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Publication Number: FHWA-RD-98-057

Human Factors Design Guidelines for Advanced Traveler Information Systems (ATIS)and Commercial Vehicle Operations (CVO)

 

CHAPTER 6: MOTORIST SERVICES GUIDELINES

 

This chapter provides human factors design guidelines relevant to Motorist Services Functions of ATIS devices. Motorist Services Functions provide motorists with commercial logos and signing for motels, eating facilities, service stations, and other signing displayed inside the vehicle to direct motorists to recreational areas, historical sites, etc. Motorist Services Functions provide routing information for local destinations.

The following design topics are included in this chapter:

DRIVER CONVENIENCE

COMMUNICATIONS

 

PRESENTATION OF SERVICES/ATTRACTION INFORMATION

Introduction: Services/attraction information refers to information provided to travelers which is normally found on commercial road signs or in the yellow pages of a phone book. This information should not be provided unless specifically requested from the driver. However, the information presented can be filtered to present only those services/attractions which meet a certain profile of the driver's interests.

Design Guidelines**

Information Element

Display Type

Trip Status

Display Format

Description and costs of services/attraction

Visual

Vehicle at
a Stop

Iconic or graphic representation with text

Location of services/attraction

Auditory and Visual or Visual

Vehicle
in Motion

Tone to indicate arrival, partial route map with text or icons, or sortable text list

Availability of services/attraction

Auditory and Visual
or Auditory

Vehicle
in Motion

Iconic or graphic representation with tones

Distance from present location to services/attraction

Auditory and Visual or Auditory

Vehicle
in Motion

Iconic or graphic representation with tones or partial route map with voice

 

Schematic Example of Presenting Services/Attraction Information

Schematic Example of Presenting Services/Attraction Information

Important Note: The map display depicted above is provided solely to augment this Design Guideline by illustrating general design principles. It may not be suitable for your immediate application without modification.

Supporting Rationale: In Reference 1, a literature review, an analysis, and the results of applying a research–based design tool were used to identify the most appropriate display type, trip status, and display format to use when displaying services/attraction information. It was determined that complex information would be displayed more effectively through the visual channel than through the auditory channel (Reference 2). However, because this information might be presented while the driver is engaged in the driving task, it might be necessary to simplify the messages into smaller units and display them through the auditory channel as well. This would prevent the messages from detracting attention from the driving task or from significantly increasing the driver's workload. It was also determined that this type of information would be more valuable to the driver if given in transit; the benefit of having this type of information would outweigh the costs, in terms of information processing and control requirements.

Special Design Considerations: Using current technology, the driver would need to consult the yellow pages of a phone book, see information on a road sign, or use a telephone to get information about hotels, attractions, restaurants, and available services. The purpose of this function is to consolidate all of these sources into one information system. While this information is useful to the driver, it is neither as urgent nor as important as safety information from other ATIS subsystems. Given this, the displays for this function will need to be designed so that they are less intrusive and can display information efficiently to ensure the ability to display safety information.

Additional research for this function is needed to define the amount of information that drivers would prefer to have displayed to them at any given time. If the capability to advertise services and attractions through this system is fully developed, a method of filtering or limiting the amount of information being displayed will be necessary to avoid overloading drivers with in–vehicle commercial information. Efficient display of motorist service information might include the use of integrated or grouped information elements. For example, information such as the description, location, and distance of travel for motorist services might be grouped and accessible to the driver by a single information request.

Guidelines for services/attraction information for ATIS reflect certain assumptions regarding the priority, length, and complexity of messages. These assumptions may not apply to all design situations.

Cross References:

Presentation of Preference and Directory Information

Presentation of Destination Coordination Information

The Message Transfer Function

Trip Status Allocation Design Tool

Key References:

    1. Hulse, M. C., Dingus, T. A., Mollenhauer, M. A., Liu, Y., Jahns, S. K., Brown, T., & McKinney, B. (1997). Development of human factors guidelines for Advanced Traveler Information Systems (ATIS) and Commercial Vehicle Operations (CVO): Identify strengths and weaknesses of alternative information display formats. Washington, DC: Federal Highway Administration (FHWA–RD–96–142).

    2. Deatherage, B. H. (1972). Auditory and other sensory forms of information presentation. In H. Van Cott & R. Kinkade (Eds.), Human engineering guide to equipment design, (rev. ed.) (pp. 123–160). Washington, DC: U.S. Government Printing Office.

*Primarily expert judgement
**Expert judgement with supporting empirical data
***Empirical data with supporting expert judgement
****Primarily empirical data

 

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PRESENTATION OF PREFERENCE AND DIRECTORY INFORMATION

Introduction: Preference and directory information refers to information similar to that found in the yellow pages. However, unlike a yellow pages directory, the services/attractions directory has the flexibility of a computer database and would facilitate a wide variety of search methods. For instance, in searching for a shopping center, one parameter might be its physical location, which might be specified using an electronic map and touch screen. Providing the system with preference information allows it to assess information concerning businesses or attractions that satisfy the driver's current need.

Design Guidelines**

Information Element

Display Type

Trip Status

Display Format

Directory (index of yellow pages)

Visual

Vehicle at a Stop

Iconic or graphic representation with text or text description

View currently selected preferences

Visual

Vehicle at a Stop

Iconic or graphic representation with text or text description

 

Schematic Example of Presenting Preference and Directory Information

Schematic Example of Presenting Preference and Directory Information

Important Note: The graphic depicted above is provided solely to augment this Design Guideline by illustrating general design principles. It may not be suitable for your immediate application without modification.

Supporting Rationale: In Reference 1, a literature review, an analysis, and the results of applying a research–based design tool were used to identify the most appropriate display type, trip status, and display format to use when displaying preferences and directory information. It was determined that this information would be best presented while the vehicle was stopped briefly during the normal drive (zero speed). In this situation, drivers are able to devote nearly full attention to the system, but the time available for work with the system is limited by the duration of the traffic control device or any other cause of the zero–speed condition. Therefore, operations during a zero–speed situation must typically take less time than those available during a predrive situation. An estimate of the average stop duration at a red light is about 10 seconds. Therefore, this number is used as a criterion for allocating information to the zero–speed category.

It was also determined that the information should be presented visually due to the amount of information being displayed on the screen and the number of display interactions necessary for selecting preferences. Any time there are more than 7 to 9 units of related pieces of information, the information is considered to be complex (Reference 2 and 3). Complex information is displayed more effectively through the visual channel.

Special Design Considerations: A primary factor limiting a traveler's use of the system would be the driver's attitudes and knowledge regarding the system. The driver must know how to use the system (although it should be designed to be self–explanatory), and the traveler must have confidence that the system can deliver valuable information. Therefore, designers should concentrate more on HCI issues such as how the driver will input their preferences and how that information will be displayed.

Since drivers must specify complicated information concerning their needs, the system may include a touch screen menu system or a remote keypad. Reference 4 examined the visual, safety and performance aspects of operating a simulated CRT touch panel display while driving at a constant speed along a straight path, with respect to lateral lane position maintenance. Looking at and/or operating a CRT touch panel while driving a vehicle along a straight path appears to be a visually demanding, if not dangerous task, as demonstrated by the relatively high probabilities of lane deviations. Therefore, presenting this information during zero speed, as suggested in the above guideline, appears to be the best option.

Guidelines for preference and directory information for ATIS reflect certain assumptions regarding the priority, length, and complexity of messages. These assumptions may not apply to all design situations.

Cross References:

Presentation of Services/Attractions Information

Presentation of Destination Coordination Information

The Message Transfer Function

Trip Status Allocation Design Tool

Key References:

    1. Hulse, M. C., Dingus, T. A., Mollenhauer, M. A., Liu, Y., Jahns, S. K., Brown, T., & McKinney, B. (1997). Development of human factors guidelines for Advanced Traveler Information Systems (ATIS) and Commercial Vehicle Operations (CVO): Identify strengths and weaknesses of alternative information display formats. Washington, DC: Federal Highway Administration (FHWA–RD–96–142).

    2. Labiale G. (1990). In–car road information: Comparisons of auditory and visual presentation. Proceedings of the Human Factors Society 34th Annual Meeting, (pp. 623–627). Santa Monica, CA: Human Factors and Ergonomics Society.

    3. Miller, G. A. (1956). The magical number seven plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63,pp. 81–97.

    4. Zwahlen, H. T., Adams, C. C., & DeBald, D. P. (1987). Safety aspects of CRT touch panel controls in automobiles. Proceedings of the Second International Conference on Vision in Vehicles (pp. 1–10). England: University of Nottingham.

*Primarily expert judgement
**Expert judgement with supporting empirical data
***Empirical data with supporting expert judgement
****Primarily empirical data

 

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PRESENTATION OF DESTINATION COORDINATION INFORMATION

Introduction: Destination coordination information refers to information which enables the driver to communicate and make arrangements with the final destination. This function may include making restaurant and hotel reservations. In addition, it may include ascertaining information about parking availability and location.

Design Guidelines**

Information Element

Display Type

Trip Status

Display Format

Confirmation of reservation

Auditory and Visual

Vehicle in Motion

Text description with voice
or speech with or without icons

Locate nearest parking

Auditory and Visual

Vehicle in Motion

Full or partial route map with voice

Type of parking facility

Auditory and Visual

Vehicle in Motion

Text description with voice
or speech with or without icons

Reservation details

Auditory and Visual

Vehicle at a Stop

Text description with voice
or speech with or without icons

Diagram of parking facilities

Visual

Vehicle in PARK

Full or partial route map with voice

 

Schematic Example of Presenting Destination Coordination Information

Schematic Example of Presenting Destination Coordination Information

Important Note: The map display depicted above is provided solely to augment this Design Guideline by illustrating general design principles. It may not be suitable for your immediate application without modification.

Supporting Rationale: In Reference 1, a literature review, an analysis, and the results of applying a research–based design tool were used to identify the most appropriate display type, trip status, and display format to use when displaying destination coordination information. It was determined that operator performance could be improved by incorporating some combination of auditory and visual stimuli. Reference 2 recommends that: (1) the auditory modality be utilized to provide an auditory prompt to look at a visual display for changing or upcoming information (thus lessening the need for the driver to constantly scan the visual display in preparation for an upcoming event), or (2) simple visual information should supplement the auditory message (so that a message that is not fully understood or remembered can be checked, or later referred to, via the visual display).

As the amount of effort required to retrieve information from a display increases due to greater levels of complexity, the trip status selected will change from presenting it while the vehicle is in motion, while it is stopped, and finally, to while it is parked. Any display that requires more than four glances (Reference 3) or requires glances longer than two seconds (Reference 4 would require significantly more visual attention than should be given while in transit and therefore should be allocated to one of the other trip statuses. In order to be completely presented during zero speed (while the vehicle is stopped during the normal drive) the information cannot take longer than the zero–speed event itself, which is a stop light in most cases. The average stop duration at a red light is about ten seconds. Information given to the driver during predrive can be complex and attention demanding, as there are no safety issues associated with overloading the driver at this point.

Special Design Considerations: Some people may prefer direct communication with the destination, and the transitory nature of parking availability may limit the predictive accuracy of the system. Therefore, usability and acceptance issues will be among the most important for designers of this subsystem. It will be very important to consider the human–computer interface issues which will make this a more effective system.

Guidelines for destination and coordination information for ATIS reflect certain assumptions regarding the priority, length, and complexity of messages. These assumptions may not apply to all design situations.

Cross References:

Presentation of Services/Attractions Information

Presentation of Destination Coordination Information

The Message Transfer Function

Trip Status Allocation Design Tool

Key References:

    1. Hulse, M. C., Dingus, T. A., Mollenhauer, M. A., Liu, Y., Jahns, S. K., Brown, T., & McKinney, B. (1997). Development of human factors guidelines for Advanced Traveler Information Systems (ATIS) and Commercial Vehicle Operations (CVO): Identify strengths and weaknesses of alternative information display formats. Washington, DC: Federal Highway Administration (FHWA–RD–96–142).

    2. Dingus, T. A., & Hulse, M. C. (1993). Some human factors design issues and recommendations for automobile navigation information systems. Transportation Research, 1C(2), pp. 119–131.

    3. Zwahlen, H. T., Adams, C. C., & DeBald, D. P. (1987). Safety aspects of CRT touch panel controls in automobiles. Proceedings of the Second International Conference on Vision in Vehicles (pp. 1–10). England: University of Nottingham.

    4. French, R. L. (1990). In–vehicle navigation–status and safety impacts. Technical Papers from ITE's 1990, 1989, and 1988 Conferences (pp. 226–235). Washington, DC: Institute of Transportation Engineers.

*Primarily expert judgement
**Expert judgement with supporting empirical data
***Empirical data with supporting expert judgement
****Primarily empirical data

 

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THE MESSAGE TRANSFER FUNCTION

Introduction: The message transfer function refers to the capability for drivers to communicate with others. Currently this function is accommodated with cellular phones and Citizen's Band (CB) radios; however, future ATIS systems may improve upon this technology. This function might include text and voice messages; however, it does not include the transmission of mayday calls. Likewise, this function is separate from the computer–aided dispatch function, but may be used with it.

Design Guidelines**

Information Element

Display Type

Trip Status

Display Format

Alert driver of message received

Auditory

Vehicle in Motion

Speech with alerting tone

Review received message

Visual or Auditory

Vehicle at a Stop, or
in Motion if speech is used

Iconic or graphic representation
with or without text or speech

Reply to a message

Auditory

Vehicle in Motion

Speech

Alert driver message was sent

Auditory

Vehicle in Motion

Speech with alerting tone

Alert driver message was
not sent and why not

Auditory

Vehicle in Motion

Speech with alerting tone

Delete message

Visual

Vehicle at a Stop

Iconic or graphic representation with or without text

Save message

Visual

Vehicle at a Stop

Iconic or graphic representation with or without text

 

Schematic Example of Presenting Message Transfer Information

Schematic Example of Presenting Message Transfer Information

Important Note: The graphic depicted above is provided solely to augment this Design Guideline by illustrating general design principles. It may not be suitable for your immediate application without modification.

Supporting Rationale: In Reference 1, a literature review, an analysis, and the results of applying a research–based design tool were used to identify the most appropriate display type, trip status, and display format to use when displaying message transfer information. It was determined that visual presentation of detailed information does have some advantages in comprehension and flexibility. Visual displays allow the driver to refer to information at a later time, and such displays are able to present a larger quantity of data in a shorter period of time. However, because of the level of visual attention that is required by the driving task, any message that must be displayed to a driver immediately, such as a critical priority message, should be presented in a manner that would not add to the visual attention load. Currently, the best way to present detailed information without compromising visual attention is by using an auditory speech display (Reference 2). An argument might be made for minimizing visual attention requirements all of the time by displaying all messages through a speech display, but research on user acceptance of speech displays indicates that they should be used sparingly. Like the visual channel, the auditory channel can quickly become cluttered or overloaded with stimuli (References 2, 3, and 4).

Special Design Considerations: The most relevant human constraint that influences how well drivers could use this function involves the driver's understanding of the ATIS menu structure and the capabilities of the system. Specifically, identifying the message recipient in a database containing several access numbers might be a difficult task for some people. Therefore, designers should concentrate their efforts in the area of human–computer interaction to ensure an easy and effective system design. Driver attitude is another factor that may play an important role in whether or not people will use this function. For instance, entering a message and specifying its destination may be cumbersome to some drivers who might prefer to convey the information directly over the phone or in person. Similarly, some users may not trust the computer's ability to deliver the message in an accurate and timely fashion.

Messages that are noncritical should incorporate a display that can signal the driver of a message event but does not need to convey a sense of urgency or importance. Noncritical messages are more routine or general and the driver is not endangered or penalized by waiting until a later time to review the message. If a sender indicates that a message is critical, the associated message event notification should be able to get the driver's attention, whether or not the display is actively being searched for information (Reference 5). Critical messages should be presented to the driver as soon as the vehicle is at a stop.

Guidelines for message transfer information for ATIS reflect certain assumptions regarding the priority, length, and complexity of messages. These assumptions may not apply to all design situations.

Cross References:

Auditory Message Length

Presentation of Services/Attractions Information

Presentation of Destination Coordination Information

Trip Status Allocation Design Tool

Key References:

    1. Hulse, M. C., Dingus, T. A., Mollenhauer, M. A., Liu, Y., Jahns, S. K., Brown, T., & McKinney, B. (1997). Development of human factors guidelines for Advanced Traveler Information Systems (ATIS) and Commercial Vehicle Operations (CVO): Identify strengths and weaknesses of alternative information display formats. Washington, DC: Federal Highway Administration (FHWA–RD–96–142).

    2. Wickens, C. D. (1992). Engineering psychology and human performance. New York: Harper–Collins.

    3. Stokes, A., Wickens, C., & Kite, K. (1990). Display technology: Human factors concepts. Warrendale, PA: Society of Automotive Engineers.

    4. Wierwille, W. W. (1993). Visual and manual demands of in–car controls and displays. In B. Peacock & W. Karwowski (Eds.), Automotive ergonomics (pp. 229–320). London: Taylor & Francis.

    5. Huiberts, S. J. C. (1989). How important is mobile communication for a truck company? IEEE, CH2789–6/89/0000–0361 (pp. 361 –364). Piscataway, NJ: IEEE.

*Primarily expert judgement
**Expert judgement with supporting empirical data
***Empirical data with supporting expert judgement
****Primarily empirical data

 

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FHWA-RD-98-057

 

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