U.S. Department of Transportation
Federal Highway Administration
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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
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Publication Number: FHWA-RD-95-197
Date: December 1996
Development of Human Factors Guidelines for Advanced Traveler Information Systems and Commercial Vehicle Operations: Comparable Systems Analysis
Advanced Traveler Information Systems (ATIS) and Commercial Vehicle Operations (CVO) systems are important subsets of the Intelligent Transportation System (ITS) initiative of the U.S. Department of Transportation. ITS is intended to increase productivity and safety in future transportation systems through the application of advanced technology. The present study was one portion of a large-scale FHWA effort to develop human factors guidelines for ATIS and CVO systems. The objectives of this comparable systems analysis were to identify seven systems representative of ATIS/CVO features and functions, analyze those systems with respect to human factors issues, establish lessons learned in the design and evaluation of the systems, and derive human factors guidelines for future ATIS/CVO systems. Due to several constraints, this study targeted accessible systems in the United States and, therefore, the systems identified and analyzed were not representative of all existing ATIS systems.
A large list of potential candidate systems was compiled by combing the literature and by communicating with members of the ITS community. Seven systems were selected for the comparable systems analysis. The criteria used to select the systems included the following: relevance to ATIS/CVO concepts and features; similarity to specific ATIS subsystems (i.e., IRANS, IMSIS, ISIS, IVSAWS); advanced technology with interactive displays; dynamics of information flow; system complexity; implementation level; user population training level; user time-sharing requirements; and accessibility of the system for analysis. The seven systems selected for analysis were:
TravTek - This was an existing in-vehicle route guidance and navigation system that was undergoing the final phases of testing in Orlando, Florida.
UMTRI - An instrumented vehicle being used to conduct research on in-vehicle displays for navigational and routing purposes. The several years of research experience with navigation displays were expected to produce insightful lessons learned.
Navmate - This route guidance and navigation system was being tested by the manufacturer in rental cars in the San Jose, California area.
OmniTRACS - This system was a CVO-specific system and featured on-board two-way communication through the use of an in-vehicle unit currently installed in more than 50,000 trucks. The system was designed to facilitate the dispatcher-driver communication link with respect to shipment status and delivery, but also allowed route guidance and navigation information to be transmitted and received.
TravelPilot - This in-vehicle display system was installed in Seattle Fire Department trucks to provide two-way communication with a dispatch center. Real-time vehicle location and destination were the primary functions of the system.
Crew Station Research and Development Facility - This Army flight simulator for crew systems research includes several advanced technology features relevant to ATIS/CVO, such as a touchscreen digital map, out-the-window symbology (equivalent to a head-up display), voice interaction, and dynamic information flow with multi-tasking.
Army Helicopter Mission Replanning System - This system features a digital map that incorporated the output of a cognitive decision-aiding system to assist pilots in selecting alternate mission plans and routes.
To reveal as many lessons learned as possible, several methods of analyses were used. A thorough analysis of existing documentation (e.g., technical manuals, schematics, specifications, training videos/manuals, and user manuals) was performed for each system. Many of the lessons learned were derived from human factors heuristic evaluations in which human factors experts analyzed the systems while engaging in direct interaction with the equipment. This method was not possible for all the systems due to limited accessibility. When possible, volunteer target participants were asked to use the system following a structured set of tasks using a verbal protocol analysis wherein the participants were asked to describe their impressions, thoughts, and opinions of the system while they performed the specified tasks. Videotape records of this procedure were collected when possible. Interviews with design team members were intended to collect information about the rationale and criteria for the human factors design of the system. These interviews attempted to discover whether human factors guidelines were used in the design and, if so, were they helpful.
From the thorough data collection efforts, 177 lessons learned were identified. A chapter is dedicated to each system and the lessons derived from each system are listed at the end of each chapter. All the lessons learned were coded such that each could be linked back to the original system. The lessons learned were then grouped and categorized in a process aimed at developing human factors guidelines pertinent to each group. From this activity, 66 preliminary human factors guidelines for ATIS/CVO systems were generated and listed in a separate chapter. The preliminary guidelines produced from this comparable system analysis addressed a wide range of human factors issues, including some that are specific to ATIS/CVO systems, and some relevant to the use of human factors handbooks. Each guideline is accompanied by a list of system-specific codes of the lessons learned that contributed to that guideline. To facilitate use by ATIS and CVO designers and evaluation groups, the guidelines are grouped into 13 categories. The human factors categories and an example of a usability principle for that category identified in the survey of comparable systems are: In-Vehicle Display Design; Controls; User-System Interface; Driver Attention/World/Safety; Driver Information Requirements; Route Guidance/Planning/Navigation; Map Databases; Vehicle Location Accuracy; Driver Acceptance; Communication Between Driver and Dispatch/Help Center; Training Issues/Requirements; Handbooks and Guidelines; and Design Approaches.
The guidelines developed in this report should be considered preliminary. They are based on observation, expert judgment, user opinion, and other subjective analyses. However, the strength of the method used is that these preliminary guidelines were derived from actual ATIS/CVO systems. There is little doubt that preliminary guidelines, even when based on subjective analysis, are more likely to be applicable and relevant when they are derived from existing systems than from different application areas. Empirical validation of these preliminary guidelines is essential before considering them as actual guidelines for the human factors design of ATIS/CVO systems.