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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
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Publication Number: FHWA-RD-95-176
Date: November 1996
Development of Human Factors Guidelines for Advanced Traveler Information Systems and Commercial Vehicle Operations: Task Analysis of ATIS/CVO Functions
APPENDIX A. LITERATURE REVIEW
Allen, R.W., Stein, A.C., Rosenthal, T.J., Ziedman, D., Torres, J.F., & Halati, A. (1991). A human factors simulation investigation of driver route diversion and alternate route selection using in–vehicle navigation systems. In Vehicle Navigation and Information Systems Conference Proceedings (pp. 9–26). Dearborn, MI.
TOPIC: Decision making in diverting TYPE OF ARTICLE: Empirical study SUBJECT POPULATION: Automobile drivers, ages 18–29, 30–55, and > 55
This paper describes a human factors simulation study of the decision–making behavior of drivers attempting to avoid nonrecurring congestion by diverting to alternate routes with the aid of in–vehicle navigation systems. The object of the driver behavior experiment was to compare the effect of various experimental navigation systems on driver route diversion and alternate route selection. The experimental navigation system configurations included three map–based systems with varying amounts of situation information and a non–map–based route guidance system.
The overall study results indicated that navigation system characteristics can have a significant effect on driver diversion behavior, with better systems allowing more anticipation of traffic congestion. Subject route familiarity, commercial driving experience, and gender did not significantly affect the results. Alternate route analysis tended to confirm the main route diversion results and also showed that a majority of drivers were willing to accept alternate routes suggested by advanced navigation systems. Older drivers were more reluctant to divert from the main freeway route.
1. Independent variables
2. Dependent variables. Subject's willingness to choose alternate routes to avoid congestion.
3. Actual percentage of subjects who choose alternate routes.
4. Control conditions. Divided between commercial and non–commercial drivers, gender, and route familiarity.
5. Data analysis techniques. X2.
6. Methodology. Simulation on a personal computer that controlled visual and auditory displays simulating travel along a freeway. Rewards and penalties.
REVIEW OF ARTICLE
Somewhat useful. Data were obtained using a simulation rather than a real setting. Generally, the results suggest that subjects are influenced by in–vehicle navigation systems. However, these results could have been biased because of subjects' expectations. Experimenters failed to consider the fact that the alternate routes could become congested.
1. Various classes of navigation systems: Class 0 (open–loop systems) to Class 4 (dynamic closed–loop systems). Class 0 includes simple directional aids, map display systems, route guidance aids (e.g., ETAK); Class 4 contains two–way communication between vehicle and control center, centralized vehicle tracking, optimal routing, and information transfer (e.g., Ali–Scout and Autoguide).
2. Driver's ability to navigate through a complex environment depends on knowledge of the surroundings and available navigational aids; driver's performance depends on trip purpose and driver's goals.
3. Older subjects took longer to divert in response to congestion.
4. A lower percentage of the older age group diverted as compared to the younger and middle–age groups.
5. Route familiarity and commercial driving experience did not influence diversion decisions.
6. The advanced experimental and route guidance systems encouraged subjects to divert sooner in anticipation of congestion.
7. Of the route guidance and advanced experimental groups, 70 to 85 percent followed the alternate route recommendation.
8. There was some tendency for drivers to select the shortest possible alternate route regardless of In–Vehicle Navigation System (IVNS) recommendations.
Allen, T.M., Lunenfeld, H., & Alexander, G.J. (1971). Driver information needs. Highway Research Record, 366, pp. 102–115.
TOPIC: Driver information needs
The driving task was analyzed to determine the nature and interrelationship of the subtasks the driver performs and the information needed to perform them safely and efficiently. Data were developed using a modified information–decision–action task analysis method applied to several long driving trips. The task analysis provided the basis for categorizing the various component driving subtasks, identifying information needs associated with the subtasks and their present methods of satisfaction, and providing a structure to the driving task. Driving subtasks were categorized in accordance with information–decision–action complexity and ordered along a continuum. The subtasks were found to fall along a hierarchical scale. Vehicle control subtasks, such as steering and speed control, were ordered at the lowest level and identified as micro–performance (control). At an intermediate level, subtasks associated with response to road and traffic situations were identified as situational performance (guidance). The highest level subtasks, encompassing trip planning and preparation and route finding, were identified as macro–performance (navigation). Performance of subtasks at the highest level of the hierarchy involves component performance at a lower level. Drivers search the environment for information needed to perform the various subtasks and shift attention from one information source to another by a process of load–shedding. When load–shedding is required due to the demands of the driving situation encountered, information associated with subtasks relative to the subjective needs of the driver is attended to, and other information sources are shed.
Somewhat useful even though the article is dated. The article provides a model to identify the interrelationships between the various levels of performance activities that a driver must accomplish.
1. Driving task analysis procedure: Data were collected: (a) for each situation encountered in transit; (b) for each piece of information displayed; (c) on driver observations and expectancies relative to information needed; (d) to reflect road and traffic conditions; (e) on driver perception; (f) on driver cognition (evaluations, predictions, and decisions); (g) to show driver control responses; and (h) on feedback information.
2. Levels of performance
3. Attention: The hierarchy describes the load–shedding behavior of the driver. When the driver becomes overloaded by a subtask at one level of performance, he or she sheds all tasks higher, but not those lower. One way to avoid overloading is to apply the principle of spreading the tasks.
5. Expectancy: It is necessary to respect driver's expectancy to maintain safe driving. This need is the greatest at the situational level as well as at the macro–performance level.
6. Information needs
Barrow, K. (1991). Human factors issues surrounding the implementation of in–vehicle navigation and information systems. SAE Technical Paper Series (SAE No. 910870, pp. 1–15). Warrendale, PA: Society of Automotive Engineers.
TOPIC: Human factors in In–Vehicle Navigation Systems (IVNS)
Many questions surround the possible implementation of an advanced driver information system into passenger vehicles. The technology to relieve increasing traffic congestion problems exists today, but the methods to safely use this technology do not. There are many concerns in the government, industry, and academic communities surrounding the implementation of graphic display monitors inside passenger vehicles. This concern stems from recent studies on the effect of cellular phones, touch panels, and electronic navigational systems on driver attention demands.
These studies show that driver attention is taken from the roadway to operate these systems. However, more research into basic human/vehicle ergonomics needs to be conducted in order to determine how the demands of in–vehicle electronics affect highway safety. Recommendations include maintaining and broadening the scope of human factors research, continued use of field testing, the implementation of pre–production standards and regulations, increased driver education and training, and continuation of realistically engineered systems.
This paper consists of an extensive review of the: (1) various Intelligent Vehicle–Highway Systems (IVHS), and (2) current human factors literature regarding the Advanced Traveler Information System (ATIS).
1. Various functions of IVHS
2. Two types of driver information systems
3. Results from various studies
4. Design philosophy. Instead of controlling the amount of information, it is more desirable to control the characteristics of the display. It is better to specify a standard or regulation that indicates how much workload a display can place on a driver rather than a design standard that attempts to predict what that workload would be (e.g., number of items, size, shape, etc.).
Coury, B.G., Weiland, M.Z., & Cuqlock–Knopp, V.G. (1992). Probing the mental models of system state categories with multidimensional scaling. International Journal of Man–Machine Studies, 36, pp. 673–696.
TOPIC: Mental models/multidimensional scaling
Identifying the underlying decision criteria used by people to classify system state is one of the major challenges facing designers of decision aids for complex systems. This research describes the use of multidimensional scaling (MDS) to probe the structure and composition of the mental models employed by users to identify system state and to evaluate the impact of different display formats on those models. Twenty people were trained to classify instances of system data. Pairwise similarity ratings of instances of system data were analyzed by MDS to reveal the dominant dimensions used in the task. Results showed that significant individual differences emerged and that the dimensions used by people were also a function of the type of display format.
1. Independent variables
2. Dependent variables
Somewhat useful, with the exception of some of the conclusions the authors reached regarding display designs. The methodology and system studied are too different from Task E's purpose and interest; however, some of the general conclusions they reached should possibly be considered in working on Task E.
CRITICAL FINDINGS1. Conclusions
2. Design concepts
3. General concepts
Denning, S., Hoiem, D., Simpson, M., & Sullivan, K. (1990). The value of thinking–aloud protocols in industry: A case study at Microsoft Corporation. In Proceedings of the Human Factors Society 34th Annual Meeting (pp. 1285–1289). Santa Monica, CA: Human Factors Society.
TOPIC: Verbal protocol
Thinking–aloud protocols traditionally have been used by academic researchers as a qualitative data collection method. This method is currently gaining acceptance in industry usability testing. The Usability Group at Microsoft has adopted the thinking–aloud protocol as a primary method for obtaining data from users. The authors found the method valuable, not only because it is valid for gathering qualitative data, but also because it is responsive to the constraints faced and the organizational culture in the workplace. The issue of validity has been discussed in detail by researchers, such as Deffner and Rhenius, and Ericcson and Simon. The case study further pursues the validity of thinking–aloud protocols and also discusses how this method allows the researcher to work within industry constraints and incorporate changes into the product within a small timeframe. Finally, the case study demonstrates how thinking–aloud protocols fit in well with Microsoft's corporate culture, where understandable and persuasive results are needed. This case study will have particular relevance for usability practitioners in industry.
Although this article is directed towards the usability testing of products at Microsoft, it is very useful. It describes a time–saving method that is very useful in analyzing verbal protocols. In addition, it emphasizes the value of thinking–aloud protocols when evaluating incomplete products or products at the conceptual stage.
3. Incomplete products
Thinking–aloud protocols can encourage discussion about a product even when it is in an unfinished state, especially when used in a co–discovery setting (teams of subjects read the introductory guide and worked together in a co–discovery situation to explore the system's interface and the concept introduced in the training). Microsoft had a prototype of the application that was not fully functional. Tasks were designed to allow subjects to use the pieces of the interface that were functional and to come into contact with the pieces that were still to be implemented. Subjects were instructed to verbalize all their thoughts while they used functional parts of the product and to verbalize their expectations when they tried to use something that obviously was not implemented.
Drury, C.G., Paramore, B., Van Cott, H.P., Grey, S.M., & Corlett, E.N. (1987). Task analysis. In G. Salvendy (Ed.), Handbook of Human Factors (pp. 370–401). New York: Wiley & Sons.
TOPIC: Task analysis
Task analysis is a formal methodology, derived from systems analysis, which describes and analyzes the performance demands made on the human elements of a system. By concentrating on the human element in systems analysis, it can compare these task demands with known human capabilities. The goal of task analysis is to provide the basis for integrating humans and machines into a total human–machine system. A task analysis defines the performance required of humans, just as an engineering analysis defines the performance required of hardware and a program flowchart defines the performance of software. All three are necessary. In this chapter, the origins and antecedents of task analysis are explored for the understanding they can provide of modern developments in both military and industrial systems. These modern developments are described in some detail to show that there is no single method of task analysis applicable to all jobs. Finally, an example of a large, complex system is presented in detail to illustrate both the techniques of task analysis and the methods of collecting the information required.
Useful to identify some of the numerous approaches that have been used in task analysis. Not detailed enough to follow any one specific method. Some examples could help in the understanding. Good theoretical reference material if a justification or an introductory paragraph needs to be written on the subject.
CRITICAL FINDINGS1. Human performance in technological systems
2. Nature of tasks in technological systems
Erlichman, J. (1992). A pilot study of the in–vehicle safety advisory and warning system (IVSAWS) driver–alert warning system design. In Proceedings of the Human Factors Society 36th Annual Meeting (pp. 480–484). Santa Monica, CA: Human Factors Society.
TOPIC: Warning systems
This pilot study was conducted to obtain preliminary information regarding alternative signaling presentations and symbologies for the Driver–Alert Warning System (DAWS) design within the In–Vehicle Safety Advisory and Warning System (IVSAWS) program sponsored by the Federal Highway Administration. Preliminary analysis had been conducted by both Hughes Aircraft Company and the University of Michigan Transportation Research Institute. The pilot study concentrated on the driver attributes of understanding, relative effectiveness, and signaling format. Thirteen subjects were exposed to the new pictograms prototyped on a Macintosh computer and were requested to verbalize their understanding and preferences with regard to varying signaling characteristics. These characteristics included: (a) monochrome, (b) color, (c) blink, (d) tone, (e) text message, and (f) voice message. The results indicated that as a group, the combination of color, audio tone, text, and voice message was the preferred signaling presentation. Gender differences were noted with the female subjects indicating a preference for the combination that included color and blink. All pictograms were recognizable by the subjects, and all subjects agreed that IVSAWS would be a substantial aid to the driver.
1. Independent variables
2. Dependent variables: Rank order judgments (ordinal), commentaries, and opinions (nominal).
Somewhat useful if interested in drivers' preferences for the design of DAWS. This study was a pilot study evaluating alternative signaling presentations, codes, and symbologies.
1. Subjects preferred a signaling presentation (pictogram) that added each of the following characteristics: color, audio tone, text, and visual message (with both long and short messages).
2. Females subjects (4 out of 13 subjects) preferred the color + blink option. They interpreted the blink as a more immediate danger.
3. Long message and short message text and voice options rank higher than other options. Preferred by the 16– to 30–year–old group, followed by the age 51+ group.
4. Monochrome pictograph was ranked the lowest.
5. In general, data showed a preference for associating the pictogram to a voice and a text message that provided meaningful hazard/traffic recommendations.
6. Disparity between females and males for these categories only.
7. The audio tone would be more meaningful if they represented the sounds associated with the expected emergency. In general, audio tones were associated with a need to attend to a function and, therefore, should not be eliminated.
Fath, J.L., & Bias, R.G. (1992). Taking the task out of task analysis. In Proceedings of the Human Factors Society 36th Annual Meeting (pp. 379–383). Santa Monica, CA: Human Factors Society.
TOPIC: Cognitive task analysis
Task analysis is a well–accepted component of user–centered design. It is often left out of the design process, however, due to a lack of practical methods, the difficulty in predicting the amount of resources required to perform it, and a short supply of people with the appropriate skills. A solution to these problems is a structured set of activities that make up a task analysis and relate to the overall design process.
The general framework into which these activities fit has three phases: data collection, data analysis, and design. During the data collection phase, user and task data are collected and validated. The data analysis phase requires analysis of user and task data in a way that results in suggestions for information representation, navigation, terminology, and consistency. Finally, the design phase requires translating the suggestions from the data analysis phase into a viable product.
A prototype task analysis workbook was developed to assess the feasibility of the structured approach to task analysis. The workbook includes tools for data collection, data analysis, and design, as well as instructions on how to use the tools. Over a period of 2 years, the workbook was used in five different development projects. A representative from each group was interviewed to determine how the workbook was used and which parts were most useful. Results of the interviews indicate that the workbook approach has merit.
Very useful in providing a structured approach and method to conduct a task analysis. Easy to follow and well organized. For each set of activities, the authors provide a set of tools that help perform these activities. It might be interesting to ask for a copy of their workbook (1992). Even though it is directed to the development of computers (IBM), it still might prove useful, especially for what is called "Phases 1 and 2."
1. Structured activity set for Task Analysis (TA)
2. Useful tools
3. Usefulness of workbook. Provides users with a starting point; it helps to organize task information and to identify gaps in that information, as well as to allocate design resources.
Haselkorn, M.P. (1992). Making sense of advanced traveler information systems by understanding travelers. ITE Compendium of Technical Papers, pp. 52–56.
TOPIC: ATIS – users' behavior
This paper has three parts. The first part examines the informational approach to dealing with traffic congestion, placing this approach in the context of other approaches to transportation problems. The second part looks at the complexities of ATIS design and technology. The third part looks at traveler behavior as a way to deal with these complexities.
Very useful. Describes some of the functions that ATIS should have. Describes drivers' behavior (four groups of drivers) and how they will react to ATIS based on a study done in Seattle.
1. Goals of IVHS and ATIS. Give people more choices, make those choices easier to access, and give accurate information on the consequences of those choices.
2. Control system
4. Users' behavior
King, G.F. (1986). Driver attitudes concerning aspects of highway navigation. Transportation Research Record, 1093, pp. 11–21.
TOPIC: Driver attitudes
A comprehensive questionnaire dealing with various aspects of highway navigation was developed, pretested, and administered to a demographically representative sample of the United States driving population. The sample was drawn from a group of paid subjects engaged in highway navigation experiments. The analysis of 125 completed and usable questionnaires is presented. In addition to background information on demographics and driving experience, topics addressed included route selection, behavior under directional uncertainty, distance–time–cost trade–offs, and attitudes toward proposed remedial measures. The data obtained indicate that drivers are, generally, fairly satisfied with their ability to perform route–planning or route–following tasks effectively and believe that the major constraints on their effectiveness arise from the unavailability of adequate and accurate route and traffic information. This satisfaction, however, is not supported by data on the extent of excess travel due to navigational waste. Furthermore, answers to a number of questions indicated an insufficient appreciation of the complexities of determining optimum routes and of the extent and seriousness of the problem of navigational waste.
Somewhat useful for obtaining an idea of how drivers view their own navigation and map–reading skills, what they feel are their weaknesses, as well as their willingness to have an automated system doing some of the work for them.
1. Efficiency of route selection and route following may be affected by driver age, sex, education, and driving experience. The degree of trip optimization may be affected by driver attitudes; beliefs; and behavior patterns, such as selection of route choice criteria, perceived driving costs, and distance–time trade–off patterns.
2. Perceived driving costs. Subjects' estimated costs were of the correct order; however, female estimations were higher and more variable.
3. Distance–time trade–offs. Less than one–fourth of all respondents were willing to make any trade–offs for savings of 1 min.
4. Trip planning behavior and skills. Subjects had a fairly high opinion of their route–planning and route–following skills. Male subjects were more likely to resort to maps and female subjects were more likely to ask for directions. Most subjects tried two or three alternate routes, and evaluation of four or more routes was infrequent.
5. Evaluation of candidate remedial measures. Improvements in signing, in map availability and accuracy, and in real–time traffic information were rated as being of greater importance by the subjects. Improving skills was considered less important than improving performance aids. Assistance in, or delegation of, the trip–planning and route–following tasks was ranked rather low.
6. The low rating of navigation and guidance systems might have been due to the relative unfamiliarity of the concepts involved, which would also be explained by the highest variability in the data.
7. Willingness to pay for improvements. Subjects' willingness to pay was considerably less than the anticipated probable costs for the various measures suggested.
8. These results suggest that subjects appear to have an insufficient appreciation of the complexities of determining and following optimum routes.
Labiale, G. (1989). Influence of in–car navigation map displays on drivers' performance. SAE Technical Paper Series (SAE No. 891683, pp. 11–18). Warrendale, PA: Society of Automotive Engineers.
TOPIC: Map displays
Different in–car navigation map displays have been tested with 60 drivers in real driving situations. The independent variable took into account three variables of guidance information (map alone, map associated with auditory guidance information, and map associated with written guidance information); two variables of itinerary complexity (number of turns); and two variables of information complexity (number of symbols). The dependent variables were composed of visual explorations, the memory recalling performance, the preference of map designs, the steering–wheel movements, and the speed variations of driving. The results have shown that map presentation associated with written directions resulted in a majority of the drivers being able to recall the route to follow. The complexity of map display designs had significant effects on the number and the duration of visual explorations and memorization performances. In the case of subjective preferences, most drivers preferred the simple map display design. Moreover, it was found that drivers reduced the speed of their vehicles while consulting the map displays. In conclusion, it was possible to propose some recommendations concerning the designs of navigational maps on board vehicles.
1. Independent variables
2. Dependent variables. Time spent looking at display, memory recall of route, preference of map display, steering–wheel movements, and speed variation of driving.
3. Data analysis techniques. ANOVA, X2.
Useful only if we are interested in driver's preference and performance using various map displays. No task analysis or task descriptions.
1. Less time is spent glancing at a visual display when it is combined with auditory information than compared to a map alone or a map combined with written information.
2. Complexity of the routes has a negative influence on drivers' ability to recall an itinerary, especially when driving.
3. Average glances at the display are 1.28 s; 92.3 percent of all glances were 2 s or less (some could be as long as 4.8 s).
4. This effect was independent of the type of maps. Many more errors and omissions were noted for road names than for the drivers' ability to find their way.
5. Drivers preferred maps with auditory information (48 percent) over maps alone (34 percent) and maps with written information (17 percent), even though maps with written information led to the best recall (69 percent).
6. Author recommended:
Labiale, G. (1990). In–car road information: Comparisons of auditory and visual presentations. In Proceedings of the Human Factors Society 34th Annual Meeting (pp. 623–627). Santa Monica, CA: Human Factors Society.
TOPIC: Map displays
Two studies investigate the effects of presentation modalities (visual/auditory/repeated auditory) and complexity levels of different in–car road information on subjective preferences and on perceptual and cognitive performances of drivers. In real driving situations, each driver was alerted by a ringing signal prior to the presentation of a road information message or a map display associated with a road guidance message; the experimenter asked each driver 30 s later to recall the message or the itinerary. Results suggest that in real driving situations, short auditory road information messages or those associated with map displays optimize perceptual and cognitive performances and driving safety; written messages are of greater interest if screened when the vehicle is at rest.
1. Independent variables
2. Dependent variables. Recall performance, subjective preferences of modalities, visual exploration, vehicle course, and speed control.
3. Data analysis techniques. ANOVA, X2.
Somewhat useful. The findings are similar to the ones found in another study by Labiale. It is useful to identify the amount of information that a driver can handle, both visual and auditory.
1. Drivers feel that auditory information is safer than visual information and it is preferred for messages of Levels 3 and 4. Drivers prefer maps associated with auditory guidance (71.8 percent) to the ones with visual guidance (28.1 percent).
2. Visual stimulus disturbed the driving task at higher levels of display complexity, both in course deviation and slowing of speed.
3. The optimal perceptual and cognitive solution seems to be an auditory message using a maximum of 7 to 9 informational units for road information, or if used visually, as a prompt to a very simple visual map or guidance presentation.
4. Recall at Level 1 is 100 percent and 48.4 percent at Level 4.
5. Increasing the message length increases the number of visual fixations and the overall duration of visual explorations, but not necessarily the average duration of each visual fixation.
Lunenfeld, H. (1990). Human factor considerations of motorist navigation and information systems. In Proceedings of First Annual Vehicle Navigation and Information Systems Conference (pp. 35–42). Warrendale, PA: Society of Automotive Engineers.
TOPIC: Human factors – IVNS
In–Vehicle systems have the potential for ameliorating problems associated with navigation and operations, including delay, excess fuel consumption, congestion, and increased safety risk. A proliferation of vehicle–based systems, however, has resulted in a lack of standardization and a diversity of functions. User interfaces are crucial to system effectiveness. Therefore, while display and control configurations will ultimately be determined by the marketplace, it is important that human factors be addressed and guidelines be developed. This will ensure standardization and display and control optimization. Human factors have been considered in terms of seven questions: Why? What? When? Where? How? Who? and Can?
Very useful with respect to describing the individual task of driving, as well as in terms of the nature of the information required, display characteristics, users' limitations, and characteristics to enhance the efficiency of these systems.
1. Driving task
2. Navigational information
3. Navigational error
5. Display considerations
6. User characteristics. Anthropometrics, vision, hearing, time and task sharing, and memory.7. Decrements
Noy, Y.I. (1989). Intelligent route guidance: Will the new horse be as good as the old? In Vehicle Navigation and Information Systems Conference Proceedings (pp. 49–55). Toronto, Ontario, Canada: International Ergonomics Association.
TOPIC: Intelligent route guidance systems
Automobile navigation systems are undergoing rapid technological evolution following advances in microprocessors and artificial intelligence. The present study was initiated to investigate the human factors of intelligent automobile displays with a view towards determining the need for design guidelines. The experiment was designed to examine the relationship between drivers' visual attention and performance under concurrent multi–task conditions. Twenty young male and female students with normal vision and a minimum of 3 years of driving experience were randomly assigned to two groups in a mixed, three–factor experiment. Subjects drove in a moving–base simulator and performed cognitive tasks on a CRT display that was located on the instrument panel to the right of the driver. The two display tasksðCa spatial perception task and a verbal memory taskðCwere designed to place differential demands on cognitive resources. Subjects were instructed to perform their best on the display and driving tasks, giving priority to the driving. Display task difficulty and driving difficulty were manipulated within subjects. Task type (memory and perception) was the between–groups factor. Eleven dependent variables provided measures of driving performance, attentional behavior, display task performance, and workload. In addition, on–line eye movement sampling indicated whether the subject looked at the roadway or at the computer display. Results are discussed in relation to the need for ergonomics guidelines for the design of navigation displays.
1. Independent variables. Simulated driving task.
2. Dependent variables
3. Controls. Measures were taken for driving alone, auxiliary task alone, and auxiliary tasks with simulated movement to reduce confounds.
4. Purpose of research
Very useful. Provides interesting findings regarding driver behavior when working on an auxiliary task, which could be compared to using an intelligent route guidance system.
1. Effects of auxiliary task load on driving
2. Effects of driving load on driving performance
3. Effects of task load on attention
4. Effects of driving load on attention
5. Effects of gaze direction on driving
Nystuen, J.D. (1990). A framework for assessing travel behavior response to Intelligent Vehicle–Highway Systems. SAE Technical Paper Series (SAE No. 901509, pp. 103–111). Warrendale, PA: Society of Automotive Engineers.
TOPIC: IVHS – Transportation System Model
Identification of a framework for assessing the consequences of adopting IVHS applications is presented. IVHS applications modify vehicle–highway capacities by enhanced information processing. Mobility opportunities change and, if acted upon, change individual travel behavior. Changes in individual travel behavior affect aggregate travel behavior and transportation network loadings. Decisions to change the transportation system cycle through a three–step social action process involving goals and aspirations, knowledge and technology, and financial and legal capacity to act. Action is then constrained by opportunities available in the environment. The transportation system model presents a framework for designing research to estimate the requirements and consequences of adopting the new technology.
Limited use except maybe for the Transportation System Model. The model possibly could be used to identify the chain of consequences that flow from adoption of physical devices or systems to travel behavior responses to secondary responses, and to the distribution of benefits between users and non–users.
1. The Transportation System Model shows the relationship between evaluation of mobility opportunities, individual and aggregate travel behavior, and spacial choice over a range of time frames. In summary, the models seems to indicate:
2. There is an implicit assumption that the IVHS research and development community holds, that as a society, we want to keep out individual, high–speed mobility.
3. The main thrust for policy planning is that IVHS is evolving in a distributed system where no one is in charge (may have been true in 1990; is it nowadays?).
4. New travel behavior may call for new rules for governing transport as risk and responsibility shift.
Petchenik, B.B. (1989). The nature of navigation: Some difficult cognitive issues in automatic vehicle navigation. In Vehicle Navigation and Information Systems Conference Proceedings (No. CH2789–6/89/0000–0043). Toronto, Ontario, Canada.
TOPIC: Automatic vehicle navigation system
If one believes everything one reads in the newspapers, a technology for providing automatic car navigation is virtually in place. But, in fact, this is far from true. It is the purpose of this paper to demonstrate that finding one's way from place to place while driving a car is a complex cognitive task, and that if there is to be authentic computer–based assistance to drivers, it must come from devices and systems significantly different from the digital dashboard maps that have been offered to date.
Not very useful. Very general and broad approach. Does not add much to what we already know. Actually, in some cases, the article makes wrong assumptions.
1. Navigation environment falls into four categories:
2. In addition to these visible environments, the driver must be aware of and integrate information from at least five additional domains:
Redding, R.E. (1990). Taking cognitive analysis into the field: Bridging the gap from research to application. In Proceedings of the Human Factors Society 34th Annual Meeting (pp. 1304–1308). Santa Monica, CA: Human Factors Society.
TOPIC: Cognitive Task Analysis (CTA)
Cognitive methods of task analysis have been used for training development. Although quite promising, these methods are generally time consuming, labor intensive, and require considerable expertise. This has precluded their full use in field training situations. Economical, practical, and user–friendly methods are needed that can be integrated easily with current approaches. This symposium paper discusses the potential of cognitive task analysis as well as the practicality problem. Of particular concern is how cognitive methods can receive widespread application among training practitionersðChow to transition theory and research in cognitive task analysis into mainstream training development programs.
Somewhat useful in terms of the elements to be considered when performing a cognitive task analysis. Aside from these points, the article is quite basic and general in its content.
1. Goals of CTA
2. Difference between traditional and cognitive task analysis
4. Tasks that should be analyzed. Tasks that require a high degree of problem solving and decision making place high workload requirements on the individual, require a well–developed conceptual knowledge base, and represent bottlenecks or problems in job performance or in which there are frequent errors.
Roth, E., Bennett, K., & Woods, D.D. (1988). Human interaction with an "intelligent" machine. In E. Hollnagel, G. Mancini, & D.D. Woods (Eds.), Cognitive Engineering in Complex Dynamic Worlds. New York: Academic Press.
TOPIC: Problem solving/expert systems
This paper reports the results of a study of technicians diagnosing faults in electro–mechanical equipment with the aid of an expert system. Technicians varying in level of experience and interactive style (active or passive) diagnosed faults varying in level of difficulty. The results indicate that the standard approach to expert system design, in which the user is assigned the role of data gatherer for the machine, is inadequate. Problem solving was marked by novel situations outside the machine's competence, special conditions, underspecified instructions, and error recovery, all of which required substantial knowledge and active participation on the part of technicians. It is argued that the design of intelligent systems should be based on the notion of a joint cognitive system architecture: computational technology should be used to aid the user in the process of solving his or her problem. The human's role is to achieve total system performance as a manager of knowledge resources that can vary in kind and amount of intelligence or power.
Useful for its innovative approach on how support systems should be designed. The authors divert from the traditional approach to design support systems as prostheses (replacement or remedies for deficiencies) to a more innovative approach that considers support systems as a cognitive instrument (deploy machine power to assist human performance).
1. Two fundamental approaches to system design
2. Analysis of protocols. Problem–solving episodes were analyzed by charting the flow of judgments and actions that were made either by the machine or by the operator, and comparing the actual path of each episode to the canonical path.
3. Performance analysis
4. Reasons for deviations from the canonical path
Senders, J.W., Kristofferson, A.B., Levison, W.H., Dietrich, C.W., & Ward, J.L. (1967). The attentional demand of automobile driving. Highway Research Record, 195, pp. 15–33.
TOPIC: Attentional demands
A theoretical analysis and an experimental investigation of certain aspects of automobile driver information processing were undertaken. The theoretical analysis was the result of an effort to avoid difficulties associated with a servomechanistic approach to the automobile driving problem. The analysis is predicated on the assumption that a driver's attention is, in general, not continuously, but only intermittently, directed to the road. Between observations, uncertainty about both the position of his own vehicle on the road and the possible presence of other vehicles or obstacles increases until it exceeds a threshold. At that moment in time, the driver looks again at the road. This simple model appears to be a useful analog of the driving process. The analysis makes specific predictions about the form of the functional relationship between intervals and between observations and vehicle speed. The experimental program had two goals. One was the empirical investigation of the relation between amount of interruption of vision and driving speed. The other was the determination for various drivers and various roads of the values of some of the parameters in the mathematical model. This report presents the results of the theoretical and experimental investigation. In general, the model is a fair approximation of actual behavior and it remains for future work to determine whether this approximation is good enough to be useful for the specification of vehicle, highway, and user characteristics.
METHODOLOGY1. Independent variables. Four experiments using two kinds of roads (easy and difficult) and two procedures (fixed occlusion and viewing time, fixed velocity and viewing time).
2. Dependent variables. Speed (mi/h), viewing time (s), and occlusion time (s).
3. Control conditions. Not applicable.
4. Data analysis techniques. Not applicable.
5. Methodology. Test track road.
Not useful for this task. It is useful in determining how much attention may be demanded of a driver for varying road types and speeds and to compare these results using a mathematical approach.
1. The higher the speed, the shorter the interval needed between observations.
2. The less frequent the observations or the shorter the period of observations, the slower the speed the driver can maintain.
3. Authors suggest that drivers tend to drive to a limit and that limit is determined by the point when the driver's information–processing capacity, either real or imagined, is matched by the information generation rate of the road, either real or estimated.
Smiley, A. (1989). Mental workload and information management. In Vehicle, Navigation, and Information Systems Conference Proceedings (pp. 435–438). Toronto, Ontario, Canada.
TOPIC: Subjective workload
The use of high technology in vehicles has the potential of greatly increasing the amount of information presented to a driver. The need for the new support systems to be sensitive to the mental workload experienced by the driver is discussed. Primary task, secondary task, and physiological and subjective measures of mental workload are described. The contribution of task difficulty, effort, and arousal to the driver's subjective mental workload is discussed. The manner in which each of these factors might be measured on–line is described. Finally, system adaptations that might be made at high levels of mental workload are suggested.
REVIEW OF ARTICLE
Somewhat useful for its theoretical approaches to workload measures and their usefulness in in–vehicle support systems. Does not add much that is not already known.
1. Important not to overload drivers at critical times during the driving task (e.g., intersections, curves, and heavy traffic). Have to consider more than just task difficulty because the same task can be perceived differently by different drivers.
2. The high technology support systems will have to be:
3. Two major uses of the four mental workload measures are:
4. Visual capacity: a driver of a 1.8–m car traveling in a lane 3.7 m wide, at 50 km/h, and reading text in a vehicle for 2, 4, and 6 s would have probabilities of laterally deviating out of the lane of 0.05 percent, 1.1 percent, and 8.7 percent. Reducing the lane width increases these probabilities. Mental workload can be reduced if visual material is presented in small chunks and at a slow rate.
5. Contributing factor to subjective mental workload: task difficulty, driver effort, and driver arousal.
Thordsen, M.L. (1991). A comparison of two tools for cognitive task analysis: Concept mapping and the critical decision method. In Proceedings of the Human Factors Society 35th Annual Meeting (pp. 283–285). Santa Monica, CA: Human Factors Society.
TOPIC: Cognitive task analysis
Two knowledge elicitation tools for cognitive task analysis are described and compared: Concept Mapping (CM) and the Critical Decision Method (CDM). CM is a procedure that can be used to represent the interviewee's conception of a task by developing a graphical schematic of the perceptions of the task's components. It is appropriate when one needs to capture the interviewee's cognitive organization of the task's routine elements and how these elements fit together. CDM is highly effective at eliciting tacit knowledge about perceptions, expertise, and aspects of a domain that are often difficult for experts to articulate. It has proven to be an effective tool for capturing the deeper, difficult–to–articulate knowledge that separates experts from novices. Used together, these techniques can be very complementary and effective. CM provides an overview of the user's image of the task, including information about the clustering of and flow between concepts. CDM is an effective tool for identifying decision strategies, critical cues, situation assessment, goals and intent, expectancies, mental simulation strategies, and improvisation. Used in combination, the techniques can effectively generate recommendations for training and display design.
Useful. Some aspects of these two task analyses could be useful to Task E. The Critical Decision Method is an interview process that has been developed for the analysis of critical incidents. As a consequence, it might be difficult to transfer to the type of usage required for Task E, but it is recommended as a method for providing display design recommendations. Concept Mapping is also an interview process that produces a schematic representation of the relationships among a task's components. It might be applicable to this project.
1. Concept Mapping (CM)
2. Critical Decision Method (CDM)
Wierwille, W., Hulse, M., Fisher, T., & Dingus, T. (1988). Effects of variations in driving task attentional demand on in–car navigation system usage. General Motors Research Laboratories Contract Report No. CR–88/02/05. Warren, MI.
TOPIC: Attentional demands
Earlier studies have shown that drivers' visual scan patterns and dwell times are changed when using an in–car navigation display system. The fact that these changes occur raises questions about a driver's ability to adapt appropriately to high–demand driving situations. Thus, additional experiments were conducted to determine whether or not drivers adapt appropriately to high driving task demands while simultaneously navigating. One experiment was designed to investigate adaptation to high anticipated driving task demands, and a second was designed to investigate adaptation to high unanticipated driving task demands. The results of the two experiments demonstrate clearly that as driving task demands increase, drivers do indeed shift their visual sampling strategy appropriately. However, variability in the data suggests that good human factors design and appropriate placement of the display remain important issues.
1. Independent variables. Two experiments:
3. Data analysis. ANOVA, MANOVA.
4. Controls. Subjects were trained. They drove to unknown destinations all the time. They were used for both experiments (two runs in the first, three in the second).
Somewhat useful if the reader's interest is in finding out how a navigation system affects drivers' attention, as measured by eye movements. The article has implications for the positioning of these instrumentations and their impact on the driving task.
1. For increases in both anticipated and unanticipated driving demands, drivers increased the proportion of time spent on the forward central view and decreased the proportion of time spent observing the navigator.
2. Increased anticipated demands resulted in an increased visual sampling rate by the drivers. The length of the sampling rate was shorter for anticipated driving demands and longer for unanticipated driving demands.
3. For increased unanticipated demands, the visual sampling rate decreased and drivers concentrated on the forward view with longer glances.
ADDITIONAL RELEVANT LITERATURE
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Keywords: Advanced Traveler Information System (ATIS); Commercial Vehicle Operations (CVO); Intelligent Vehicle-Highway Systems (IVHS)
TRT Terms: Highway communications, Trucking--Technological innovations, Trucks--Communications systems, Advanced traveler information systems, Commercial vehicle operations, Human factors