiring research and committed action.
Human Factors Training Approaches
Flight crews operate within a system in which the individual functions as part of a team that functions within an organization that, in turn, is embedded in a regulatory and ambient environment. All components of the system influence group dynamics and the outcomes of a particular flight. As with many aspects of driver training, it is not clear that all relevant and needed training is provided or that the most appropriate aspects of performance are being evaluated. The Federal Aviation Administration defines pilot training specifications in the United States; these include extensive training in emergency procedures and technical maneuvers, many of which are seldom encountered in operational flight. Historically a single-pilot mentality has prevailed in regulation, which has ignored the need to perform effectively the team tasks that are required to pilot a modern transport in complex air space. For example, to maintain licensure, air transport pilots must currently undergo a proficiency check that focuses on individual technical expertise as demonstrated by execution of fixed maneuvers.
CRM training has evolved into a systematic approach to group communications, team coordination, leadership, decision making, and conflict resolution.
Effective training is based on diagnosis of organizational norms and problems, organizational restructuring (where needed), and experiential training that focuses on the development of specific behavioral skills (Federal Aviation Administration, 1993; Byrnes and Black, 1993; Taggart, 1994). Also integral to this approach is continuing (recurrent) training and reinforcement of effective behaviors, usually through the use of structured simulation (Butler, 1993). The critical difference between CRM training in aviation is the focus on the group rather than the individual as the unit of behavior and evaluation.
Research Needs in Aviation and Team Performance
Integrating Technical and Psychological Training
Although CRM training for flight crews has shown demonstrable, positive effects, it has not been successfully integrated with traditional technical instruction. The value of integrated instruction for complex technical operations—so that, for example, training in maintaining control after losing an engine on takeoff is integrated with training in the coordination, communication, and decision making required to deal with such a contingency—is widely recognized, and recently implemented Federal Aviation regulations will require such integration (Federal Aviation Administration, 1990; Helmreich and Foushee, 1993). The accomplishment of this goal, however, will provide a continuing challenge for human factors specialists.
A larger challenge will be found in the integration of human factors concepts with initial pilot training. To date, the emphasis has been on adding human relations skills to the repertoires of already qualified pilots, a process that often requires unlearning old behaviors and changing traditional practices. While the International Civil Aviation Organization, the component of the United Nations that regulates worldwide civil aviation, has introduced a requirement for human factors training as a condition of licensure, this does not equate to demonstrating and evaluating the human factors aspects of primary flight activities. A fully integrated curriculum that stresses interpersonal, as well as individual, skills from the outset should result in better-prepared pilots.
Understanding the Impact of Culture on Team Performance
One finding that emerged from research into the effectiveness of CRM training was the existence of differential reactions to training in different organizational and national settings (Helmreich and Foushee, 1993; Helmreich and Wilhelm, 1991). Many of the differences could be traced to the particular views that organizational cultures and subcultures held regarding
appropriate roles and behaviors. In addition, comparative data on the impact of CRM training from various national cultures are in accord with Hofstede's (1980, 1991) conceptualization of the dimensions of national culture, particularly differences in individualism/collectivism and in attitudes toward authority defined as power distance (Merritt and Helmreich, in press). For example, a training emphasis on the importance of the group and its maintenance is highly congruent with values in collectivist cultures, such as many South American and Asian nations, but less readily acceptable in more individualistic societies, such as the United States and Ireland. Similarly, an approach that stresses reducing status differentials between leaders and team members and the need for juniors to question the actions and decisions of leaders when they threaten safety is compatible with U.S. and Australian notions of egalitarianism, but mystifying to those from cultures, such as China and Malaysia, that rank high on Hofstede's power distance dimension in the reluctance of subordinates to question the actions of leaders. CRM training has not been successfully exported from one culture to another without consideration of differing values; this shows the importance of cultural issues even for supposedly standardized tasks, such as managing the flight of a transport aircraft. One challenge for human factors is to understand how cultures, both national and organizational, influence attitudes and behaviors related to safety and efficiency and to adapt training to reflect cultural issues. It should be of great concern to the manufacturers of aircraft that are marketed throughout the world.
Optimizing Curricula and Instructional Methods
Related to the influence of culture on attitudes and receptivity to instruction is a need to more precisely define which issues need to be stressed in human factors training and how best to deliver instruction. In general, human factors specialists have concluded from experience that curricula need to have high levels of specificity, to avoid overreliance on psychological concepts and jargon, and to be experiential rather than didactic. Even in this area, however, cultural values may influence responsiveness. Cultures that place a high value on instruction by authority figures may be less receptive to group discussion and more favorably influenced by more authoritative presentations. Overall, the goal for human factors is to define curricula that are relevant, are understandable, and can be presented in a way that can be understood in the context of individual values.
Improving the Evaluation of Group and System Performance
It is axiomatic that behavior cannot be successfully taught unless instances of the desired behavior are reinforced and that reinforcement cannot
occur unless the behavior can be precisely evaluated. Although the evaluation of individual technical performance in aviation has a long and successful history, this focus has stifled concern with developing more sophisticated approaches to the evaluation of group behavior and performance. Early attempts to improve group-level evaluation in aviation illustrated the difficulties of such assessments and the reluctance of operational personnel to expand the scope of evaluation (Gregorich and Wilhelm, 1993; Butler, 1993; Taggart, 1994). A more reliable and valid methodology for assessment of group-level phenomena should be widely beneficial, not only in aviation but also in other endeavors involving group-level tasks.
Also needed are improved methodologies for analyzing and understanding human error at the group and system levels. The study of complex determinants of error in technological environments has advanced significantly in recent years (Perrow, 1984; Rasmussen, 1993; Reason, 1990). Detailed analyses of aircraft accidents, in which pilot error is clearly the proximal cause, typically uncover an array of contributing factors that influenced the decision making and group dynamics on the flight deck. For example, the crash of a Canadian airliner on takeoff during a snowstorm resulted from the crew's flawed decision to take off with ice contaminating the wings. However, the findings of a commission of inquiry that investigated all aspects of the aviation system isolated a number of contributing factors at the regulatory, organizational, and group levels that created an environment with inadequate safeguards against a fatal decision (Helmreich, 1992; Moshansky, 1992). A taxonomy of human factors problems that can be applied to the analysis of accidents and incidents would be invaluable for researchers and for those charged with safety (Jones, 1993).
Automation and the ''Electronic" Crew Member
As increasingly sophisticated computer systems characterize the flight decks of modern aircraft, crews face the new dilemma of how to integrate an "electronic" crew member into team operations. When many activities are shifted from human to computer control, issues of maintaining competencies, vigilance, and awareness arise, and shifts may occur in the dynamics of crew interaction. Defining a coherent, research-based philosophy of automation is a critical task that involves human factors experts participating in the design and manufacture of aircraft as well as in the organizations that operate them (Billings, 1989; Wiener, 1993). The philosophy of automation needs to address what should be automated as well as how automation should be accomplished. The principle that what can be automated should be automated has not demonstrated marked success in reducing human error or workload, but has resulted in enormous capital expenditures. An excellent discussion of issues of automation design is found in the report
of an extensive investigation of the fatal flight into terrain of a highly automated aircraft in 1992 (Ministère de L'Équipement, des Transportes, et du Tourisme, 1993). A philosophy of automation also needs to address the use of automated systems: when they should be used and when control should revert to the human operator. At the user level, this needs to be incorporated into training and organizational norms.
Recent research suggests that there are large cultural differences in attitudes regarding the acceptance and use of automated systems, including, for example, willingness to disengage automated systems and revert to human control when conditions change (e.g., Sherman and Law, 1994). Human factors specialists and airframe manufacturers must recognize that human-computer interfaces are highly varied and culturally determined; they can then undertake research to define these differences and training strategies to deal with them.
Advanced technology aircraft are now operated with a crew of two pilots. However, crews are augmented with relief pilots for extremely long intercontinental flights. Extended routine cruising raises questions of maintaining proficiency, combatting fatigue and complacency, and transferring control among extended crews. Many of these issues have not been systematically addressed in research.
Dealing with Training Failures
The success of human factors training in aviation is diminished to some extent by the fact that the concepts and behaviors taught are not universally accepted, even within a particular organization or culture. In all programs evaluated, a small subset of individuals fails to respond positively to training efforts, and some may even become less accepting of and more resistant to team coordination (Chidester et al., 1990a, 1990b; Helmreich and Wilhelm, 1989, 1991). These failures in training are necessarily of concern because those who actively reject strategies to enhance performance are likely to pose the greatest threat to safety. One source of resistance may lie in personality characteristics of those who react negatively. For example, Chidester et al. (1990a, 1990b) found that those lacking in attributes associated with effective interpersonal behavior were more prone to reject training that stressed the importance of interpersonal communication. Given the unlikelihood of effecting basic changes in personality except by extended psychotherapy, improved selection in terms of performance-related personality traits may be the last line of defense against ineffective crew coordination and teamwork. However, the human factors community should exhaust all avenues of research to determine if there are means of remediation for those deficient in interpersonal communication skills.
Extending the Concepts Beyond the Cockpit Door
Human factors research in aviation has grown from its original focus on enhancing communication and coordination among the basic flight team into an awareness that many of the problems in the system reside in interfaces between teams and other components of the aviation system, including, for example, air traffic control and ground operations (Taggart, 1993, 1994). New strategies and associated research will be required to develop and validate training methodologies that effectively address intergroup as well as intragroup coordination and cooperation.
EXTENDING HUMAN FACTORS TRAINING INTO OTHER DOMAINS
It is becoming clear that the human factors approaches encompassed by CRM in aviation apply more generally to endeavors in which teams function with technology under demanding conditions (Helmreich et al., 1993). For some years, the National Transportation Safety Board (NTSB) has been advocating the extension of CRM from the cockpit to the bridge of maritime vessels (e.g., National Transportation Safety Board, 1993). More recently, the medical profession has noted similarities in human factors problems in the operating room and in the cockpit and has begun to adapt training and evaluation strategies from aviation (Ewell and Adams, 1993; Howard et al., 1992; Helmreich and Schaefer, 1994). Similar issues should exist in control rooms of nuclear power plants, petrochemical operations, and other manufacturing enterprises (Helmreich et al., 1993). It is essential that the human factors community avoid trying to export training from one domain to another in a simplistic manner; the pitfalls of such an approach were discovered in attempts to move training across national boundaries. The characteristics and cultures of each domain must be investigated and understood before common concepts can be applied effectively.
A few examples may illustrate extensions of human factors concerns from aviation to seafaring. Although events play out at a much slower pace than in an automobile or aircraft, ships are operated by teams interacting with technology in a regulated environment. In the majority of marine disasters, as in aviation, human error is also implicated. Automation is also becoming a common shipboard characteristic, associated with large decreases in personnel and again raising issues of vigilance and reliance on computer solutions. Issues of national culture are also of great importance in maritime operations, and many ships are operated by multinational crews for
economic reasons. The traditional culture of the sea, in which the captain is the unchallenged (and frequently autocratic) master, can inhibit the effective communication and utilization of available resources, especially human ones. Team interface issues have also been implicated in a number of marine accidents, specifically flawed communications between pilots and masters while operating in restricted waters (e.g., National Transportation Safety Board, 1993).
As noted, the NTSB has concluded that many of these problems could be alleviated through effective human factors interventions and the adoption of approaches successfully employed in aviation. This will, however, require a substantial research endeavor to define common and divergent factors and to design human factors programs that will be accepted within the general maritime and specific organizational cultures involved.
The field of transportation provides rich opportunities to expand the scope of human factors in areas for which outcomes have major consequences. Optimizing the interface between individuals and groups with complex technology and systems requires a multidisciplinary approach that embraces the full range of concerns of human factors specialists. Concern with a particular problem, whether vehicular or aviation safety, should not blind researchers to concepts that transcend problem areas and that reflect more broadly on human capabilities and limitations. At the same time, research and solutions must be sensitive to the characteristics of the particular endeavor.
Andre, J.T., R.A. Tyrrell, M.E. Nicholson, M. Wang, and H.W. Leibowitz 1992 Measuring and predicting the effects of alcohol on contrast sensitivity for static and dynamic gratings. Investigative Ophthalmology and Visual Science (ARVO Abstract) 33(4):1416.
Ball, K., and C. Owsley 1992 The useful field of view: a new technique for evaluating age-related declines in visual function. Journal of the American Optometric Association 63:71-79.
Ball, K., C. Owsley, M. Sloan, D.L. Roenker, and J.R. Bruni 1993 Visual attention problems as a predictor of vehicle crashes among older drivers. Investigative Ophthalmology and Visual Science 34(11):3110-3123.
Barr, R.A., and J.W. Eberhard 1991 Safety and mobility of elderly drivers, Part I. Special Issue. Human Factors 33(5):497-603.
Billings, C.E. 1989 Toward a human centered aircraft automation philosophy. Pp. 1-8 in Proceedings of the Fifth International Symposium on Aviation Psychology . Columbus: Ohio State University.
Burg, A. 1967 The Relationship Between Vision Test Scores and Driving Record: General Findings. Department of Engineering Report No. 67-24. Los Angeles, Calif.: University of California. 1968 The Relationship Between Vision Test Scores and Driving Record: Additional Findings . Department of Engineering Report No. 68-27. Los Angeles, Calif.: University of California. 1971 Vision and driving: a report on research. Human Factors 13(1):79-87.
Butler, R.E. 1993 LOFT: full-mission simulation as crew resource management training. Pp. 231-259 in E. Wiener, B. Kanki, and R. Helmreich, eds., Crew Resource Management. San Diego, Calif.: Academic Press.
Byrnes, R.E., and R. Black 1993 Developing and implementing CRM programs: the delta experience. Pp. 421-443 in E. Wiener, B. Kanki, and R. Helmreich, eds., Crew Resource Management. San Diego, Calif.: Academic Press.
Chidester, T.R., R.L. Helmreich, S.E. Gregorich, and C.E. Geis 1990a Pilot personality and crew coordination: implications for training and selection. International Journal of Aviation Psychology 1:23-42.
Chidester, T.R., B.G. Kanki, H.C. Foushee, C.L. Dickinson, and S.V. Bowles 1990b Personality Factors in Flight Operations, Vol. 1. Leader Characteristics and Crew Performance in Full-Mission Air Transport Simulation. NASA Technical Memorandum No. 102259. Moffett-Field, Calif.: NASA-Ames Research Center.
Cooper, G.E., M.D. White, and J.K. Lauber, eds. 1980 Resource Management on the Flightdeck: Proceedings of a NASA/Industry Workshop. NASA CP-2120. Moffett Field, Calif.: NASA-Ames Research Center.
Crowell, J.A., and M.S. Banks 1993 Perceived heading with different retinal regions and types of optic flow. Perception and Psychophysics 53(3):325-337.
Diehl, A.E. 1991 The effectiveness of training programs for preventing aircrew "error." In Proceedings of the Sixth International Symposium of Aviation Psychology. Columbus: Ohio State University.
Eberhard, J.W., and R.A. Barr, eds. 1992 Safety and mobility of elderly drivers, Part II. Special Issue. Human Factors 34(1):1-65.
Ervin, R. 1993 Bringing Human Factors Expertise to the Conceptualization of Active-Safety Technology. Paper presented at the UMTRI Human Factors Festival. Ann Arbor: University of Michigan Transportation Research Institute.
Evans, L. 1991 Traffic Safety and the Drive. New York: Van Nostrand Reinhold.
Ewell, M.G., and R. Adams 1993 Aviation psychology, group dynamics and human performance issues in anesthesiology. Pp. 499-504 in Proceedings of the Seventh International Symposium on Aviation Psychology. Columbus: Ohio State University.
Federal Aviation Administration 1990 Advanced Qualification Program. Washington, D.C.: Federal Aviation Administration. 1993 Crew Resource Management Training. Advisory Circular AC 120-51A. Washington, D.C.: Federal Aviation Administration.
Gibson, J.J. 1950 The Perception of the Visual World. Boston, Mass.: Houghton Mifflin. 1966 The Senses Considered as Perceptual Systems. Prospect Heights, Ill.: Waveland Press. 1968 What gives rise to the perception of motion? Psychological Review 75:335-346.
Green, P., and J. Brand 1992 Future In-Car Information Systems: Input from Focus Groups. SAE Technical Paper No. 920614. Warrendale, Penn.: Society of Automotive Engineers.
Gregorich, S.E., and J.A. Wilhelm 1993 Crew resource management training assessment. Pp. 173-198 in E. Wiener, B. Kanki, and R. Helmreich, eds., Crew Resource Management . San Diego, Calif.: Academic Press.
Helmreich, R.L. 1992 Human factors aspects of the Air Ontario crash at Dryden, Ontario. In V.P. Moshansky, ed., Commission of Inquiry Into the Air Ontario Accident at Dryden, Ontario: Final Report. Ottawa, Ontario: Minister of Supply and Services, Canada.
Helmreich, R.L., and H.C. Foushee 1993 Why crew resource management? Empirical and theoretical bases of human factors training in aviation. In E.L. Wiener, B.G. Kanki, and R.L. Helmreich, eds., Cockpit Resource Management. San Diego, Calif.: Academic Press.
Helmreich, R.L., and H.-G. Schaefer 1994 Team performance in the operating room. Pp. 225-254 in M.S. Bogner, ed., Human Error in Medicine. Hillsdale, N.J.: Erlbaum.
Helmreich, R.L., and J.A. Wilhelm 1989 When training boomerangs: negative outcomes associated with cockpit resource management programs. In R.S. Jensen, ed., Proceedings of the Fifth International Symposium on Aviation Psychology. Columbus: Ohio State University. 1991 Outcomes of crew resource management training. International Journal of Aviation Psychology 1(4):287-300.
Helmreich, R.L., E. Wiener, and B.G. Kanki 1993 The future of crew resource management in the cockpit and elsewhere. Pp. 479-501 in E. Wiener, B. Kanki, and R. Helmreich, eds., Crew Resource Management. San Diego, Calif.: Academic Press.
Hofstede, G. 1980 Culture's Consequences: International Differences in Work-Related Values. Beverly Hills, Calif.: Sage. 1991 Cultures and Organizations: Software of the Mind. Maidenhead, England: McGraw-Hill.
Howard, S.K., D.M. Gaba, K.J. Fish, G. Yang, and F.H. Sarnquist 1992 Anesthesia crisis resource management: teaching anesthesiologists to handle critical incidents. Aviation, Space, and Environmental Medicine 63:763-770.
Johnson, C.A., and J.L. Keltner 1983 Incidence of visual field loss and its relation to driving performance. Archives of Ophthalmology 101:371-375.
Jones, S.G. 1993 Human factors in incident reporting. Pp. 567-572 in Proceedings of the Seventh International Symposium on Aviation Psychology. Columbus: Ohio State University.
Lautman, L.G., and P.L. Gallimore 1987 Control of the crew-caused accident. Airliner Magazine, April-June:1-7. Seattle, Wash.: Boeing Commercial Airplane.
Leibowitz, H.W., and D.A. Owens 1986 We drive by night. Psychology Today 54-58.
Leibowitz, H.W., D.A. Owens, and R.A. Tyrrell The Assured Clear Distance Ahead Rule: Implications for Traffic Safety and the Law. (Submitted for Pulication)
McKnight, A.J., and M.A. Stewart 1990 Development of a Competency Based Driver License Testing System . Final Report for the California Department of Transportation. Landover, Md.: National Public Services Research Institute.
Merritt, A.C., and R.L. Helmreich In Press Human factors on the flight-deck: the influence of national culture. Journal of Cross-Cultural Psychology .
Ministère de L'Équipement, des Transportes, et du Tourisme 1993 Rapport de la Commission d'Enquête sur l'Accident Survenu le 20 Janvier 1992 Près du Mont Sainte Odile (Bas Rhin) a l'Airbus A.320 Immatricule F-GGED Exploité par la Compagnie Air Inter . Paris, France: Ministère de L'Équipement, des Transportes, et du Tourisme.
Moshansky, V.P. 1992 Commission of Inquiry Into the Air Ontario Accident at Dryden, Ontario: Final Report, Vols. 1-4. Ottawa, Ontario, Canada. Minister of Supply and Services.
Moskowitz, H., M.M. Burns, and A.F. Williams 1985 Skills performance at low blood alcohol levels. Journal of Studies on Alcohol 46(6):482-485.
National Safety Council 1993 Accident Facts, 1993 edition. Itasca, Ill.: National Safety Council.
National Transportation Safety Board 1993 Grounding of the UK passenger vessel RMS Queen Elizabeth 2 near Cuttyhunk Island, Vineyard Sound, Massachussetts. NTSB/MAR-93/01. Washington, D.C.: National Transportation Safety Board.
Okabayashi, S., M. Sakata, J. Fukano, S. Daidoji, C. Hashimoto, and T. Ishikawa 1989 Development of Practical Heads-Up Display for Production Vehicle Application. SAE Technical Paper Series No. 890559. Warrendale, Penn.: Society of Automotive Engineers.
Owens, D.A., G. Helmers, and M. Sivak 1993 Intelligent vehicle highway systems: a call for user-centered design. Ergonomics 36(4):363-369.
Perrow, C. 1984 Normal Accidents: Living With High Risk Technologies. New York: Basic Books.
Rasmussen, J. 1993 Deciding and doing: decision making in natural context. In G. Klein, J. Orasanu, R. Calderwood, and C. Zsambok, eds., Decision Making in Action: Models and Methods. Norwood, N.J.: Albex.
Reason, J. 1990 Human Error. Cambridge, England: Cambridge University Press.
Royden, C.S., M.S. Banks, and J.A. Crowell 1992 The perception of heading during eye movement. Nature 360:583-585.
Sherman, P.J., and J.R. Law 1994 Are there differences for standard vs. automated aircraft? Within-airline comparisons of aircraft types. Pp. 110-115 in Proceedings of the 14th Biennial Meeting of Applied Behavioral Sciences Symposium. Colorado Springs, Colo.: United States Air Force Academy.
Shinar, D. 1978 Psychology on the Road. New York: Wiley.
Sivak, M. 1993 Some Speculations About How to Determine Traffic-Safety Priorities. Unpublished presentation at the UMTRI Human Factors Festival, Ann Arbor, Michigan . University of Michigan Transportation Research Institute, March.
Summala, H. 1981 Driver/vehicle steering response latencies. Human Factors 23:683-692.
Taggart, W.R. 1993 How to kill off a good CRM program. The CRM Advocate 93(1):11-12. 1994 Crew resource management: achieving enhanced flight operations. In N. Johnston, N. McDonald, and R. Fuller, eds., Aviation Psychology in Practice. Brookfield, Vt.: Ashgate.
Triggs, T.J., and W.G. Harris 1982 Reaction time of drivers to road stimuli. Report No. 0-86746-1470 for Commonwealth Department of Transportation, Australian Office of Road Safety.
Wagenaar, A.C. 1992 Risk taking and accident causation. Pp. 257-281 in J.F. Yates, ed., Risk-Taking Behavior. New York: John Wiley & Sons.
Waller, P.F. 1991 The older driver. Human Factors 33(5):499-505.
Warren, W.H., Jr., D.R. Mestre, A.W. Blackwell, and M.W. Morris 1991 Perception of circular heading from optical flow. Journal of Experimental Psychology: Human Perception and Performance 17(1):28-43.
Weihrauch, M., T.C. Goesch, and G.G. Meloeny 1989 The First Head Up Display Introduced by General Motors. SAE Technical Paper No. 890288. Warrendale, Penn.: Society of Automotive Engineers.
Weintraub, D.J., and M. Ensing 1992 Human Factors Issues in Head-Up Displays: The Book of HUD. Wright-Patterson Air Force Base, Ohio: Crew Systems Ergonomics Information Center.
Wiener, E. 1993 Crew coordination and training in the advanced-technology cockpit. Pp. 199-230 in E. Wiener, B. Kanki, and R. Helmreich, eds., Crew Resource Management. San Diego, Calif.: Academic Press.
Wiener, E., B. Kanki, and R. Helmreich, eds. 1993 Crew Resource Management. San Diego, Calif.: Academic Press.
Wiener, E.L., and D.C. Nagel 1988 Human Factors in Aviation. San Diego, Calif.: Academic Press.
Wilde, G.J.S. 1988 Risk homeostasis theory and traffic accidents: propositions, deductions and discussion of dissension in recent reactions. Ergonomics 31(4):441-468.
Wilson, J.R., and R. Plomin 1985 Individual differences in sensitivity and tolerance to alcohol. Social Biology 32(3-4):162-184.