In-Vehicle Display Icons and

Other Information Elements

Volume II: Final Report

PUBLICATION NO. FHWA-RD-03-063 SEPTEMBER 2004

Research, Development, and Technology

Turner-Fairbank Highway Research Center

6300 Georgetown Pike

McLean, VA 22101-2296
FOREWORD 

This is one of a series of reports produced as part of a contract to develop precise and detailed 

human factors design guidelines for in-vehicle display icons and other information elements. 

The contractual effort consists of three phases: analytical, empirical, and integrative. 

This report is a summary of the analytical, empirical, and integrative phases of the In-Vehicle 

Display Icons and Other Information Elements project. It is an overview of the process used to 

meet the primary goal of the project: to provide designers of in-vehicle technologies with a set of 

design guidelines for in-vehicle display icons and other information elements. 

Copies of this report may be obtained through the Research and Technology Report Center, 9701 

Philadelphia Court, Unit Q, Lanham, MD 20706; telephone: 301–577–0818; fax: 301–577–1421; 

or the National Technical Information Service (NTIS), 5285 Port Royal Road, Springfield, VA 

22161; telephone: 703–487–4650; fax: 703–321–8547. 

Michael Trentecoste 

Director 

Office of Safety Research and Development 

Federal Highway Administration 

NOTICE

This document is disseminated under the sponsorship of the U.S. Department of Transportation 

in the interest of information exchange. The U.S. Government assumes no liability for its 

content or the use thereof. This report does not constitute a standard, specification, or regulation. 

The U.S. Government does not endorse products or manufacturers. Trade and manufacturers’ 

names appear in this report only because they are considered essential to the objective of the 

document. 

QUALITY ASSURANCE STATEMENT 

The Federal Highway Administration (FHWA) provides high-quality information to serve 

Government, industry, and the public in a manner that promotes public understanding. Standards 

and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its 

information. FHWA periodically reviews quality issues and adjusts its programs and process to 

ensure continuous quality improvement. 
Technical Report Documentation Page

1. Report No. 

FHWA-RD-03-063 

2. Government Accession No. 3. Recipient's Catalog No. 

5. Report Date 

 September 2004 

4. Title and Subtitle 

In-Vehicle Display Icons and Other Information Elements: 

Volume II: Final Report 6. Performing Organization Code 

7. Author(s) 

Campbell, J. L. 

8. Performing Organization Report No. 

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 

Battelle Human Factors Transportation Center 

4500 Sand Point Way NE 

Seattle, WA 98105 

11. Contract or Grant No. 

13. Type of Report and Period Covered 

Technical 

10/1997–6/2002 

12. Sponsoring Agency Name and Address 

Office of Safety and Traffic Operations Research and 

Development 

Federal Highway Administration 

6300 Georgetown Pike 

McLean, VA 22101-2296 

14. Sponsoring Agency Code 

15. Supplementary Notes 

Contracting Officer’s Technical Representative (COTR): Thomas M. Granda. 

16. Abstract: 

Because of the speed with which IVIS devices are entering the automotive marketplace, many research issues associated 

with the design of in-vehicle visual symbols and other information elements have not been adequately addressed. The 

overall goal of the In-Vehicle Display Icons and Other Information Elements project has been to provide the designers of 

these in-vehicle technologies with a set of design guidelines for in-vehicle display icons and other information elements. 

Specific objectives of this project were to: 

• Design and perform experimentation to select appropriate symbols for in-vehicle use, then analyze the resulting 

data to write final guidelines for in-vehicle symbols usage encompassing both current and future symbols. 

• Write preliminary, as well as empirically based, final guidelines. 

The key product of this project is a set of clear, concise, and user-centered human factors design guidelines for in-vehicle 

icon design. The guidelines address issues such as the legibility, recognition, interpretation, and evaluation of graphical 

and text-based icons and symbols. These guidelines provide IVIS developers with key information regarding the use and 

integration of existing and new visual symbols. In addition, the Icon IDEA software tool developed in this project has 

provided a real-time icon development and evaluation tool that, to-date, is receiving consistently positive reviews from the 

project’s working group members. This tool is entirely functional and ready to use, and should prove to be an invaluable 

aid and resource for icon design. 

17. Key Words 

Icons, In-Vehicle Display Design Guidelines, Auditory Messages, Icon 

Development, Icon Evaluation, Icon IDEA Software Tool 

18. Distribution Statement 

No restrictions. This document is available 

to the public through the National 

Technical Information Service, Springfield, 

VA 22161 

19. Security Classif. (of this report)

 NONE 

20. Security Classif. (of this page) 

 NONE 

21. No. of Pages 

 58 

22. Price 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
ii

SI* (MODERN METRIC) CONVERSION FACTORS 

APPROXIMATE CONVERSIONS TO SI UNITS

Symbol When You Know Multiply By To Find Symbol 

LENGTH 

in inches 25.4 millimeters mm 

ft feet 0.305 meters m 

yd yards 0.914 meters m 

mi miles 1.61 kilometers km 

AREA 

in2 square inches 645.2 square millimeters mm2

ft2 square feet 0.093 square meters m2

yd2 square yard 0.836 square meters m2

ac acres 0.405 hectares ha 

mi2 square miles 2.59 square kilometers km2

VOLUME 

fl oz fluid ounces 29.57 milliliters mL 

gal gallons 3.785 liters L 

ft3 cubic feet 0.028 cubic meters m3 

yd3 cubic yards 0.765 cubic meters m3 

NOTE: volumes greater than 1000 L shall be shown in m3

MASS 

oz ounces 28.35 grams g

lb pounds 0.454 kilograms kg

T short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t") 

TEMPERATURE (exact degrees) o

F Fahrenheit 5 (F-32)/9 Celsius oC 

or (F-32)/1.8 

ILLUMINATION 

fc foot-candles 10.76 lux lx 

fl foot-Lamberts 3.426 candela/m2 cd/m2

FORCE and PRESSURE or STRESS 

lbf poundforce 4.45 newtons N 

lbf/in2 poundforce per square inch 6.89 kilopascals kPa 

APPROXIMATE CONVERSIONS FROM SI UNITS 

Symbol When You Know Multiply By To Find Symbol 

LENGTH

mm millimeters 0.039 inches in 

m meters 3.28 feet ft 

m meters 1.09 yards yd 

km kilometers 0.621 miles mi 

AREA mm2

 square millimeters 0.0016 square inches in2 

m2 square meters 10.764 square feet ft2 

m2 square meters 1.195 square yards yd2 

ha hectares 2.47 acres ac 

km2 square kilometers 0.386 square miles mi2 

VOLUME 

mL milliliters 0.034 fluid ounces fl oz 

L liters 0.264 gallons gal 

m3 cubic meters 35.314 cubic feet ft3 

m3 cubic meters 1.307 cubic yards yd3 

MASS 

g grams 0.035 ounces oz

kg kilograms 2.202 pounds lb

Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T 

TEMPERATURE (exact degrees) o

C Celsius 1.8C+32 Fahrenheit oF 

ILLUMINATION 

lx lux 0.0929 foot-candles fc 

cd/m2 candela/m2 0.2919 foot-Lamberts fl

FORCE and PRESSURE or STRESS 

N newtons 0.225 poundforce lbf 

kPa kilopascals 0.145 poundforce per square inch lbf/in2

*SI is the symbol for th International System of Units. Appr e opriate rounding should be made to comply with Section 4 of ASTM E380. 

(Revised March 2003)
iii 

TABLE OF CONTENTS 

Page

EXECUTIVE SUMMARY .......................................................................................................... 1

CHAPTER 1: INTRODUCTION................................................................................................ 5

CHAPTER 2: SUMMARY OF PROJECT TASKS................................................................. 9

TASK A: PERFORM LITERATURE REVIEW ...................................................................... 9 

TASK B: CONDUCT PRELIMINARY ASSESSMENT OF VISUAL SYMBOLS ............. 11 

TASK C: DEVELOP WORKPLAN AND PRELIMINARY GUIDELINES FOR VISUAL 

SYMBOLS............................................................................................................... 16 

TASK D: DEVELOP WORKPLAN FOR FINAL GUIDELINES......................................... 22 

TASK E: EVALUATE VISUAL SYMBOLS.......................................................................... 28 

Experiment 3: Urgency and Annoyance of Auditory Alerts ............................................... 28 

Experiment 6: General versus Specific Icons: Implications for Driver Acceptance of IVIS 

Messages...................................................................................................... 31 

TASK F: DEVELOP FINAL GUIDELINES FOR IN-VEHICLE VISUAL SYMBOLS...... 36 

Develop Final Guidelines ..................................................................................................... 37

Develop the Icon IDEA Software......................................................................................... 37 

CHAPTER 3: CONCLUSIONS ................................................................................................ 45

APPENDIX A: PROJECT WORKING GROUP................................................................... 47

APPENDIX B: TECHNICAL REPORTS, PUBLICATIONS, AND PRESENTATIONS. 49

REFERENCES............................................................................................................................ 51
iv 

LIST OF FIGURES 

Page

Figure 1. The Flow of Project Activities ....................................................................................... 2 

Figure 2. The Flow of Project Activities (as presented in figure 1) .............................................. 6 

Figure 3. Flowchart of Task B Activities..................................................................................... 12 

Figure 4. Design Tool from Task B ............................................................................................ 13 

Figure 5. Flowchart of the Design Guidelines Development Process ........................................ 17 

Figure 6. Developing Individual Guidelines ............................................................................... 18 

Figure 7. Proposed Table of Contents for the Task C Preliminary Guidelines .......................... 19 

Figure 8. Sample of the Two-Page Format.................................................................................. 20 

Figure 9. Contents from Preliminary Guidelines Handbook ...................................................... 21 

Figure 10. Flow of Task D Activities .......................................................................................... 23

Figure 11. Examples of General and Specific Icons for Key In-Vehicle Message Categories ....32 

Figure 12. A Sample Page from the Phase 2b Response Booklet ............................................... 34 

Figure 13. IDEA Start-Up Screen................................................................................................ 39 

Figure 14. Results of the “View Icon Pictures” Function............................................................ 40 

Figure 15. Evaluation Scores for “Physical Features” for the Traffic Congestion Icon.............. 41

Figure 16. Comprehension Scores for the Traffic Congestion Icon .............................................42 

Figure 17. Design Recommendations for the Traffic Congestion Icon Reflecting the “Physical 

Features” Evaluation Results ..................................................................................... 43 
v 

LIST OF TABLES 

Page

Table 1. Summary of General Design Principles: Group I-IV Messages................................... 14 

Table 2. Candidate Research Issues Identified During the Early Phases of Task D. .................. 24 

Table 3. Research Issues Developed into Workplans.................................................................. 25 

Table 4. Table for Rating Each of the Key Issues ....................................................................... 26 

Table 5. Results of the Evaluations of the Six Workplans .......................................................... 27 

Table 6. Summary of Options A, B, C, and D............................................................................. 28 

Table 7. The Rank Ordered Means of Experiments 3 and 4 Ratings for Annoyance 

in the E-Mail Scenario .................................................................................................. 30 
vi 

LIST OF ACRONYMS 

ASR................................................................................................. Automatic Speech Recognition 

ATIS................................................................................. Advanced Traveler Information Systems 

CAS....................................................................................................Collision Avoidance Systems 

CVO .............................................................................................. Commercial Vehicle Operations 

DOT .................................................................................................. Department of Transportation 

FHWA.......................................................................................... Federal Highway Administration 

HUD...................................................................................................................... Head-Up Display 

IPE................................................................................................Information Processing Elements 

ISO .......................................................................... International Organization for Standardization 

ITS..............................................................................................Intelligent Transportation Systems 

IDEA.................................................................Interactive Development and Evaluation Assistant 

IVIS................................................................................................. In-Vehicle Information System 

MUTCD ..................................................................... Manual on Uniform Traffic Control Devices 

SAE..............................................................................................Society of Automotive Engineers 
1 

EXECUTIVE SUMMARY 

Recent and near-term development and deployment of Intelligent Transportation Systems (ITS) 

such as Advanced Traveler Information Systems (ATIS) and Collision Avoidance Systems 

(CAS) suggest that drivers will soon be faced with a host of new visual, auditory, and tactile 

information. In-Vehicle Information Systems (IVIS) technologies share the common goal of 

increasing public safety and reducing costs associated with accidents, collisions, and congestion. 

However, the distinctive and complex nature of IVIS devices suggests that these systems have 

the potential to further strain driver capabilities and that, if not carefully implemented, they may 

actually exacerbate existing traffic problems. Drivers have always had to time-share their 

attention between internal (e.g., speedometers) and external (e.g., traffic control devices) sources 

of information, but ITS technologies represent new frontiers for in-vehicle information systems. 

The overall goal of the “In-Vehicle Display Icons and Other Information Elements” project has 

been to provide designers of these in-vehicle technologies with a set of design guidelines for 

these icons and other information elements. Specific objectives of this project were to: 

• Design and perform experimentation to select appropriate symbols for in-vehicle use, 

then use the resulting data to write final guidelines for in-vehicle symbols usage 

encompassing both current and future symbols. 

• Write preliminary, as well as empirically based, final guidelines. 

IVIS devices are entering the automotive marketplace so quickly that many research issues 

associated with the design of in-vehicle visual symbols and other information elements have not 

been adequately addressed. Chief among these issues is the need to integrate multiple sources of 

IVIS messages that are presented to drivers and to prioritize these sources to reduce driver 

overload and maintain public safety. Also, auditory and tactile messages have not been 

addressed to the point where comprehensive design specifications for these systems can be 

confidently developed and communicated to the IVIS design community. Without the 

appropriate study and design guidance to aid and standardize their development, IVIS devices 

may present contradictory information to the driver, confuse the driver, overload or distract the 

driver, interfere with one another, violate driver expectations and responses, and lead to a 

decrease in driver safety. Therefore, it is critical that a comprehensive set of design guidelines 

for these systems is developed and shared with industry. 

The key product of this project is a set of clear, concise, and user-centered human factors design 

guidelines for in-vehicle icon design. The guidelines address issues such as the legibility, 

recognition, interpretation, and evaluation of graphical and text-based icons and symbols. These 

guidelines provide IVIS developers with key information regarding the use and integration of 

existing and new visual symbols. 

The flow of tasks in the project is shown in the following figure. As seen in the figure, the 

project consisted of a mix of analytical (tasks A and B), empirical (tasks D and E), and 

integrative (tasks C and F) activities. 
2 

Figure 1. The Flow of Project Activities 

As noted above, the overall goal of the In-Vehicle Display Icons and Other Information Elements

project has been to provide the designers of in-vehicle technologies with a set of design 

guidelines for in-vehicle display icons and other information elements. The final design 

guidelines provided in Volume I of this project have clearly achieved this goal. These clear, 

relevant, and easy-to-use guidelines provide up-to-date information on a number of topics critical 

to icon development and evaluation. 

Task C: Develop Work

Plan and Preliminary

Guidelines for

Visual Symbols

Task D: Develop

Work Plan for

Final Guidelines

Task E: Visual

Symbol Evaluation

Task F: Develop

Final Guidelines

for In-Vehicle

Visual Symbols

Task G: Prepare

Final Reports

Task A: Perform

Literature Review

Task B: Conduct

Preliminary

Assessment of 

Visual Symbols

Task C: Develop Work

Plan and Preliminary

Guidelines for

Visual Symbols

Task D: Develop

Work Plan for

Final Guidelines

Task E: Visual

Symbol Evaluation

Task F: Develop

Final Guidelines

for In-Vehicle

Visual Symbols

Task G: Prepare

Final Reports

Task A: Perform

Literature Review

Task B: Conduct

Preliminary

Assessment of 

Visual Symbols

Task C: Develop Work

Plan and Preliminary

Guidelines for

Visual Symbols

Task D: Develop

Work Plan for

Final Guidelines

Task E: Visual

Symbol Evaluation

Task F: Develop

Final Guidelines

for In-Vehicle

Visual Symbols

Task G: Prepare

Final Reports

Task A: Perform

Literature Review

Task B: Conduct

Preliminary

Assessment of 

Visual Symbols
3 

Much of the impetus behind the initial conceptualization of this project can be summed up by 

going back to two of the conclusions from the project’s task A report: 

1. The lack of guidelines and standards for icons has resulted in design by consensus, a 

lack of scientific rigor in icon development, and multiple icons for the same 

messages. 

2. Existing literature and standards provide little guidance for the design of new icons 

for IVIS devices. 

In short, the transportation system design community—and, indeed, the larger 

electronics/computer industry—has not had the benefit of a single information source that 

provided clear, relevant, and useful guidance for icon design. The final guidelines produced in 

this project therefore fill a critical gap in the transportation human factors literature. 

In addition, the Icon Interactive Development and Evaluation Assistant (Icon IDEA or IDEA) 

software tool developed in this project has provided a real-time icon development and evaluation 

tool that, to date, is receiving consistently positive reviews from the project’s working group 

members. This tool is entirely functional and ready to use, and should prove to be an invaluable 

aid and resource for icon design. Also, the technical reports, conference papers, and conference 

presentations developed during this project provide a permanent record on a number of 

substantive issues related to icon design that may not yet be incorporated into either the final 

design guidelines or the IDEA software tool. 

5 

CHAPTER 1: INTRODUCTION 

Recent and near-term development and deployment of Intelligent Transportation Systems (ITS) 

such as Advanced Traveler Information Systems (ATIS) and Collision Avoidance Systems 

(CAS) suggest that drivers will soon be faced with a host of new visual, auditory, and tactile 

information. In-Vehicle Information Systems (IVIS) technologies share the common goal of 

increasing public safety and reducing costs associated with accidents, collisions, and congestion. 

However, the distinctive and complex nature of IVIS devices suggests that these systems have 

the potential to further strain driver capabilities and that, if not carefully implemented, they may 

actually exacerbate existing traffic problems. Drivers have always had to time-share their 

attention between internal (e.g., speedometers) and external (e.g., traffic control devices) sources 

of information, but ITS technologies represent new frontiers for in-vehicle information systems. 

The overall goal of the In-Vehicle Display Icons and Other Information Elements project has 

been to provide designers of these in-vehicle technologies with a set of design guidelines for 

these icons and other information elements. Specific objectives of this project were to: 

• Design and perform experimentation to select appropriate symbols for in-vehicle use, 

then use the resulting data to write final guidelines for in-vehicle symbols usage 

encompassing both current and future symbols. 

• Write preliminary, as well as empirically based, final guidelines. 

IVIS devices are entering the automotive marketplace so quickly that many research issues 

associated with the design of in-vehicle visual symbols and other information elements have not 

been adequately addressed. Chief among these issues is the need to integrate multiple sources of 

IVIS messages that are presented to drivers and to prioritize these sources to reduce driver 

overload and maintain public safety. Also, auditory and tactile messages have not been 

addressed to the point where comprehensive design specifications for these systems can be 

confidently developed and communicated to the IVIS design community. Without the 

appropriate study and design guidance to aid and standardize their development, IVIS devices 

may present contradictory information to the driver, confuse the driver, overload or distract the 

driver, interfere with one another, violate driver expectations and responses, and lead to a 

decrease in driver safety. Therefore, it is critical that a comprehensive set of design guidelines 

for these systems is developed and shared with industry. 

The key product of this project is a set of clear, concise, and user-centered human factors design 

guidelines for in-vehicle icon design. The guidelines address issues such as the legibility, 

recognition, interpretation, and evaluation of graphical and text-based icons and symbols. These 

guidelines provide IVIS developers with key information regarding the use and integration of 

existing and new visual symbols. 

The flow of tasks in the project is shown in figure 2. As seen in the figure, the project consisted 

of a mix of analytical (tasks A and B), empirical (tasks D and E), and integrative (tasks C and F) 

activities. 
6 

Figure 2. The Flow of Project Activities (as presented in figure 1) 

In broad terms, the analytical activities (tasks A and B) provided a review of current in-vehicle 

icon use and designer needs for human factors information for in-vehicle icons; empirical 

activities (tasks D and E) consisted of experiments to address high-priority research gaps in the 

icon design literature; and integrative activities (tasks C and F) included the development of both 

preliminary and final human factors design guidelines for in-vehicle icons. 

A key element of the project has been the participation of a project working group, consisting of 

transportation and computing professionals from automotive manufacturers, in-vehicle systems 

vendors, academia, software companies, and the ITS and human factors communities. A full list 

Task C: Develop Work

Plan and Preliminary

Guidelines for

Visual Symbols

Task D: Develop

Work Plan for

Final Guidelines

Task E: Visual

Symbol Evaluation

Task F: Develop

Final Guidelines

for In-Vehicle

Visual Symbols

Task G: Prepare

Final Reports

Task A: Perform

Literature Review

Task B: Conduct

Preliminary

Assessment of 

Visual Symbols

Task C: Develop Work

Plan and Preliminary

Guidelines for

Visual Symbols

Task D: Develop

Work Plan for

Final Guidelines

Task E: Visual

Symbol Evaluation

Task F: Develop

Final Guidelines

for In-Vehicle

Visual Symbols

Task G: Prepare

Final Reports

Task A: Perform

Literature Review

Task B: Conduct

Preliminary

Assessment of 

Visual Symbols

Task C: Develop Work

Plan and Preliminary

Guidelines for

Visual Symbols

Task D: Develop

Work Plan for

Final Guidelines

Task E: Visual

Symbol Evaluation

Task F: Develop

Final Guidelines

for In-Vehicle

Visual Symbols

Task G: Prepare

Final Reports

Task A: Perform

Literature Review

Task B: Conduct

Preliminary

Assessment of 

Visual Symbols
7 

of the past and current working group for this project is provided in appendix A. The working 

group has helped to ensure that design guidelines resulting from this project conform to icon 

designers’ specific needs with respect to content, organization, and format. Specific activities of 

the working group have been to: 

• Participate in regular teleconferences to discuss project status, deliverables, and future 

plans. 

• Review project reports and provide feedback. 

• Provide relevant information and documents to the project team. 

• Identify the needed content, organization, and format for the guidelines. 

• Serve as reviewers for the in-progress guidelines. 

• Provide more formal evaluation of the draft guidelines handbook. 

This report provides one project deliverable associated with task G: “Prepare Final Reports.” The 

purpose of task G is to provide final documentation of the objectives, methods, and results from 

this project. The remainder of this report is presented in two sections. The “Summary of Project 

Tasks” section describes the objectives, conduct, and results from tasks A–F of this project. The 

“Results and Conclusions Section” summarizes the project’s key products and benefits. 

9 

CHAPTER 2: SUMMARY OF PROJECT TASKS 

This section of this report summarizes the following project tasks: 

• Task A: Perform Literature Review. 

• Task B: Conduct Preliminary Assessment of Visual Symbols. 

• Task C: Develop Workplan and Preliminary Guidelines for Visual Symbols. 

• Task D: Develop Workplan for Final Guidelines. 

• Task E: Evaluate Visual Symbols. 

• Task F: Develop Final Guidelines for In-Vehicle Visual Symbols. 

TASK A: PERFORM LITERATURE REVIEW 

The purpose of task A was to conduct a review of relevant symbols and research, including the 

use of symbols by manufacturers and after-market vendors for existing and planned in-vehicle 

systems. The methodology employed included examining articles collected as part of the 

previous guideline development efforts, conducting extensive database searches, and accessing 

the Internet to gather information regarding the most current use of symbols in existing and 

future in-vehicle information systems. More than 200 articles, several books, and more than 100 

Web sites were found via this methodology.

Once all of the literature was gathered, it was reviewed to determine its relevance to the current 

project. Specifically, attention was given to including information relevant to: 

• The definition of an icon, design and evaluation of symbols, and models of symbol 

recognition and understanding. 

• The effect of symbol mode (e.g., visual, auditory, tactile). 

• The effects of symbol content and format. 

• Driver information needs for in-vehicle messages (ATIS and CAS). 

• Current use of symbols and icons by manufacturers and after-market vendors. 

• Evaluation practices for icons and symbols. 

• Existing standards and guidelines (e.g., Society of Automotive Engineers (SAE), 

International Organization for Standardization (ISO), and the Manual on Uniform Traffic 

Control Devices (MUTCD)). 

The review comprehensively captured the status of icon/symbol research and applications and, 

most importantly, provided a solid foundation for subsequent tasks in this project. The following 

conclusions emerged from the review and analyses of the literature for icon and symbol research 

and current applications: 
10 

The lack of guidelines and standards for icons has resulted in design by consensus, a lack of 

scientific rigor in icon development, and multiple icons for the same messages. A number of 

sources for existing transportation symbols and icons were found during this literature review. 

They provided symbols and icons for numerous transportation applications (i.e., road signs, 

traveler information, warnings, etc.). However, during our investigation of these sources, it 

became clear that the process of developing and choosing icons is very subjective. Icons are 

frequently incorporated into system designs on the basis of consensus, opinions, and aesthetic 

preferences of the system development team. While such a process can result in an effective 

icon (as evidenced by the many effective icons in use in in-vehicle devices), it also runs the risk 

of producing unclear and ineffective icons. 

Existing literature and standards provide little guidance for the design of new icons for IVIS 

devices. The majority of literature relevant to the design of icons can be placed into one of two 

categories: (1) a general discussion on the development of symbols (i.e., what they are, why they 

should be used, and how they work), or (2) proposed methods for the evaluation of symbols and 

demonstrations of these evaluations using existing symbols. Although the existing literature 

helps provide background information necessary to understand how we derive meaning from 

icons and symbols, it does little to aid in the development of design guidelines for new icons. 

General design principles for icon design are sufficient to avoid development of a “bad” icon, 

but are not specific enough to support development of the “best” icon. The review and 

integration activities suggested that a number of general principles for icon design are available 

to IVIS developers. These include the structure, shape, and color of icons. However, for several 

reasons, these guidelines are not sufficient to support the development of optimum, or “best,” 

icons. First, these principles, like many human factors guidelines materials, are not specific 

enough. For example, they identify how icon shape can affect comprehension. But how do 

designers select a shape to begin with? How does a designer start with “givens,” such as a 

driving context and driver information needs, and identify a shape that matches these “givens?” 

Second, it is difficult for designers to know how to apply the principles in any given situation. 

For example, when is the structure of an icon more important than its shape? Are there times 

when the conspicuity of an icon (such as a collision avoidance warning) is more important than 

the details of its physical design? How do color and shape interact to impact the driver’s 

interpretation of an icon or symbol? Third, existing principles do not provide adequate guidance 

on issues such as how to “match” an icon with its associated message. In this regard, available 

principles for icon design do not generally address the importance of information elements (the 

purpose of the icon, such as alert, inform, plan, and decide) to the driver’s accurate interpretation 

and effective use of icons. Thus, there are still considerable gaps between the needs of icon 

developers and the availability of human factors design information. 

Development of new icons and symbols for in-vehicle devices will require iterative testing and 

evaluation; existing test and evaluation methods provide sufficient scientific rigor for future 

evaluations of icons and symbols. The interpretation and ultimate utility of icons and symbols 

depend on the relationship, or “match,” between the message and the graphic elements selected 

to convey the message. Unfortunately, there is no immediate or obvious method of determining 

this “match,” given the variability associated with IVIS devices, IVIS messages, and drivers. 
11 

Therefore, good icon design requires development of a range of candidate icons and, equally 

important, iterative testing and evaluation of these candidate icons. 

Despite industry concerns over the utility and relevance of human factors design guidelines, 

rigorous and proven methods for design guideline development exist and will be used in tasks 

C and F of this project. Designers of advanced automotive displays have criticized many 

existing human factors reference materials for being too wordy, too general, and too hard to 

understand, and have requested guidance that is concise, specific, and clear.(1) In particular, 

three challenges are associated with the development of human factors design guidelines for 

in-vehicle icons and symbols: (1) the lack of human factors design criteria; (2) the development 

of selection criteria for data sources used to produce guidelines; and (3) variability in the user 

population of human factors design guidelines.(1,2)

Despite these challenges, a number of successful design guidelines for ATIS, CAS, and other 

in-vehicle devices have been developed. (3,4) The general procedures used in these efforts were 

used to guide design guideline development activities in tasks C and F of the current project. 

TASK B: CONDUCT PRELIMINARY ASSESSMENT OF VISUAL SYMBOLS 

Task B in this project served two very useful purposes. First, it identified credible procedures, 

heuristics, and principles for the joint use of visual, auditory, and tactile information to present 

in-vehicle messages. The task B report documented the underlying rationale for selection of 

display modality by reviewing the relevant literature and assessing the current state of 

knowledge. Second, task B defined message characteristics that should guide symbol design. 

Defining these characteristics and their interactions helps to identify design tradeoffs and 

provides the basis for future design guidelines and tools. In summary, task B provided design 

guidance for the joint use of visual, auditory, and tactile information presentation and provided a 

foundation for future design tools that could assist designers in specifying icon design for invehicle information technologies, particularly as they relate to ATIS. 

The process used to identify design requirements of in-vehicle icons and IVIS messages in task 

B included seven basic steps: 

1. Generate a list of IVIS messages. 

2. Conduct review of literature relevant to sensory modality. 

3. Evaluate IVIS messages to determine sensory modality. 

4. Define messages according to their contextual characteristics and information processing 

elements (IPEs). 

5. Cluster messages according to contextual characteristics. 

6. Group clusters to identify general design categories. 

7. Examine IPEs and design tradeoffs within each cluster and category. 

Figure 3 shows the order in which these steps were completed and their interrelationships. From 

this flow diagram, we are able to see how the results of each step were used to develop the final 

product design requirements and tradeoffs for categories of IVIS messages. 
12 

Figure 3. Flowchart of Task B Activities 

One of the first steps completed during task B was to review the literature for information related 

to the development of rules for selecting display modes. An examination of these rules led to the 

design of several decision aids that would assist designers in the selection of a sensory modality 

for displaying different pieces of in-vehicle information. Each decision aid was tested using 

several candidate information elements until a final viable approach could be determined. The 

final approach was then refined through additional informal testing and analysis. The final 

design tool can be seen in figure 4. 

The results of applying the design tool suggest that: (1) the visual modality should be used to 

display more complex information that does not require the driver’s immediate response and 

may need to be referred to at a later time; (2) the auditory modality should be used to present 

simple information that is extremely urgent or critical messages that require the driver’s 

attention; (3) a combination of the auditory and visual modalities should be used to present 

information that is both complex and relatively urgent but is too complex to be presented via 

simple tone or verbal message; and (4) the tactile modality did not appear to be a viable option 

for presenting any IVIS messages that had been identified. 

Define Messages According

to Their Information

Processing Elements

Define Messages According

to Their Information

Processing Elements

Evaluate IVIS Messages to

Determine Sensory Modality

Evaluate IVIS Messages to

Determine Sensory Modality

Group Clusters to Identify

General Design Categories

Group Clusters to Identify

General Design Categories

Generate List of

IVIS Messages

Generate List of

IVIS Messages

Conduct Review of Literature

Relevant to Sensory Modality

and Develop Sensory

Modality Design Tool

Conduct Review of Literature

Relevant to Sensory Modality

and Develop Sensory

Modality Design Tool

Define Messages

According to

Contextual Characteristics

Define Messages

According to

Contextual Characteristics

Cluster Messages

According to

Contextual Characteristics

Cluster Messages

According to

Contextual Characteristics

Define Messages According

to Their Information

Processing Elements

Define Messages According

to Their Information

Processing Elements

Evaluate IVIS Messages to

Determine Sensory Modality

Evaluate IVIS Messages to

Determine Sensory Modality

Group Clusters to Identify

General Design Categories

Group Clusters to Identify

General Design Categories

Generate List of

IVIS Messages

Generate List of

IVIS Messages

Conduct Review of Literature

Relevant to Sensory Modality

and Develop Sensory

Modality Design Tool

Conduct Review of Literature

Relevant to Sensory Modality

and Develop Sensory

Modality Design Tool

Define Messages

According to

Contextual Characteristics

Define Messages

According to

Contextual Characteristics

Cluster Messages

According to

Contextual Characteristics

Cluster Messages

According to

Contextual Characteristics
13 

Figure 4. Design Tool from Task B 

The next step was to provide a more solid basis for design by defining the messages according to 

their contextual characteristics and the information processing elements they supported. Once 

this was complete, a cluster analysis was conducted; it identified 12 unique clusters of IVIS 

messages. To organize these clusters for interpretation, a further analysis identified 4 groups of 

clusters based on the center of each of the 12 clusters. Table 1 summarizes each of the message 

groups and the design requirements that they support. 

Visual

Auditory

Tactile

Visual

Auditory

Tactile

Visual

Auditory

Tactile

Visual

Auditory

Tactile

Visual

Auditory

Tactile

Very Low Medium High Very

Low High

4

1

1

1

4

4

3

4

4

5

1

0

3

5

5

3

2

2

2

3

2

3

3

1

4

2

0

3

4

1

2

3

3

3

2

0

3

2

0

3

3

0

3

3

0

1

4

4

4

1

0

4

1

0

3

4

1

4

2

0

1

5

5

5

1

0

5

1

0

3

5

5

5

1

0

Visual Auditory Tactile

sum sum sum

Visual Auditory Tactile

1. What is the degree of

urgency of the message?

2. To what degree might

the message be referred

to again later?

3. What is the overall

level of complexity of

the message?

4. To what degree does

the message deal with a

future action in time?

5. To what degree does

the message refer to

locations in space?

IVIS Message:

Other Relevant Factors:

Questions:

Visual

Auditory

Tactile

Visual

Auditory

Tactile

Visual

Auditory

Tactile

Visual

Auditory

Tactile

Visual

Auditory

Tactile

Very Low Medium High Very

Low High

4

1

1

1

4

4

3

4

4

5

1

0

3

5

5

3

2

2

2

3

2

3

3

1

4

2

0

3

4

1

2

3

3

3

2

0

3

2

0

3

3

0

3

3

0

1

4

4

4

1

0

4

1

0

3

4

1

4

2

0

1

5

5

5

1

0

5

1

0

3

5

5

5

1

0

Visual Auditory Tactile

sum sum sum

Visual Auditory Tactile

1. What is the degree of

urgency of the message?

2. To what degree might

the message be referred

to again later?

3. What is the overall

level of complexity of

the message?

4. To what degree does

the message deal with a

future action in time?

5. To what degree does

the message refer to

locations in space?

IVIS Message:

Other Relevant Factors:

Questions:
14 

Table 1. Summary of General Design Principles: Group I-IV Messages 

TYPE OF MESSAGE GENERAL DESIGN 

PRINCIPLES SAMPLE MESSAGES

Group 

I 

High-priority driving 

messages: relatively critical, 

high urgency messages that are 

tightly linked to the driving 

task. 

• Highly salient and compelling. 

• Induce a fast response. 

• Distinguishable. 

• Place near the driver’s center 

of attention. 

• Warning indicator (backing 

device). 

• Interchange ahead. 

• School bus stopped ahead. 

Group 

II 

Medium-priority dependent 

messages: moderately urgent 

and critical messages that are 

presented either 

simultaneously or sequentially 

with other messages. 

• Less salient, more subtle alerts. 

• An object display or map 

should be used to integrate the 

messages and promote 

comparisons and information 

integration. 

• Shortest route option. 

• Distance and time to turn. 

• System on and functioning 

(driver monitoring). 

Group 

III 

Non-driving independent 

message: no relation to the 

driving task and are unlikely to 

be presented either 

simultaneously or sequentially 

with other messages. 

• Salient, compelling, and 

recognizable. 

• Easy to discriminate. 

• Support comparisons and 

relate status to norms or 

expectations. 

• Place outside the focus of 

driver’s attention. 

• Inform driver of needed 

warranty services due. 

• System failure (all other 

Collision Avoidance systems). 

• Message acknowledged or 

received. 

Group 

IV 

Low-priority messages: the 

most common type of message 

and are neither critical nor 

urgent. 

• Easily discriminated. 

• Compelling, recognizable. 

• Highlight status changes and 

afford action. 

• Support comparisons and 

relate status to norms or 

expectations. 

• Remaining balance in toll 

account. 

• Total time to complete travel 

(identify). 

• Vacancy status of hotels along 

route. 

Devising these design tools and analyzing the current list of relevant IVIS messages resulted in 

the following conclusions in task B: 

 

A review of existing literature regarding visual, auditory, and tactile information presentation 

provided numerous general principles for modality selection, which was the basis for an 

effective sensory modality design tool. A review of both general human factors research and 

more recent research directly related to ATIS and Collision Avoidance System (CAS) displays 

provided a number of general principles and heuristics regarding different display modes (visual, 

auditory, and tactile). Summarizing these rules and categorizing them according to the design 

decisions they supported led to a design tool that would direct designers toward the most 

appropriate sensory modality choice. 

Results of applying the sensory modality design tool indicated that the visual modality should be 

used for presenting complex messages that are less urgent and critical and that the driver may 
15 

need to refer to at another point during the drive. Auditory messages were identified as those 

that have some type of alerting property: They provide the driver with urgent and critical 

information that is simple enough to be presented via an auditory tone or a brief verbal message. 

A combination of the visual and auditory modalities should be used for messages that require the 

driver’s attention but are too complicated to be presented by an auditory message or will be 

referred to again later in the drive. The tactile modality was not identified as appropriate for 

displaying any of the 273 candidate IVIS messages. However, it is important to note that in a 

few instances tactile displays have been shown to be useful (i.e., the shaker stick on an aircraft); 

therefore, they should not be ignored as a potential display modality. 

Classifying IVIS messages according to ITS technologies and general functions is not 

sufficient for providing effective design guidelines. Classifying IVIS messages according to 

general IVIS capabilities and functions does catalog the range of messages and show similarities 

based on the IVIS capabilities they are meant to support. However, this organizing approach 

does not reflect several important characteristics of IVIS messages that can influence design 

guidelines. Effective design guidelines and design tools require a description of IVIS messages 

that reflects message characteristics that influence driver comprehension and response. Defining 

messages according to their driver-relevant characteristics provides a more solid basis for design. 

Understanding the driving context under which IVIS messages are presented is critical for 

successful design guideline development. Successful presentation of IVIS messages using icons 

depends on creating a message appropriate to its driving context. This report defines the context 

of IVIS messages using four dimensions that capture key elements of how context aids the 

interpretation of messages. Specifically, message urgency and criticality identify the 

consequences of not responding to a message in a timely manner. In contrast, dimensions such 

as the link to the driving task and the independence of the message identify opportunities to 

enhance the interpretation of a message by providing additional cues. Grouping the messages 

according to these four dimensions provides a first step in defining the requirements for 

integrating IVIS messages into a coherent set. 

The Information Processing Elements (IPEs) associated with an IVIS message can be used 

successfully to develop the design guidelines that consider the perceptual, memory, and motor 

control limits of the driver. This report identifies nine different IPEs: alert, identify, search, 

evaluate, plan, decide, coordinate, control, and monitor. Together, these nine elements describe 

the range of information processing activities supported by IVIS messages. Each element 

supports a different set of design requirements that complement those identified by contextual 

characteristics. Identifying the elements associated with each individual message informs the 

designer about design decisions and tradeoffs that will need to be made for several different 

design parameters. 

The cluster analysis technique provides a powerful tool to focus future analyses on a 

meaningful subset of possible combinations of contextual characteristics and IPEs. The 

cluster analysis proved to be a very effective technique in the preliminary assessment of visual 

symbols. The original 4 contextual characteristics (with 5 levels within each), combined with the 

9 IPEs, yield 5,626 unique combinations. This presents designers with a dizzying array of 

tradeoffs to make when designing in-vehicle icons and other information elements. This 
16 

approach uses a tradeoff analysis that serves to focus future design guideline development 

efforts. Using statistical clustering techniques, the preliminary analysis identified four general 

message groups that describe 12 message clusters. These groups and their corresponding 

clusters identify important combinations of contextual characteristics and IPEs that describe the 

range of IVIS messages. Preliminary consideration of these groups and clusters suggests that 

each cluster and group has unique design requirements for in-vehicle messages. The initial 

description of these design requirements and their associated tradeoffs provides the basis for 

more specific design guidelines and practical design tools. 

The tools and decision aids developed as part of task B provided the project team with a solid 

analytical foundation to begin guideline development in task C of this project. Combining the 

information obtained by identifying: 

1. The contextual characteristics of a message. 

2. The IPEs that the message supports. 

3. The results of applying the sensory modality decision tool, which provides the IVIS 

designer with a relatively comprehensive list of requirements and parameters that should 

be considered during the design of in-vehicle icons and other information elements. 

The initial description of these design requirements and associated tradeoffs provided the basis 

for more refined design guidelines developed as part of task C of this project. 

A key challenge associated with task C would be to integrate the information provided in the 

task B report and develop clear, relevant, and easy-to-use design guidelines for in-vehicle 

icons. The task B report established some important relationships among IVIS messages, 

display modality, the driving context, and IPEs of the IVIS messages. Understanding these 

relationships is necessary, but not sufficient, to support the development of clear, relevant, and 

easy-to-use human factors design guidelines for in-vehicle icons and other information elements. 

During task C, the project team would need to integrate the information presented in this report 

and the task A report with specific design options for icon design such as background, symbol, 

border, symbol elements, and text labels. 

TASK C: DEVELOP WORKPLAN AND PRELIMINARY GUIDELINES FOR 

VISUAL SYMBOLS 

The overall goal of task C was to produce a set of preliminary human factors design guidelines 

for in-vehicle visual symbols. Toward this end, task C activities included three interrelated 

subtasks: 

1. Developing a workplan for the preliminary guidelines. 

2. Developing the preliminary guidelines. 

3. Developing a working paper that explored information and symbology usage issues. 

Each of these task C subtasks is discussed in more detail below. 
17 

Developing a workplan for the preliminary guidelines. The development of the Human 

Factors Design Guidelines for In-Vehicle Symbols and Other Information Elements was directed 

toward answering the following general question: What is the relationship between various 

symbol design parameters and a driver’s ability to use automotive displays effectively and 

comfortably given variations in operating conditions, driving tasks, and driver demographics? In 

the human factors community, it is widely acknowledged that the majority of human 

factors/human performance research findings cannot be easily generalized to complex, realworld systems. This is often because such research is situation-specific (i.e., the results are 

highly dependent upon the environment, context, experimental task, subject demographics, etc. 

that identify a given study). Nonetheless, legitimate and much needed generalizations of the data 

are possible through careful and thoughtful integration of existing research findings. 

Specifically, development of the guidelines was expected to include several essential elements: 

(1) a comprehensive database of existing information sources; (2) knowledge of the automotive 

display design environment, including tradeoffs and constraints; (3) analytical activities, 

including a clear definition of the criteria that will be used to determine the quality and 

applicability of data sources; (4) a willingness to apply experience and judgment to the 

development of human factors design guidelines; and (5) methods of presenting the design 

guidelines in a manner compatible with the user-community’s needs and desires for the 

guidelines. 

Figure 5 shows the overall design guideline development process presented in the task C 

workplan, while figure 6 shows the process for developing individual guidelines. 

Figure 5. Flowchart of the Design Guidelines Development Process 

1. Select Initial Set of Data

Sources 1. Select Initial Set of Data

Sources

2. Determine the Quality and

Applicability of Data

Sources

2. Determine the Quality and

Applicability of Data

Sources

3. Select Final Data Sources 3. Select Final Data Sources

4. Formulate the Design

Guideline 4. Formulate the Design

Guideline

5. Provide Relative Accuracy

and Level-of-Confidence

Information

5. Provide Relative Accuracy

and Level-of-Confidence

Information

STEP INPUTS/CRITERIA/CONSIDERATIONS

Is the source generally relevant?

Contractor libraries and resources, university collections,

online databases.

How valid and generalizable is the source?

Source type, intended application, amount of empirical

support, study setting, independent and dependent variables,

consistency with comparable sources, internal and external

validity.

Should the data source be used?

Level-of-evidence heuristic and usability/precision tradeoffs.

Quality and applicability evaluation.

What was the relative contribution of empirical data and

expert judgment?

Assign rating using the 4-star rating system.

What was the nature and amount of source data?

Develop supporting rationale and identify special design

considerations.

What should the design guideline be?

Integrative review and analysis of data sources.

Heuristics, experience, and judgment.

Application of display modality selection tool.

Consideration of driving context and IPEs.

1. Select Initial Set of Data

Sources 1. Select Initial Set of Data

Sources

2. Determine the Quality and

Applicability of Data

Sources

2. Determine the Quality and

Applicability of Data

Sources

3. Select Final Data Sources 3. Select Final Data Sources

4. Formulate the Design

Guideline 4. Formulate the Design

Guideline

5. Provide Relative Accuracy

and Level-of-Confidence

Information

5. Provide Relative Accuracy

and Level-of-Confidence

Information

STEP INPUTS/CRITERIA/CONSIDERATIONS

Is the source generally relevant?

Contractor libraries and resources, university collections,

online databases.

How valid and generalizable is the source?

Source type, intended application, amount of empirical

support, study setting, independent and dependent variables,

consistency with comparable sources, internal and external

validity.

Should the data source be used?

Level-of-evidence heuristic and usability/precision tradeoffs.

Quality and applicability evaluation.

What was the relative contribution of empirical data and

expert judgment?

Assign rating using the 4-star rating system.

What was the nature and amount of source data?

Develop supporting rationale and identify special design

considerations.

What should the design guideline be?

Integrative review and analysis of data sources.

Heuristics, experience, and judgment.

Application of display modality selection tool.

Consideration of driving context and IPEs.

1. Select Initial Set of Data

Sources 1. Select Initial Set of Data

Sources

2. Determine the Quality and

Applicability of Data

Sources

2. Determine the Quality and

Applicability of Data

Sources

3. Select Final Data Sources 3. Select Final Data Sources

4. Formulate the Design

Guideline 4. Formulate the Design

Guideline

5. Provide Relative Accuracy

and Level-of-Confidence

Information

5. Provide Relative Accuracy

and Level-of-Confidence

Information

STEP INPUTS/CRITERIA/CONSIDERATIONS

Is the source generally relevant?

Contractor libraries and resources, university collections,

online databases.

How valid and generalizable is the source?

Source type, intended application, amount of empirical

support, study setting, independent and dependent variables,

consistency with comparable sources, internal and external

validity.

Should the data source be used?

Level-of-evidence heuristic and usability/precision tradeoffs.

Quality and applicability evaluation.

What was the relative contribution of empirical data and

expert judgment?

Assign rating using the 4-star rating system.

What was the nature and amount of source data?

Develop supporting rationale and identify special design

considerations.

What should the design guideline be?

Integrative review and analysis of data sources.

Heuristics, experience, and judgment.

Application of display modality selection tool.

Consideration of driving context and IPEs.
18 

Figure 6. Developing Individual Guidelines 

The preliminary design guidelines were expected to contain a similar content structure as that 

used in the Advanced Traveler Information Systems/Commercial Vehicle Operations 

(ATIS/CVO) design guidelines produced for the Federal Highway Administration (FHWA). The 

final content was expected to be determined after consultation with FHWA and the project 

working group members. Figure 7 summarizes the proposed table of contents for the 

preliminary guidelines. 

For the preliminary design guidelines, a two-page presentation format was chosen to satisfy the 

conflicting requirements for having simple graphics versus more complex, detailed descriptions 

of “real world” design situations. A schematic example of the two-page format presented in the 

original workplan is shown in figure 8. The left-hand page presents the graphic data and simple 

supporting text, while the right-hand page provides the more detailed information that a human 

factors practitioner is likely to require in performing his or her design tasks. 

Guideline

Topics

Remaining?

Select Topic

from

Approved

Outline

Conduct

Integrative

Review of Data

Sources and

Research

Findings

Prepare

Supporting

Text

Prepare

Graphics

or

Schematic

Examples

Formulate the

Draft Design

Guideline

Conduct

Project Team

Review

START

Publish 

Guidelines

YES

NO

YES

NO

Determine

Guideline

Information

Conduct Analytical

Activities, Including

Use of Heuristics

and Expert Judgment

Assign

“Bar”

Rating

Revision

Required?

Application

of Design

Tools, as

Needed

Guideline

Topics

Remaining?

Select Topic

from

Approved

Outline

Conduct

Integrative

Review of Data

Sources and

Research

Findings

Prepare

Supporting

Text

Prepare

Graphics

or

Schematic

Examples

Formulate the

Draft Design

Guideline

Conduct

Project Team

Review

START

Publish 

Guidelines

YES

NO

YES

NO

Determine

Guideline

Information

Conduct Analytical

Activities, Including

Use of Heuristics

and Expert Judgment

Assign

“Bar”

Rating

Revision

Required?

Application

of Design

Tools, as

Needed
19 

Table of Contents for Preliminary Design Guidelines

Chapter 1 How to Use the Design Guidelines 

- Overview of the Handbook Organization 

- Explanation of the Guideline Format 

Chapter 2 Overview of IVIS Subsystems and Functions 

- Routing and Navigation 

- Motorist Services 

- Augmented Signage 

- Safety/Warning 

- CVO-Specific 

- Global Positioning System-Related 

- Collision Avoidance 

Chapter 3 Guidelines for General Issues and Icon Design 

Chapter 4 Icon Legibility Guidelines 

Chapter 5 Icon Recognition Guidelines 

Chapter 6 Icon Interpretation Guidelines 

Chapter 7 Routing and Navigation Guidelines 

Chapter 8 Motorist Services Guidelines 

Chapter 9 Augmented Signage Guidelines 

Chapter 10 Safety/Warning Guidelines 

Chapter 11 CVO-Specific Guidelines 

Chapter 12 Collision Avoidance Guidelines 

Chapter 13 Guidelines for Icon Evaluation Techniques 

Chapter 14 Relevant DOT, SAE, ISO Documents 

Chapter 15 List of Icon Websites 

Chapter 16 Design Tools 

Chapter 17 List of Equations 

Chapter 18 Glossary 

Chapter 19 References 

Chapter 20 Extended Bibliography 

Chapter 21 Scope and Limitations of These Guidelines 

Chapter 22 About these Human Factors Design Guidelines 

- Role of Human Factors in IVIS Design 

- Summary of Project 

- How the Guidelines were Formulated 

Chapter 23 Index 

Figure 7. Proposed Table of Contents for the Task C Preliminary Guidelines 
20 

Figure 8. Sample of the Two-Page Format 

The contractor’s previous experience in developing human factors design guidelines provided us 

with a number of heuristics regarding “ideal” presentation formats. These heuristics included: 

• The handbook should, as much as possible, present its information in graphic form. 

• The preferred graphic is a figure, chart, or graph. Generally, representational figures are 

the most useful. 

• Text information should also be included, but its primary functions should be to help 

explain the graphics. 

• Text information should always be kept brief, perhaps limited to one- or two-line 

recommendations. 

• Text information should be highly organized and tightly structured within each topic. 

• When making design recommendations, references to original source material should be 

included. 

• When possible, the implications of the design objective for human performance should 

be specified. 

• When recommendations are made, they should be highly specific. 

• Recommendations should not just be given in absolute terms, but should specify a range 

of acceptable values, if appropriate. 

DETERMINING THE APPROPRIATE LUMINANCE UNIFORMITY WITHIN AN ICON

Introduction: Luminance uniformity refers to the consistency of luminance values across an icon. Moderate

nonuniformities in luminance may only lead to the perception, by the driver, that the display is of poor quality. 

With great nonuniformities in luminance, however, drivers may not be provided with sufficient luminance and

Contrast to ensure adequate legibility in certain areas of the display.

Icon Design Guidelines ICON LEGIBILITY May 17, 1999 Icon Design Guidelines ICON LEGIBILITY May 17, 1999

3-3

Right-hand page

References

Cross

References

Design

Issues

Discussion

Abbreviated

Handbook Title

(Both Pages)

Abbreviated

Chapter Title

(Both Pages)

Revision Date

(Both Pages) Guideline Title Bar Scale Rating

Introduction

Design

Guideline

References:

1. Mueller, C. G. (1951). Frequency of seeing functions for intensity discrimination at various levels of 

adapting intensity. Journal of General Psychology, 34, 463-474.

2. Boff, K. R., Kaufman, L., & Thomas, J. P. (1986). Handbook of perception and human performance. New 

York: J. Wiley & Sons.

3. Farrell, R. J., & Booth, J. M. (1984). Design handbook for imagery interpretation equipment. Seattle, 

WA: Boeing Aerospace Company.

4. American National Standards Institute. (1988). American national standard for human factors engineering 

of visual display workstations. Santa Monica, CA: Human Factors and Ergonomics Society.

5. MIL-STD-1472D. (1989). Human engineering design criteria for military systems, equipment and 

facilities. Washington, DC: U.S. Government Printing Office.

Discussion: Threshold Luminance Discrimination Data. Although observers in Reference 1 could discriminate 

lights that differed in luminance by as little as 10 percent, these data were obtained when they were trying to 

detect a luminance difference between a background and a target under ideal laboratory conditions (see 

Reference 2 also). Thus, 10 percent represents a threshold luminance discrimination value and is far too 

conservative for IVIS use, in which the issue of concern is the driver's ability to notice luminance differences 

under normal driving or normal viewing conditions.

Tolerance for Luminance Variations. Reference 3 indicates that luminance in cathode ray tubes (CRTs) typically 

varies by as much as 37 percent and is either not noticed or is considered to be acceptable by observers. 

Reference 4 recommends that luminance variations remain below 50 percent. Reference 5 indicates that while 

the preferred limit for luminance variation across optical projection displays is 33 percent, an unacceptable limit 

is 66 percent.

Conclusions. The design objectives provided above reflect a composite of the information provided by 

References 3, 4, and 5. Specifically, if luminance differences up to 37 percent are not always noticed by 

observers and if 33 percent represents a preferred limit, then 33 percent seems to be an acceptable limit for smallarea luminance nonuniformities (i.e., within an individual element or segment). Both 50 percent and 66 percent 

have been suggested as absolute upper limits on luminance nonuniformities.

Design Issues: Causes. Luminance nonuniformities are generally caused by the display itself. In vacuum 

fluorescent displays (VFDs) being viewed directly, for example, these might be caused by poor phosphor 

distribution on the inside of the anodes, or by fluctuations in the power supply output.

Cross References:

Determining the Appropriate Contrast within an Icon, p. 3-4

Measuring Luminance Nonuniformity

Luminance A Luminance B

Within a segment or element of an icon, measure at two

locations using a photometer with a spot size small

enough to fit inside the segment or element.

% Element

Nonuniformity= 

|(Luminance min) - (Luminance max)|

(Luminance max)

(Eq. 1)

Where: Luminance min= the smaller luminance value

Luminance max= the greater luminance value

3-2

Left-hand page Page Numbers

Figure,

Table, or

Graphic

Design Guidelines

Provide no more than 33% Element Nonuniformity (within an individual element or segment).

Based Equally on Expert Judgment

and Experimental Data

Based Primarily on

Experimental Data

Based Primarily on

Expert Judgment

DETERMINING THE APPROPRIATE LUMINANCE UNIFORMITY WITHIN AN ICON

Introduction: Luminance uniformity refers to the consistency of luminance values across an icon. Moderate

nonuniformities in luminance may only lead to the perception, by the driver, that the display is of poor quality. 

With great nonuniformities in luminance, however, drivers may not be provided with sufficient luminance and

Contrast to ensure adequate legibility in certain areas of the display.

Icon Design Guidelines ICON LEGIBILITY May 17, 1999 Icon Design Guidelines ICON LEGIBILITY May 17, 1999

3-3

Right-hand page

References

Cross

References

Design

Issues

Discussion

Abbreviated

Handbook Title

(Both Pages)

Abbreviated

Chapter Title

(Both Pages)

Revision Date

(Both Pages) Guideline Title Bar Scale Rating

Introduction

Design

Guideline

References:

1. Mueller, C. G. (1951). Frequency of seeing functions for intensity discrimination at various levels of 

adapting intensity. Journal of General Psychology, 34, 463-474.

2. Boff, K. R., Kaufman, L., & Thomas, J. P. (1986). Handbook of perception and human performance. New 

York: J. Wiley & Sons.

3. Farrell, R. J., & Booth, J. M. (1984). Design handbook for imagery interpretation equipment. Seattle, 

WA: Boeing Aerospace Company.

4. American National Standards Institute. (1988). American national standard for human factors engineering 

of visual display workstations. Santa Monica, CA: Human Factors and Ergonomics Society.

5. MIL-STD-1472D. (1989). Human engineering design criteria for military systems, equipment and 

facilities. Washington, DC: U.S. Government Printing Office.

Discussion: Threshold Luminance Discrimination Data. Although observers in Reference 1 could discriminate 

lights that differed in luminance by as little as 10 percent, these data were obtained when they were trying to 

detect a luminance difference between a background and a target under ideal laboratory conditions (see 

Reference 2 also). Thus, 10 percent represents a threshold luminance discrimination value and is far too 

conservative for IVIS use, in which the issue of concern is the driver's ability to notice luminance differences 

under normal driving or normal viewing conditions.

Tolerance for Luminance Variations. Reference 3 indicates that luminance in cathode ray tubes (CRTs) typically 

varies by as much as 37 percent and is either not noticed or is considered to be acceptable by observers. 

Reference 4 recommends that luminance variations remain below 50 percent. Reference 5 indicates that while 

the preferred limit for luminance variation across optical projection displays is 33 percent, an unacceptable limit 

is 66 percent.

Conclusions. The design objectives provided above reflect a composite of the information provided by 

References 3, 4, and 5. Specifically, if luminance differences up to 37 percent are not always noticed by 

observers and if 33 percent represents a preferred limit, then 33 percent seems to be an acceptable limit for smallarea luminance nonuniformities (i.e., within an individual element or segment). Both 50 percent and 66 percent 

have been suggested as absolute upper limits on luminance nonuniformities.

Design Issues: Causes. Luminance nonuniformities are generally caused by the display itself. In vacuum 

fluorescent displays (VFDs) being viewed directly, for example, these might be caused by poor phosphor 

distribution on the inside of the anodes, or by fluctuations in the power supply output.

Cross References:

Determining the Appropriate Contrast within an Icon, p. 3-4

Measuring Luminance Nonuniformity

Luminance A Luminance B

Within a segment or element of an icon, measure at two

locations using a photometer with a spot size small

enough to fit inside the segment or element.

% Element

Nonuniformity= 

|(Luminance min) - (Luminance max)|

(Luminance max)

(Eq. 1)

Where: Luminance min= the smaller luminance value

Luminance max= the greater luminance value

Within a segment or element of an icon, measure at two

locations using a photometer with a spot size small

enough to fit inside the segment or element.

% Element

Nonuniformity= 

|(Luminance min) - (Luminance max)|

(Luminance max)

(Eq. 1) % Element

Nonuniformity= 

|(Luminance min) - (Luminance max)|

(Luminance max)

|(Luminance min) - (Luminance max)|

(Luminance max)

(Eq. 1)

Where: Luminance min= the smaller luminance value

Luminance max= the greater luminance value

3-2

Left-hand page Page Numbers

Figure,

Table, or

Graphic

Design Guidelines

Provide no more than 33% Element Nonuniformity (within an individual element or segment).

Based Equally on Expert Judgment

and Experimental Data

Based Primarily on

Experimental Data

Based Primarily on

Expert Judgment

Design Guidelines

Provide no more than 33% Element Nonuniformity (within an individual element or segment).

Based Equally on Expert Judgment

and Experimental Data

Based Primarily on

Experimental Data

Based Primarily on

Expert Judgment
21 

• The topics in the handbook should be arranged in such a way as to permit ready updating 

as new data are provided. 

Developing the preliminary guidelines. The task C preliminary guidelines were subsequently 

developed according to the steps outlined in the workplan described above and distributed to 

both FHWA and the project working group members. The actual table of contents from these 

preliminary guidelines is shown below in figure 9. 

TABLE OF CONTENTS

CHAPTER 1: HOW TO USE THE DESIGN GUIDELINES 

INTRODUCTION 

TWO-PAGE FORMAT 

THE LEFT-HAND PAGE 

Introduction 

Design Guideline 

The Rating System 

Figure, Table, or Graphic 

THE RIGHT-HAND PAGE 

Discussion 

Design Issues 

Cross Reference 

References 

OTHER FEATURES 

CHAPTER 6: THE AUDITORY PRESENTATION OF INVEHICLE INFORMATION

Augmenting Icons with Auditory Information 

Determining the Appropriate Auditory Signal 

Design of Simple Tones 

Design of Earcons 

Design of Auditory Icons 

Design of Speech Messages 

Perceived Urgency of Auditory Signals 

General Design Guidelines for Automatic Speech Recognition 

Systems 

CHAPTER 2: GENERAL ISSUES IN ICON DESIGN 

General Development Process for In-Vehicle Icons 

When to Use Icons 

Ways to Use Icons 

Types of Visual Icons 

Composition of an Icon 

Sequence of Icon Comprehension 

CHAPTER 7: EVALUATING IN-VEHICLE ICONS

Overview of Procedures for Evaluating In-Vehicle Icons 

Production Test 

Appropriateness Ranking Test 

Comprehension/Recognition Test 

Matching Test 

Additional Evaluation Approaches 

CHAPTER 3: ICON LEGIBILITY

Determining the Appropriate Luminance Uniformity within an 

Icon 

Determining the Appropriate Contrast within an Icon 

Determining the Appropriate Size of Icon Components 

Designing Effective Text Labels 

The Effects of Color on Icon Legibility 

CHAPTER 8: ICON COLLECTION

Routing and Navigation Information 

Motorist Services Information 

Augmented Signage Information 

Safety/Warning Information 

Commercial Vehicle Operations (CVO) Information 

General Navigation System Information 

Collision Avoidance Information 

Automated Cruise Control Devices 

CHAPTER 4: ICON RECOGNITION

Level of Realism 

Level of Detail 

Perceptual Principles of Icon Design 

Flash Rate 

Design of Prohibitive Symbols 

CHAPTER 9: TUTORIALS

Analysis of Rank Order Data 

CHAPTER 10: DESIGN TOOL

Sensory Modality Design Tool 

CHAPTER 11: EQUATIONS

CHAPTER 12: GLOSSARY

CHAPTER 13: LIST OF ABBREVIATIONS

CHAPTER 5: ICON INTERPRETATION

Enhancing Icon Interpretation with Text Labels 

Conveying the Effect of Actions with Icons 

Identifying Icons as Part of a Group 

Conveying System Status with Icons 

Enhancing Icon Interpretation with Color 

Conveying Urgency with Icons 

CHAPTER 14: REFERENCES

CHAPTER 15: RELEVANT DOT, SAE, ISO DOCUMENTS

LIST OF ICON WEB SITES

SCOPE AND LIMITATIONS

BACKGROUND

CHAPTER 16: INDEX

Figure 9. Contents from Preliminary Guidelines Handbook 
22 

Developing a working paper that explored information and symbology usage issues. The final 

task C activity was to develop and present an overview of key theoretical, development, 

empirical, or design issues associated with in-vehicle icons. This subtask provided an 

opportunity to consider the work that has been performed during previous project activities and 

to identify areas where additional analysis, empirical study, or guideline development was 

needed. In the task C5 report, ten key issues associated with in-vehicle visual symbols and 

information elements were identified and briefly discussed. These issues were: 

1. The emergence of new and largely untested IVIS technologies. 

2. Lack of empirical data for key icon design topics. 

3. Lack of existing standards. 

4. Selecting a symbolic metaphor for an IVIS message. 

5. Designing by consensus. 

6. Lack of design tools. 

7. Device and/or technology dependencies. 

8. Distributed versus centralized displays. 

9. Amount of information displayed. 

10. Auditory cues for attention-getting and localization. 

TASK D: DEVELOP WORKPLAN FOR FINAL GUIDELINES 

The purpose of task D was to build on the results of tasks B and C to create an updated workplan 

that would identify critical issues associated with icon design and specify empirical evaluations 

for symbol alternatives. Specifically, task D provided an opportunity to consider the work that 

had been performed during previous project activities and to identify specific experiments that 

are needed to address high-priority gaps in the preliminary guidelines developed in task C4. 

The workplans developed during the conduct of task D were directed at key, high-priority human 

factors research issues for icon design and were identified during the six task D activities 

described below in figure 10. 

The contractor made two recommendations to FHWA for the conduct of task E: 

1. Conduct experiments 3 and 6 as described in option C. 

2. Conduct experiment 2 (a low-cost, low-risk experiment) only as time and budget allowed, 

and as directed by FHWA. 
23 

Figure 10. Flow of Task D Activities 

In task D, project working group members were asked to solicit ideas for task E research topics. 

Between the working group members and the project team, 20 candidate research issues were 

identified. These candidate research issues, and their sources, are shown below in table 2. 

Select final research 

issues from larger set 

of candidate issues

Develop and review 

experimental plans 

Identify experimental 

options for Task E 

Review preliminary 

guideline document 

(Task C4)

Review project report titled

"Information Usage

and Symbology Issues"

(Task C5)

Solicit research 

suggestions from the

Project Working Group

IDENTIFY CANDIDATE ISSUES

Select final research 

issues from larger set 

of candidate issues

Develop and review 

experimental plans 

Identify experimental 

options for Task E 

Review preliminary 

guideline document 

(Task C4)

Review project report titled

"Information Usage

and Symbology Issues"

(Task C5)

Solicit research 

suggestions from the

Project Working Group

IDENTIFY CANDIDATE ISSUES

Select final research 

issues from larger set 

of candidate issues

Develop and review 

experimental plans 

Identify experimental 

options for Task E 

Review preliminary 

guideline document 

(Task C4)

Review project report titled

"Information Usage

and Symbology Issues"

(Task C5)

Solicit research 

suggestions from the

Project Working Group

IDENTIFY CANDIDATE ISSUES
24 

Table 2. Candidate Research Issues Identified During the Early Phases of Task D 

CANDIDATE RESEARCH ISSUE SOURCE

• The effects of three different means of attracting driver attention (placement, 

auditory, flashing) on driver safety. 

Preliminary Icon Design 

Guidelines (C4) 

• The effects of flashing and animated icons on driver safety: Should they ever be 

used? 

Preliminary Icon Design 

Guidelines (C4) 

• The evaluation of several different types of collision warning symbols. Preliminary Icon Design 

Guidelines (C4) 

• How long should information be presented to the driver in order to ensure driver 

recognition and comprehension? 

Preliminary Icon Design 

Guidelines (C4) 

• How should information presentation be organized on a display—by priority or 

by subsystem? 

Preliminary Icon Design 

Guidelines (C4) 

• Can earcons be used effectively or are they equivalent to simple tones? Preliminary Icon Design 

Guidelines (C4) 

• Do auditory icons have any applications other than collision warning? Preliminary Icon Design 

Guidelines (C4) 

• How much information should be placed on the display at one time? Information Usage and 

Symbology Issues (C5) 

• Testing of previously untested IVIS technologies, such as collision warning 

systems. 

Information Usage and 

Symbology Issues (C5) 

• Effectiveness of Automatic Speech Recognition (ASR) systems for use in IVIS. Information Usage and 

Symbology Issues (C5) 

• Effectiveness of haptic displays for presenting in-vehicle information to drivers. Information Usage and 

Symbology Issues (C5) 

• Should information be centrally located on a display or distributed across 

displays for different subsystems? 

Information Usage and 

Symbology Issues (C5) 

• How resolution affects icon legibility, especially with respect to Head-Up 

Displays (HUDs). Project Working Group 

• Icons designed for use in non-color systems: Is color necessary for 

interpretation? Project Working Group 

• Complexity of interaction permissible with ASR systems. Project Working Group 

• How to identify earcons as part of a group. Project Working Group 

• Perceived annoyance of auditory signals. Project Working Group 

• When to use digitized versus synthetic speech. Project Working Group 

• Testing of a limited set of promising icons for particular applications (e.g., 

collision warning). Project Working Group 

• Timing of icon display relative to the auditory accompaniment. Project Working Group 
25 

These 20 candidate research issues were reduced to six high-priority research issues through 

application of the following decision criteria to each of the 20 candidate issues: 

• Is the issue directly relevant to the project? 

• Can the experiment be performed within the project’s budget and schedule constraints? 

• Will the experiment yield high-quality human factors design guidelines for in-vehicle 

icons? 

Application of these decision criteria yielded the six high-priority research issues shown below 

in table 3.1

Table 3. Research Issues Developed into Workplans 

RESEARCH ISSUE

1. Evaluating the effects of three different means of diverting attention to in-vehicle information on driver safety. 

2. An evaluation of collision warning symbols. 

3. Auditory signals: Study of perceived urgency and perceived annoyance. 

4. Integration of IVIS icons. 

5. Interaction with an in-vehicle computer: Division of attention between an in-vehicle device and the roadway. 

6. Generic vs. unique icons: Implications for driver understanding of IVIS messages. 

For each of these six research issues, an experimental workplan was developed and then rated 

using a set of explicit decision criteria. Table 4 shows the table used for rating the key issues.2

 

1

 The titles of these issues are somewhat different from those listed in table 2 because some topics were combined 

and slightly modified. 

2

 Raters used a 1-5 scale to indicate how true each of the statements was, with a rating of 5 used to indicate that the 

statement was entirely true and a rating of 1 used to indicate that the statement was entirely not true. 
Table 4. Table for Rating Each of the Key Issues 

 Decision Criteria 

Experiment Number and 

Title 

Relevant data 

currently 

lacking 

Important for 

development of 

current systems 

Important for 

development of 

future systems 

Greatly 

impacts 

driver safety 

Addresses a 

critical 

design need 

Will gene

general d

guideline

in-vehicle 

Experiment 1—Evaluating the effects of three different means of diverting attention to invehicle information on driver safety Experiment 2—An evaluation of collision warning symbols Experiment 3—Auditory signals: Study of perceived urgency and perceived annoyance Experiment 4—Integration of IVIS icons Experiment 5—Interaction with an invehicle computer: Division of attention between an in-vehicle device and the roadway Experiment 6—Generic vs. unique icons: Implications for driver understanding of IVIS messages 

The results from this workplan evaluation process are shown below in table 5. 

26 
Table 5. Results of the Evaluations of the Six Workplans3

 Decision Criteria 

Experiment Number 

and Title 

Relevant data 

currently 

lacking 

Important for 

development of 

current systems 

Important for 

development of 

future systems 

Greatly 

impacts 

driver safety 

Addresses a 

critical 

design need 

Will gene

general d

guideline

in-vehicle 

Experiment 1—Evaluating the effects of three different means of diverting attention to invehicle information on driver safety 

3.00* 3.67 4.00 3.67 4.00 4.00 

Experiment 2—An evaluation of collision warning symbols 

3.67 4.33 4.00 4.67 3.67 1.67 

Experiment 3—Auditory signals: Study of perceived urgency and perceived annoyance 

3.67 3.33 3.33 3.00 3.33 3.00 

Experiment 4—Integration of IVIS icons 4.67 3.00 5.00 3.33 3.33 4.33 Experiment 5—Interaction with an invehicle computer: Division of attention between an in-vehicle device and the roadway 

4.00 4.33 5.00 4.33 3.67 3.00 

Experiment 6—Generic vs. unique icons: Implications for driver understanding of IVIS messages 

4.33 3.33 4.33 3.33 4.33 4.67 

* mean value for all raters (5= true; 3= somewhat true; 1= not true) 

3 Only phase 1 of experiment 3 was rated. 

27 
28 

Based on the results of the evaluations, several experimental options were developed, as shown 

below in table 6. 

Table 6. Summary of Options A, B, C, and D 

OPTIONS

COMBINED 

TECHNICAL 

PRIORITY

PREDICTED STRENGTH 

OF RESULTING 

GUIDELINES

OVERALL RISK

(TECHNICAL,

COST, SCHEDULE) 

Option A:

Experiment 4: Integration of IVIS icons.

Experiment 6: Generic vs. unique icons: 

Implications for driver understanding of 

IVIS messages.

Medium Medium Low-Medium 

Option B:

Experiment 1: Evaluating the effects of 

three different means of diverting attention 

to in-vehicle information on driver safety.

Experiment 2: An evaluation of collision 

warning symbols.

LowMedium Medium Low-Medium 

Option C:

Experiment 3: Auditory signals: Study of 

perceived urgency and perceived 

annoyance.

Experiment 6: Generic vs. unique icons: 

Implications for driver understanding of 

IVIS messages.

Medium Medium Low 

Option D:

Experiment 5: Interaction with an invehicle computer: Division of attention 

between an in-vehicle device and the 

roadway.

Experiment 3: Auditory signals: Study of 

perceived urgency and perceived 

annoyance.

Medium Medium Medium-High 

TASK E: EVALUATE VISUAL SYMBOLS 

The objective of task E was to implement the experimental option selected by the FHWA in task 

D. As recommended in the task D report, FHWA indicated that option C should be implemented 

during the conduct of task E. The two sets of experiments conducted in task E, Experiment 3: 

Urgency and Annoyance of Auditory Alerts, and Experiment 6: General versus Specific Icons: 

Implications for Driver Acceptance of IVIS Messages, are discussed in more detail below. 

Experiment 3: Urgency and Annoyance of Auditory Alerts 

As in-vehicle information systems proliferate, the number of auditory alerts confronting the 

driver may increase dramatically. Auditory alerts alone or in combination with visual displays 

represent a promising approach to displaying information to drivers because they do not require 
29 

drivers to look away from the roadway. Although promising, these systems must communicate 

their messages without distracting or annoying the driver. This study includes a series of five 

experiments focused on how sound parameters affect perceived annoyance, urgency, and 

appropriateness, and how these perceptions affect driving performance. This investigation had 

three specific objectives: 

1. To determine the characteristics of sounds that affect perceived urgency and annoyance. 

2. To determine whether the driving context affects perceived urgency and annoyance. 

3. To determine whether perceived urgency and annoyance affect driving performance. 

In the first four experiments, participants read a short description of a driving scenario and then 

rated and compared a series of sounds according to urgency, annoyance, and appropriateness. 

The short scenarios described the alert as a collision alert, a navigation alert, or an e-mail 

message notification. The fifth experiment used a driving simulator to investigate whether the 

sound parameters affecting urgency and annoyance also affected driving performance. 

The experiments generated substantial support for the following findings: 

• Like urgency, perceived annoyance is systematically related to auditory parameters. 

• Auditory parameters do not uniformly affect perceived urgency and annoyance. This 

makes it possible to tailor sounds to maximize urgency and minimize annoyance. For 

example, to create a alert sound with a high urgency while minimizing annoyance, a high 

density, a slow speed and frequency series should be used. 

• The principles of urgency mapping and annoyance tradeoff provide useful tools to 

maximize the appropriate pairing of sounds to messages and driving context. 

Table 7 summarizes the effect of sound parameters on perceived annoyance and urgency. 
30 

Table 7. The Rank Ordered Means of Experiments 3 and 4 Ratings for Annoyance 

in the E-Mail Scenario 

EXPERIMENT 3 EXPERIMENT 4 

 Onset Offset 

Burst 

Density Mean SD Density Speed Type* Mean SD 

Sound 8 slow slow 3-pulse 51.06 22.57 Sound 6 low fast H/i/ 41.25 17.99 

Sound 7 slow slow 4-pulse 54.19 25.34 Sound 4 low slow FS 43.56 24.12 

Sound 6 slow fast 3-pulse 54.69 24.46 Sound 2 low fast FS 44.88 23.23 

Sound 5 slow fast 4-pulse 57.25 26.91 Sound 8 low slow H/i/ 48.38 24.54 

Sound 3 fast slow 4-pulse 57.44 25.76 Sound 3 high slow FS 58.06 28.31 

Sound 4 fast slow 3-pulse 57.88 23.25 Sound 1 high fast FS 66.56 20.58 

Sound 2 fast fast 3-pulse 61.00 25.97 Sound 7 high slow H/i/ 79.19 13.38 

Sound 1 fast fast 4-pulse 64.88 25.64 Sound 5 high fast H/i/ 80.38 11.95 

Overall Mean 57.30 Overall Mean 57.78 

Standard Deviation 4.26 Standard Deviation 15.93 

* H/i/—high harmonic series; FS—frequency series 

The experiments also identified the following trends that merit further investigation: 

• The driving context affects how sound parameters affect urgency and annoyance. 

• Urgency of alerts for a collision can affect driving performance, suggesting that 

considering urgency in alert designs can enhance driving safety. 

• Urgency may be a relative judgment rather than an absolute and easily recognizable 

characteristic of auditory alerts; measuring urgency in some evaluation contexts thus can 

be problematic. 

• Perceived annoyance is more highly correlated with subjective workload than is urgency; 

annoyance thus may affect driving performance as well as acceptance. 

• The degree to which perceived appropriateness depends on urgency and annoyance 

depends on the driving scenario. The perceived appropriateness of highly critical 

messages depends on perceived urgency, and the appropriateness of less critical messages 

depends on perceived annoyance. 

This research provides some useful design guidance, but several important research issues 

remain. These include identifying the most appropriate sound parameterization, investigating 

how perceptions change with exposure, investigating the efficacy of short sounds, and 

identifying the dependency on scenarios.
31 

Experiment 6: General versus Specific Icons: Implications for Driver Acceptance of IVIS 

Messages 

The experiment 6 study examined issues associated with using general vs. specific icons to 

present in-vehicle information to drivers. The set of experiments addressed the following 

empirical questions: 

• Can general icons effectively convey IVIS information to drivers? 

• Does the effectiveness of general icons vary as a function of the type of information 

conveyed (e.g., ATIS vs. vehicle status vs. collision avoidance)? 

• Is driver age associated with these issues? 

For the purposes of this research, general icons were defined as those that provide the driver 

with information about a broad driving situation or class of conditions without specifying 

detailed information about the situation or conditions. For example, a general icon for the 

message “crash warning” would indicate that a crash is imminent, but would not convey 

information regarding the precise nature of the projected crash (e.g., side, front, or rear crash). 

Specific icons were defined as icons that do provide more detailed information about a driving 

situation or conditions. For example, a family of specific crash warning icons could be used, 

with each icon describing the specific nature of the projected crash (e.g., side, front, or rear 

crash). Figure 11 shows some examples of general and specific icons for key in-vehicle message 

categories. 
32 

 

MESSAGE GENERAL ICONS SPECIFIC ICONS

Trip Navigation: Reduce Speed 

Trip Navigation: Lane Blocked 

Trip Navigation: Road Closed 

Trip Navigation: Emergency Vehicle 

Trip Navigation: Route Guidance 

Collision Avoidance System: Crash Warning 

Vehicle Condition Monitoring: Urgent Mechanical Problem 

Vehicle Condition Monitoring: Vehicle Maintenance Required 

ATIS (Motorist Services): Lodging 

ATIS (Motorist Services): Food 

ATIS (Motorist Services): Gas 

ATIS (Motorist Services): Water Recreation 

Figure 11. Examples of General and Specific Icons for Key In-Vehicle Message Categories 
33 

The study focused on driver comprehension and recognition of icons in a non-driving 

environment. The study had two phases. The objective of Phase 1 was to develop a set of icons 

for Phase 2 testing that met basic comprehension requirements. This was necessary because no 

icons have been standardized or commonly used for many future in-vehicle messages that may 

use icons. Before investigating the study objectives listed above, a set of specific and general 

icons for a range of IVIS functions meeting reasonable comprehension requirements was needed. 

In Phase 1, candidate general and specific icons were generated for a number of IVIS functions 

and driving scenarios. Then comprehension tests were conducted to identify how well these 

candidate icons conveyed their intended meanings. Phase 1 had two parts: Phase 1a consisted of 

initial comprehension testing of candidate general and specific icons; in Phase 1b, the Phase 1a 

icons not meeting basic comprehension levels (50 percent comprehension4

) were redesigned and 

retested. Based on the results of the Phase 1a and 1b comprehension tests, a set of specific and 

general icons was identified for Phase 2 testing. 

The objective of Phase 2 was to assess the degree to which general vs. specific icons matched 

subjects’ understanding of a given driving situation and would be suitable for presentation on an 

IVIS. In Phase 2, all icons were presented within the context of a driving scenario. Phase 2 also 

had two parts: In Phase 2a, subjects were asked to rate how well a given icon described a 

particular driving scenario as well the icon’s perceived effectiveness in helping them understand 

the situation and respond to it with the appropriate driving action. The results from Phase 2a 

were somewhat equivocal. Therefore, in Phase 2b, 69 younger and 78 older subjects were asked 

to select, from among four candidate icons, the most appropriate icon (only one icon could be 

selected) for depicting a given driving situation. In a separate question, they were also asked to 

indicate which of the four icons (they could select up to all four icons) would be acceptable for 

depicting the situation. A sample page from the Phase 2b response booklet is shown in figure 12 

below. 

4

 Fifty percent comprehension levels were chosen simply to ensure that icons tested in Phase 2 were not greatly 

different with respect to comprehensibility. 
34 

Figure 12. A Sample Page from the Phase 2b Response Booklet 

Driving scenario: 

You are driving on the highway. 

You are approaching a section of highway where some unusual activity is going on.

You may need to reduce your speed.

The In-Vehicle Information System in your car presents you with one of the icons shown 

below to inform you of the situation. 

A B C D 

 

1) Please select one icon that most accurately conveys the driving scenario described above 

and circle the letter below which is associated with the selected icon. 

A B C D 

2) Which icon(s) above would be acceptable for this driving scenario? You can select 

more than one icon. 

A B C D 

Driving scenario: 

You are driving on the highway. 

You are approaching a section of highway where some unusual activity is going on.

You may need to reduce your speed.

The In-Vehicle Information System in your car presents you with one of the icons shown 

below to inform you of the situation. 

A B C D 

 

1) Please select one icon that most accurately conveys the driving scenario described above 

and circle the letter below which is associated with the selected icon. 

A B C D 

2) Which icon(s) above would be acceptable for this driving scenario? You can select 

more than one icon. 

A B C D 
35 

Experiment 6 Results 

Effects of Driving Scenario Description Type. The effects of the driving scenario description 

type variable were associated with the strongest and most consistent effects in this Phase 2b 

study. When given a general scenario, subjects consistently chose a general icon as the most 

accurate for the situation. When given a specific scenario, subjects consistently chose a specific 

icon as the most accurate for the situation. Some exceptions were collision avoidance and water 

recreation; for these categories, specific icons were viewed as most accurate regardless of 

scenario description. 

With respect to the acceptability of the icons, the driving scenario description (general or 

specific) had a slightly different effect. For the general scenarios, the general icons were always 

associated with acceptance levels above 80 percent. For the specific scenarios, the specific icons 

were always associated with acceptance levels above 80 percent. However, even with general 

scenarios, the specific icons were associated with at least 80 percent acceptance levels in 15 out 

of 23 message scenarios. With the specific scenarios, the general icons were associated with at 

least 80 percent acceptance levels in 20 out of 23 message scenarios. Overall, the subjects 

reactions to the icons were strongly influenced by their perception of the nature of the driving 

situation associated with an in-vehicle message. 

Effects of Icon Type. As noted above, the effects of icon type (general vs. specific) were 

strongly mediated by the scenario descriptions given to subjects. General icons were selected as 

the most accurate when subjects were presented with a general scenario, and specific icons were 

selected as the most accurate when subjects were presented with a specific scenario. However, 

for two message categories—collision avoidance and water recreation—specific icons were 

selected as the most accurate icons regardless of the scenario description. For the collision 

avoidance icons at least, this suggests that specific icons are desired where safety is an issue, 

perhaps because drivers want to have as much information as is available. 

These general findings however, should be considered in light of the question 2 (acceptability of 

icons) results. While the perceived accuracy of icons varied as a function of the scenario 

described to the subjects, high levels of acceptability were obtained for both the general and 

specific icons, regardless of scenario description. Specifically, the general icons resulted in 80 

percent or higher levels of acceptance in 23 out of 23 messages in the general scenario 

description condition and in 20 out of 23 messages in the specific scenario description condition 

(exceptions were one of the three emergency vehicle messages and both vehicle maintenance 

messages). Therefore, it seems very clear that general icons can meet drivers’ expectations and 

preferences for a broad range of IVIS messages. 

Effects of Icon Message Category. These results have been discussed in the context of 

discussions for the other independent variables, but will be summarized again here. For both the 

collision avoidance and water recreation icon categories, specific icons were viewed as the most 

accurate regardless of scenario description. Unusual results were seen for the “emergency 

vehicle” messages. This is likely due to the generally low comprehension scores associated with 

these icons (especially the generic icon) from experiments 1a and 1b. 
36 

Effects of Distracter Icons. The only instance in which a distracter icon was selected as the 

most accurate was for the “vehicle maintenance required” message. The likely reason for this is 

that the distracter icon selected was a poor choice—it is the same as the generic icon used for 

“urgent mechanical problem.” 

Effects of Gender and Age. In both Phase 2a and Phase 2b, there were some scattered 

significant effects associated with gender and age. However, these effects were small, relatively 

few, and did not fall into any discernible pattern. For the “specific vs. general icon” question, 

age and gender seem to play, at most, a very minor role that should not influence icon design 

recommendations. 

Overall, the task E, experiment 6 research resulted in the following design guidelines for icon 

developers: 

• To minimize driver memory requirements and system complexity, general icons should 

be used as long as they do not negatively impact driver acceptance or driver performance. 

Well-designed general icons will be acceptable to most drivers under most driving 

circumstances. 

• The strongest exception to this seems to be safety-related messages (e.g., collision 

avoidance icons). For safety-related messages, specific icons will provide higher levels 

of driver acceptance than general icons. 

TASK F: DEVELOP FINAL GUIDELINES FOR IN-VEHICLE VISUAL SYMBOLS 

The goal of task F was to develop final guidelines, based on the results and findings from 

previous project tasks. The same general guideline development procedures used in task C were 

to be used to produce the final guidelines. 

In addition, in the fall of 2001, FHWA asked its contractor to develop another product from the 

Icon project. The preliminary guidelines from task C had included an “Icon Collection” of 

approximately 600 candidate icons organized by ITS functional areas, such as routing and 

navigation, motorist services, safety and warning information, collision avoidance, and 

commercial vehicle operations. With respect to this Icon Collection, a key issue of concern 

consistently voiced by the Icon Project Working Group was the lack of evaluative data included 

in the preliminary guidelines for these icons. Information regarding the degree to which these 

individual icons adhere to human factors design principles was not provided in the Icon 

Collection, nor were any suggestions made for improving individual icons. Working group 

members voiced concern that, without some information on the degree to which individual icons 

conform to human factors standards and principles, some users might inadvertently use 

unsuitable icons in their own in-vehicle applications. In response to this concern, FHWA asked 

the contractor to develop an interactive design tool for presenting individual candidate icons in 

the Icon Collection in a manner that also provided evaluative information about the icons. 

Thus, task F included two parallel activities: (1) development of the final hardcopy human 

factors design guidelines, and (2) development of a database software tool. Each is discussed 

below. 
37 

Develop Final Guidelines 

Development of the final design guidelines handbook included the following tasks: 

• Review feedback from FHWA and the project working group. 

• Revise table of contents for the final guidelines. 

• Develop workplan for producing the final guidelines. 

• Make editorial revisions to preliminary guidelines. 

• Update preliminary guidelines with more recent data sources. 

• Develop new guidelines based on more recent data sources. 

• Develop new guidelines based on the task E experimental results. 

• Add new chapter “Relevant USDOT, SAE, and ISO Documents.” 

• Update the Icon Collection. 

• Add an index to the handbook. 

• Update the “Tutorials,” “Design Tool,” “Equations,” “Glossary,” “Abbreviations,” and 

“References” chapters to reflect all revisions to the handbook. 

Figure 9 (shown earlier) illustrates the table of contents from the final design guidelines 

handbook. 

Develop the Icon IDEA Software 

As noted above, the goal of this effort was to develop an interactive design tool for presenting 

individual candidate icons in the Icon Collection in a manner that also provided evaluative 

information about the icons to icon developers. The database software tool (running under 

Microsoft® Access 1997 or 2000) developed in task F is called “Icon Interactive Development 

and Evaluation Assistant” or Icon IDEA. The preliminary version of Icon IDEA is complete; 

development included the following activities. 

Develop Icon Database. Software specifications were developed for the icon database, defining 

the content and format requirements for storing icons to allow users access to the icons based on 

queries for vehicle function and message content. Identifying information associated with each 

icon includes the system function and subfunction, the intended message, the source of the icon, 

and the file name. Microsoft Access has been used for development of both the database and the 

user interface. 

Develop Icon Evaluation Tool. Detailed icon evaluation procedures were developed and 

underwent lengthy internal testing and review. The evaluation focuses on physical, explicit icon 

features that have clear implications for user legibility, recognition, and interpretation. Each 

evaluation factor is well-supported by relevant research data. The tool consists of 28 questions 

that have been coded into Microsoft Access forms with active “buttons” to provide the 
38 

appropriate sequencing of available user actions and input of data into the icon evaluation 

database. The 28 questions are organized into six categories: perceptual principles, level of 

detail, level of realism, use of color, prohibitive icons, and use of text. The tool allows for 

comparisons across raters for a given icon and supports the development of a “consensus” rater 

for developing final evaluation ratings. 

Conduct Icon Evaluations. Using the icon evaluation tool, evaluations of the entire set of icons 

in the Icon Collection were conducted by multiple trained reviewers. Following the completion 

of these independent evaluations, a consensus process resulted in a final evaluation score for 

each icon. 

Conduct Empirical Evaluations of Icon Comprehension. A separate set of comprehension 

evaluations was conducted for 100 of the icons in the Icon Collection. Comprehension tests 

were conducted using 160 paid test subjects who were representative of the driving population 

with respect to factors such as age, gender, and driving experience. Subjects were provided with 

a description of the context in which the icon would be used and then asked to describe the invehicle message that they believe was represented by the icon. 

Develop User Interface. Interface development for Icon IDEA focused primarily upon user 

access to individual icons, evaluation results for the icons, the icon evaluation tool, and general 

design guidelines for icon development and evaluation. Buttons for major IDEA functions, 

supplemented by pull-down menus and dialog windows, provide the primary user interface. 

Users may search for icons by identification number or by icon type (i.e., function, subfunction, 

and category); output includes icons graphics only, graphics plus details, evaluation results, 

design recommendations, and (for a subset of the icons) comprehension study results. 

The Icon IDEA software provides designers with the following basic functions and features: 

• A searchable database of over 400 icons, organized and selectable by specific in-vehicle 

system functions and subfunctions. 

• Access to evaluation scores for each of the icons in the database that reflect critical 

physical features of the icons such as: adherence to perceptual principles, level of detail, 

level of realism, use of color, design of prohibitive icons, and design of text labels. 

• Recommendations for further refining the design of an icon following the consideration 

of the physical feature evaluation. 

• Comprehension ratings from experimental subjects for a subset of the icons. 

• The ability to add new icons into the database, to quickly evaluate critical physical 

features of the icons, and then immediately view the evaluation results and associated 

recommendations for design changes. 

• The ability to add, modify, and delete information about icons, icon evaluations, and icon 

evaluators. 

• The ability to print detailed, full-color reports of all icons and evaluation scores contained 

in the database. 
39 

• Embedded instructions for using Icon IDEA, context-specific help when conducting icon 

evaluations, ScreenTips linked to cursor position on the IDEA screen, and a detailed, online user manual in pdf format 

• Clear and simple design guidelines for developing and evaluating in-vehicle icons in pdf 

format. 

The figure below shows what Icon IDEA looks like when it is launched. 

Figure 13. IDEA Start-Up Screen 

The top bar, with “File” on the left, provides standard Microsoft Windows® options (Page Setup, 

Print, About Icon IDEA, and Exit), as well as the ability to compact the Icon IDEA database. 

Compacting the database is helpful when icons, evaluators, or evaluations have been modified, 

added to the database, or deleted from the database. Using this feature helps to optimize 

runtimes after changes have been made to the database. 

A key feature of Icon IDEA is the ability to search for and to view available icons for a desired 

in-vehicle message. Figure 14 below shows the IDEA screen after such a search. 
40 

Figure 14. Results of the “View Icon Pictures” Function 

Evaluation scores for individual icons can also be obtained. Figure 15 below shows the results 

of searching for certain icon types and then requesting the IDEA software to display evaluation 

scores for one of the icons identified during the search. 
41 

Figure 15. Evaluation Scores for “Physical Features” for the Traffic Congestion Icon 

Figure 15 shows the first of three evaluation reports for the traffic congestion icon. The general 

procedures and specific steps associated with actually conducting a “Physical Features” 

evaluation are discussed in more detail in the IDEA User Manual and will not be reviewed 

here.(5)

As seen in figure 15, the “Physical Features” evaluation addresses six areas of icon design that 

are important for assuring that icons are legible and recognizable. These six design areas are: 

• Perceptual Principles. 

• Level of Detail. 

• Level of Realism. 

• Use of Color. 

• Prohibitive Icons. 

• Text Labels. 

While these six areas do not capture all aspects of icon design that are important for legibility 

and recognizability, they do reflect icon design guidelines that: (1) are consistently identified as 

central to good icon design; (2) are well supported by numerous empirical studies contained in 
42 

the icon design literature; and (3) can be assessed in a reasonable and consistent fashion with a 

tool such as Icon IDEA. 

Figure 15 shows the degree to which the traffic congestion icon reflects good icon design 

practices within each of the six evaluation areas. As seen in the figure, the “Percent 

Compliance” for the “Perceptual Principles” design guidelines was 90 percent for this icon. The 

“Level of Detail,” “Level of Realism,” and “Use of Color” evaluation areas were all in 100 

percent compliance with their associated design guidelines. Due to the nature of the traffic 

congestion icon, both the “Prohibition Icons” and “Text Labels” evaluation areas were not 

applicable (N/A). 

Figure 16 below shows the second of three evaluation reports for the traffic congestion icon. 

Figure 16. Comprehension Scores for the Traffic Congestion Icon 

The comprehension scores shown in figure 16 reflect an empirical study involving 160 test 

subjects and 100 (from the more than 400 total) icons in the IDEA database. 

The column on the left hand side of the icon scores report in figure 16 shows the eight possible 

categories that could be used to score the subjects’ responses in the comprehension testing. The 

column on the right shows the percentage of subject responses falling into each of these eight 

categories. Acceptable levels of comprehension are usually considered to be associated with the 
43 

first two categories of this 8-point scale (i.e., either “the response matches the intended meaning 

of the icon exactly” or “the response captures all key informational elements of the intended 

meaning of the icon, but is missing one or more minor elements”). 

Therefore, the total percent comprehension score for the traffic congestion icon represents the 

sum of the subject responses falling into categories 1 and 2 (53.2 percent plus 40.3 percent 

equals 93.5 percent). This is a very high comprehension rate: Acceptable comprehension rates 

for icons and symbols are usually considered to be 66 percent or, in certain cases, 85 percent. It 

should be noted that, at this time, the Icon IDEA software does not support adding in new 

comprehension scores for new or existing icons, or for modifying the existing comprehension 

scores. 

Figure 17. Design Recommendations for the Traffic Congestion Icon Reflecting the 

“Physical Features” Evaluation Results 

Figure 17 shows the third of three evaluation reports for the traffic congestion icon; this report 

provides recommended design changes for the icon. The design recommendations for all icons 

in the IDEA database are based on possible design problems identified during the “Physical 

Features” evaluations. These recommendations directly reflect less-than-100 percent compliance 

with any of the design guidelines associated with the “Perceptual Principles,” “Level of Detail,” 

“Level of Realism,” “Use of Color,” “Prohibitive Icons,” or “Text Labels” evaluation areas. 

Therefore, any time a physical feature score for an icon is less than 100 percent, design 
44 

recommendations will be provided for the icon. For the traffic congestion icon, only one design 

recommendation is provided. Recall (from figure 15), that the percent compliance for the 

“Perceptual Principles” evaluation area was 90 percent. In figure 17, we see that the design 

recommendation provided—“a reduction in symbol complexity would improve recognition”—is 

associated with the “Perceptual Principles” evaluation area and a design guideline for icon 

simplicity. 
45 

CHAPTER 3: CONCLUSIONS 

As noted above, the overall goal of the project has been to provide the designers of in-vehicle 

technologies with a set of design guidelines for in-vehicle display icons and other information 

elements. The final design guidelines provided in task F have clearly achieved this goal. These 

clear, relevant, and easy-to-use guidelines provide up-to-date information on a number of topics 

critical to icon development and evaluation. 

Much of the impetus behind the initial conceptualization of this project can be summed up by 

going back to two of the conclusions from the final task A report: 

• “The lack of guidelines and standards for icons has resulted in design by consensus, a 

lack of scientific rigor in icon development, and multiple icons for the same messages.” 

• “Existing literature and standards provide little guidance for the design of new icons for 

IVIS devices.” 

In short, the transportation system design community—and, indeed, the larger 

electronics/computer industry—has not had the benefit of a single information source that 

provided clear, relevant, and useful guidance for icon design. The final task F guidelines 

produced in this project therefore fill a critical gap in the transportation human factors literature. 

In addition, the Icon IDEA software tool developed in this project has provided a real-time icon 

development and evaluation tool that, to date, is receiving consistently positive reviews from the 

project’s working group members. This tool is entirely functional and ready to use, and should 

prove an invaluable aid and resource for icon design. 

Moreover, the technical reports, conference papers, and conference presentations developed 

during this project provide a permanent record on a number of substantive issues related to icon 

design, yet perhaps not incorporated into either the final design guidelines or the IDEA software 

tool. Appendix B summarizes these products. 

47 

APPENDIX A: PROJECT WORKING GROUP1

 

1

 List includes both current and past working group members. 

Linda Angell, Ph.D. 

General Motors Corporation 

Mike Campbell 

National Weather Service 

Cher Carney 

Battelle Human Factors Transportation Center 

Peter Chin 

Microsoft 

Mark Cummings-Hill 

Delphi Delco Electronics Systems 

David G. Curry, Ph.D. 

Packer Engineering, Inc. 

Stuart DeSpain 

Microsoft 

James P. Foley, Ph.D. 

Mitretek Systems, Inc. 

Thomas M. Granda, Ph.D. (FHWA COTR) 

Federal Highway Administration 

Barry S. Grant 

Ford Motor Company 

Ronald B. Hoffman, Ph.D. (SAIC) 

Federal Highway Administration 

David Hoffmeister 

Ford Motor Company 

Maureen L. Hunter 

Avia Technology 

Steven K. Jahns, Ph.D. 

PACCAR Technical Center 

Barry H. Kantowitz, Ph.D. 

University of Michigan Transportation 

Research Institute 

Rick Karbowski 

Ford Motor Company 

Raymond J. Kiefer 

General Motors Corporation 

Chris Kirn 

DaimlerChrysler Research and Technology 

James A. Kleiss, Ph.D. 

Johnson Controls, Inc. 

Ken Kobetsky 

American Association of State Highway and 

Transportation Officials 

John D. Lee, Ph.D. 

University of Iowa 

Eddy Llaneras, Ph.D. 

Westat, Inc. 

Marvin McCallum, Ph.D. (Project Task Leader) 

Battelle Human Factors Transportation Center 

Christopher Monk (SAIC) 

OHCR, National Highway Traffic Safety 

Administration 

Mark Ohashi 

Toyota Technical Center, USA 

Colleen Page 

Microsoft 
48 

Joel Richman (Project Task Leader) 

Battelle Human Factors Transportation Center 

Gary L. Rupp, Ph.D. 

Ford Motor Company 

Tina Brunetti Sayer, Ph.D. 

Visteon Corporation 

Colleen Serafin 

Johnson Controls, Inc. 

Valerie K. Sims, Ph.D. 

University of Central Florida 

Marc Todd 

Microsoft 

Ben Truelove 

Microsoft 

Blaine Tsugawa 

Office of the Federal Coordinator for 

Meteorology, National Oceanic Atmospheric 

Administration 

Jonathan Upchurch, Ph.D., P.E. 

University of Massachusetts - Amherst 

Dave Wheatley 

Motorola Laboratories 

Peter Wolff 

DaimlerChrysler Research and Technology 

Steven Wreggit, Ph.D. 

DaimlerChrysler Research and Technology 
49 

APPENDIX B: TECHNICAL REPORTS, PUBLICATIONS, AND PRESENTATIONS 

Technical Reports 

Campbell, J. L. and Carney, C. (1998). In-vehicle display icons and other information elements. 

Task C: Workplan for developing preliminary design guidelines for in-vehicle symbols 

(Draft Report). Seattle, WA: Battelle Human Factors Transportation Center. 

Campbell, J. L., and Carney, C. (1999). In-vehicle display icons and other information 

elements. Task C5: Information usages and symbology issues (Final Report). Seattle, 

WA: Battelle Human Factors Transportation Center. 

Campbell, J. L., Carney, C., and Lee, J. D. (1999). In-vehicle display icons and other 

information elements. Task C4: Preliminary in-vehicle symbols guidelines (Final 

Report). Seattle, WA: Battelle Human Factors Transportation Center. 

Campbell, J. L., Carney, C., Simsek, O., Bittner, A. C. Jr., and Lee, J. D. (2000). In-vehicle 

display icons and other information elements. Task D: Develop workplan for final 

guidelines (Final Report). Seattle, WA: Battelle Human Factors Transportation Center. 

Campbell, J. L., Richman, J. B., Carney, C., and Lee, J. D. (2002). In-vehicle display icons and 

other information elements. Task F: Final in-vehicle symbols guidelines (Final Report). 

Seattle, WA: Battelle Human Factors Transportation Center. 

Campbell, J. L., Richman, J. B., Nakata, A., Simsek, O., and Schmidt, K. (2002). In-vehicle 

display icons and other information elements. Task E, Experiment 6. General versus 

specific icons: Implications for driver acceptance of IVIS messages (Final Report). 

Seattle, WA: Battelle Human Factors Transportation Center. 

Campbell, J. L., Slavich, A., and McCallum, M. C. (2002). In-vehicle display icons and other 

information elements. User manual for Icon IDEA (Icon Interactive Development and 

Evaluation Assistant) Prototype Version 1. Seattle, WA: Battelle Human Factors 

Transportation Center. 

Carney, C., Campbell, J. L., and Mitchell, E. A. (1998). In-vehicle display icons and other 

information elements. Task A: Literature review (Final Report). Washington, DC: 

Federal Highway Administration. 

Lee, J. D., Carney, C., Casey, S. M., and Campbell, J. L. (1998). In-vehicle display icons and 

other information elements. Task B: Conduct preliminary assessment of visual symbols

(Final Report). Seattle, WA: Battelle Seattle Research Center. 

Lee, J. D., Marshall, D., Austria, P. A., Wiese, E., and Williams, E. (2002). In-vehicle display 

icons and other information elements. Task E, Experiment 3. Urgency and annoyance of 

auditory alerts (Final Report). Iowa City, IA: University of Iowa. 
50 

Publications 

Campbell, J. L., Carney, C., and Lee. J. D. (1999). “Icons.” In The Industrial and Occupational 

Ergonomics:Users Encyclopedia (CD-ROM). Encyclopedia of Ergonomics. 

Campbell, J. L., Carney, C., Monk, C., Granda, T., and Lee, J. D. (2000). Design guidelines for 

in-vehicle icons (CD-ROM). ITS AMERICA 10th Annual Meeting. Washington, DC: 

ITS America. 

Campbell, J. L., McCallum, M. C., and Richman, J. B. (2002). Development of Icon IDEA: 

Icon Interactive Development and Evaluation Assistant (CD-ROM). ITS AMERICA,11th

Annual Meeting. Washington, DC: ITS America. 

Marshall, D., Lee, J. D., and Austria, P. A. (2001). Annoyance and urgency of auditory alerts 

for in-vehicle information systems (CD-ROM). Proceedings of the 45th Annual Meeting 

of the Human Factors and Ergonomics Society, pp. 1627-1631. Minneapolis/St. Paul, 

MN. 

Nakata, A., Campbell, J. L., and Richman, J. B. (2002). Driver acceptance of general vs. 

specific icons for in-vehicle information. Proceedings of the 46th Annual Meeting of the 

Human Factors and Ergonomics Society. Baltimore, MD. 

Richman, J. B., Campbell, J. L., and McCallum, M. C. (2002). Effective IVIS comprehension 

research: Context and response scaling methods. Proceedings of the 46th Annual Meeting 

of the Human Factors and Ergonomics Society. Baltimore, MD. 

Wiese, E., and Lee, J. D. (2001). Effects of multiple auditory alerts for in-vehicle information 

systems on driver attitudes and performance (CD-ROM). Proceedings of the 45th Annual 

Meeting of the Human Factors and Ergonomics Society, pp.1632-1636. Minneapolis/St. 

Paul, MN. 

Presentations 

Campbell, J. L. (2000, January). In-vehicle icons: Making sure that what you get is what you 

see. Presented at the annual meeting of the Transportation Research Board, Washington, 

DC. 
51 

REFERENCES 

1. Campbell, J.L. (1995). Development of human factors design guidelines: Science and art. 

In A.C. Bittner, Jr., and P.C. Champney (Eds.), Advances in industrial ergonomics and 

safety VII (pp. 105-112). London: Taylor & Francis. 

2. Campbell, J.L. (1996). The development of human factors design guidelines. International 

Journal of Industrial Ergonomics, 18(5-6), 363-371. 

3. Campbell, J.L., Bittner, A.C., Jr., Lloyd, M., Mitchell, E., and Everson, J. H. (1997). Drivervehicle interface (DVI) design guidelines for the Intersection Collision Avoidance (ICA) 

system (Final Report). Seattle, WA: Battelle Human Factors Transportation Center. 

4. Campbell, J.L., Carney, C., and Kantowitz, B.H. (1998). Human factors design guidelines 

for advanced traveler information systems (ATIS) and commercial vehicle operations 

(CVO), (FHWA-RD-98-057). Washington, DC: Federal Highway Administration. 

5. Campbell, J.L., Slavich, A., and McCallum, M.C. (2002). In-vehicle display icons and other 

information elements. User manual for Icon IDEA (Icon Interactive Development and 

Evaluation Assistant) Prototype Version 1. Seattle, WA: Battelle Human Factors 

Transportation Center.