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Volpe Center Highlights - November/December 2005

Focus

Director's Notes | Focus | Safety | Mobility | Environmental Stewardship
Security | Organizational Excellence | Awards | Published and Presented

Human factors researchers at the Volpe Center analyze the relationship between human behavior and transportation safety and productivity, applying a systems approach. Developments in knowledge and procedures are successfully transferred across modes to resolve a range of transportation problems.

Factoring in Human Behavior

Human error is thought to contribute to 60 to 80 percent of all transportation accidents. One of the greatest challenges in transportation, therefore, is designing technology and procedures that reduce the probability of such error by taking human behavior into account. Meeting this challenge requires a comprehensive approach to determine where an "error" may occur: in the cockpit, in the control room, on the drawing board, or in the boardroom.

The Volpe Center's Human Factors Division applies knowledge of human capabilities and limitations to the design of technological and organizational systems. Human factors researchers apply analytical and technical skills to address the complex environments in which crews, dispatchers, traffic controllers, and maintenance workers perform their jobs, as well as challenges faced by the traveling public. This comprehensive perspective provides a framework for investigation on various scales, from the design of handheld devices to the impacts of sign color and placement, to an organization's safety culture. Addressing emerging issues such as fatigue and distraction, as well as ongoing trouble spots such as airport runways and highway-rail grade crossings, the Division demonstrates the Volpe Center's systems approach to problem solving.

Operator Fatigue and Alertness

Fatigue may produce mental decrements that impact operator vigilance, judgment, and decision making thereby increasing the risk of human error and, potentially, injuries and fatalities. Although fatigue is increasingly recognized as a critical safety factor, the incidence of fatigue is underestimated in virtually every transportation mode because it is difficult to measure and quantify. The Volpe Center's Fatigue Monitoring and Countermeasures Research team—co-led by Dr. Heidi Howarth and Dr. Stephen Popkin, Chief of the Human Factors Division—explores issues of measuring and managing fatigue and alertness issues in all modes.

Drowsy Driver Warning System

Drowsy drivers are considered by some to be responsible for well over 100,000 automobile crashes each year. As part of DOT's Intelligent Vehicle Initiative, the Volpe Center is evaluating a commercially available drowsy driver warning system for the National Highway Traffic Safety Administration and the Federal Motor Carrier Safety Administration.

The device monitors eye closure and alerts a vehicle operator when its predicted driver drowsiness exceeds a threshold. This Volpe team, led by Dr. Bruce Wilson, is evaluating device performance, safety benefits, driver acceptance, and deployment prospects.

DOT's Operator Fatigue Management Program

Fatigue management requires changes in organizational culture and operator behavior. Accordingly, the Operator Fatigue Management (OFM) Program brings together government, labor, and industry-developed tools to aid in understanding and managing fatigue in a nonprescriptive fashion. Dr. Stephen Popkin co-chairs this multimodal DOT initiative, whose recent products include tools such as software to help schedulers design ergonomic work schedules that promote on-duty alertness, fatigue model validation procedures, and the Fatigue Management Reference Guide. For more on the OFM Program, see http://scitech.dot.gov/research/human/ofm.html.

Driver Distraction

NHTSA estimates that driver distraction and inattention contribute to 20 to 30 percent of police-reported vehicular crashes—about 1.5 million crashes a year, and the level of driver distraction is expected to increase. As more complex controls, displays, communications devices, and entertainment systems appear in cars, human factors research is vital to understanding not only how and why drivers become distracted, but what countermeasures work best in the increasingly dynamic driving environment. NHTSA's Crash Avoidance Research Division is exploring in-vehicle technologies that help ensure that the demands imposed on drivers' attention do not overwhelm their capability to process and respond to information. The Volpe Center provides program management and technical support to a high-priority NHTSA project using a test vehicle called SAVE-IT (Safety Vehicle Using Adaptive Interface Technology). The goal of SAVE-IT is the development of a central monitoring system that integrates data from in-vehicle technologies and controls the flow of information to the driver through an adaptive driver-vehicle interface. Dr. Mary Stearns leads the Volpe Center SAVE-IT team. For more on SAVE-IT, visit www.volpe.dot.gov/opsad/saveit/index.html.

Information Communication and Display

Several Volpe Center projects address human factors considerations in the design and evaluation of communications and display technologies in aviation and rail operations.

Electronic Flight Bags. Instead of traditional flight bags loaded with paper documents such as checklists, operating manuals, and navigation publications, many flight crews are bringing aboard electronic flight bags (EFBs) in the form of handheld, laptop, or tablet computers, as shown above. In support of FAA, the Volpe Center has performed significant research related to EFBs and has developed guidelines for their design and evaluation. Details on the Center's EFB work are available at www.volpe.dot.gov/opsad/efb. (Photo courtesy of Teledyne Controls)

Flight-Deck Displays

Any new electronic display introduced into an operator's environment could have negative consequences if it is not implemented appropriately. On the flight deck, the consequences are particularly serious. An increasing number of electronic displays, ranging from small handheld displays for general aviation to installed displays for commercial air transport, show navigation information such as symbols representing navigational aids.

The wide range of technologies and functions makes it difficult to design symbols that are easily recognizable across platforms. For the Federal Aviation Administration, Dr. Michelle Yeh and Dr. Divya Chandra developed a method to design and evaluate symbology that takes into account the different media (e.g., paper vs. electronic) and platforms on which they will be displayed. This report is available at www.volpe.dot.gov/opsad/pubs.html.

The Center is also investigating human factors issues related to head-up displays (HUDs). An HUD projects imagery on a transparent screen that overlaps the pilot's forward field of view so a pilot can quickly shift attention between flight information shown on the display and the outside view. This allows pilots of civil air transport to conduct manual approaches, landings, and takeoffs in especially poor visibility. However, the displayed imagery can interfere with the outside view, creating visual "clutter." The Volpe Center's Dr. Michael Zuschlag is conducting research on clutter effects in order to provide FAA with certification guidelines for HUDs.

Intelligent Railroad Systems

For the Federal Railroad Administration, Dr. Jordan Multer and Dr. Thomas Sheridan led two studies related to communications equipment. The first involved the design of a wireless handheld computer; the study gauged user acceptance and identified human factors design issues for workers and dispatchers as the design evolved. Another study focused on safety, efficiency, and productivity issues associated with the introduction of a visually based (graphical and textual) data link interface for dispatchers. The reports are available at www.volpe.dot.gov/opsad/pubs.html.

Voice Communication Among Transportation Workers

Building on significant Volpe Center research into voice communication between pilots and air traffic controllers, new work at the Center is analyzing voice communication among train dispatchers, crews, and maintenance workers. In addition to supporting the design of communications systems, these studies can shed light on factors that contribute to operational errors.

Visual and Acoustic Warnings at Grade Crossings

The Volpe Center investigated the effectiveness of several train-mounted reflector patterns to improve motorist recognition of a train. Four patterns were evaluated in two experiments, using a driving simulator.

A significant portion of collisions at grade crossings can be tied to human behavior. Volpe Center human factors experts help designers develop systems with the right balance of passive (e.g., signs and markings) and active (e.g., technology) warnings. The research discussed below also contributed to federal rules regarding visual and acoustic methods to improve motorist perception of trains at grade crossings.

The exterior of the typical freight car is painted in dark colors and frequently dirty; it absorbs the light from motor vehicle headlights, making it hard to see at night. Retroreflective materials reflect light from motor vehicle headlights back to the motorist. Volpe Center experiments on retroreflective materials have considered human factors issues such as the complexity of the visual environment faced by motorists and the relative visibility of various patterns of materials. This work, led by Dr. Jordan Multer, contributed to the development of a federal rule, effective March 2005, requiring retroreflective materials on locomotives and freight cars.

For more than a decade, researchers at the Volpe Center have been investigating how to improve motorist perception of train location with optimal acoustic warning systems. The Center's recent work, led by Ms. Gina Melnik, built upon earlier train horn research conducted in the 1990s to optimize the sound quality and effectiveness of horns for use on locomotives or in wayside horn systems. In addition to meeting the primary goal of improved safety at grade crossings, this sound quality research also focuses on minimizing noise pollution in surrounding communities. The Volpe team has contributed significantly to the development and issuance of the Final Rule for Use of Locomotive Horns at Highway-Rail Crossings.

Emergency Rail Passenger Evacuation

During an emergency, the safe and efficient evacuation of rail passengers may depend on train designs that take into account human behavior under stressful conditions. The Center's Human Factors Division is supporting the Railroad Systems Division in investigating issues relating to passenger rail car evacuations during various emergency scenarios. Specific areas being explored include the number and configuration of emergency exits as well as their markings and instructions, and emergency lighting. As part of this research, Ms. Stephanie Markos of the Railroad Safety Division and Mr. John Pollard of the Human Factors Division recently conducted a series of commuter rail car passenger egress tests to obtain human factors data related to the length of time necessary for passengers to exit under both normal and emergency lighting conditions. This work is part of ongoing emergency preparedness research performed for FRA.

Runway Safety

When an aircraft or ground vehicle inadvertently taxis or drives onto an active runway without authorization, this incursion can present a serious hazard to aircraft that are taking off or landing. Runway incursions have been blamed in several major accidents; accordingly, FAA and the National Transportation Safety Board both list the prevention of runway incursions among their highest priorities. The Volpe Center is engaged in several FAA technical efforts to reduce runway incursions. In addition to lending human factors expertise to technical projects, members of the Human Factors Division have created educational materials for pilots and controllers.

A Volpe-developed booklet, Runway Safety: It's Everybody's Business, first published in 2002 and now in its third printing, presents detailed examples of scenarios that lead to incursions. Aimed at clarifying the roles and responsibilities of pilots and controllers, it addresses problems from both perspectives and provides tips on how pilots and controllers can improve their performance and help each other work together more effectively. The booklet is available at www.faa.gov/runwaysafety/handbook.cfm.

Based on this booklet, the same Volpe Center team, led by Dr. Kim Cardosi and Dr. Daniel Hannon, developed a prototype tool for training tower controllers. This interactive CD contains "learn-by-doing" modules that cover topics such as:

• Limitations of short-term memory and the effects of distractions
• Effects of expectation and selective attention on information processing
• Common errors in controller-pilot communications
• Teamwork strategies for mitigating the effects of individual errors
• Avoiding and managing the effects of fatigue.

New Approaches to Improving Safety Culture

The Volpe Center is engaged in the implementation of two approaches to gathering and analyzing safety-related data that hold promise for preventing rail accidents and reducing injuries: close-call analysis and behavior-based safety.

Accidents are often preceded by "close calls," which can provide warnings about unsafe conditions. Studying close calls can help identify safety hazards and develop solutions that prevent accidents. But implementing a reporting system that encourages employees to disclose safety-critical information requires a sense of trust as well as a voluntary and confidential reporting system. Dr. Jordan Multer leads a Volpe Center team that manages an FRA program designed to demonstrate the effectiveness of a Confidential Close Call Reporting System for the railroad industry.

Behavior-based safety (BBS) is a proactive process that identifies and observes safety-critical behaviors and provides positive peer-to-peer feedback. It can also be used to identify and mitigate organizational barriers to safe behavior, such as work environment, policies, and procedures. A variety of BBS approaches have been used to reduce at-risk behaviors and injury rates in other industries. Dr. Joyce Ranney leads the Volpe Center team that supports FRA in assessing BBS for use in railroading. The goal of this work is twofold: to evaluate individual demonstration projects that apply specific BBS methodologies, and to investigate broader issues, such as implementation, cost, and feasibility, that could influence industry-wide BBS application.

The Future of Transportation

Emerging technologies will continue to alter the transportation enterprise, increasing the amount of information available to operators, and changing the knowledge, skill, and abilities required of them. Advances in the understanding of individual and organizational behavior will help shape the transportation community's response to these challenges. The Volpe Center's Human Factors Division—with an interdisciplinary work style that enables the cross-fertilization of ideas—will help to ensure that safety risks are fully addressed, and that advances in one area don't compromise safety or efficiency in another.

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