VTechWorks Repository :: Browsing by Author "Dingus, Thomas A."

Browsing by Author "Dingus, Thomas A."

Now showing 1 - 20 of 74

Analytic Assessment of Collision Avoidance Systems and Driver Dynamic Performance in Rear-End Crashes and Near-Crashes
McLaughlin, Shane Brendan (Virginia Tech, 2007-10-30)
Collision avoidance systems (CASs) are being developed and fielded to reduce the number and severity of rear-end crashes. Kinematic algorithms within CASs evaluate sensor input and apply assumptions describing human-response timing and deceleration to determine when an alert should be presented. This dissertation presents an analytic assessment of dynamic function and performance CASs and associated driver performance for preventing automotive rear-end crashes. A method for using naturalistic data in the evaluation of CAS algorithms is described and applied to three algorithms. Time-series parametric data collected during 13 rear-end crashes and 70 near-crashes are input into models of collision avoidance algorithms to determine when the alerts would have occurred. Algorithm performance is measured by estimating how much of the driving population would be able to respond in the time available between when an alert would occur and when braking was needed. A sensitivity analysis was performed to consider the effect of alternative inputs into the assessment method. The algorithms were found to warn in sufficient time to permit 50–70% of the population to avoid collision in similar scenarios. However, the accuracy of this estimate was limited because the tested algorithms were found to alert too frequently to be feasible. The response of the assessment method was most sensitive to differences in assumed response-time distributions and assumed driver braking levels. Low-speed crashes were not addressed by two of the algorithms. Analysis of the events revealed that the necessary avoidance deceleration based on kinematics was generally less than 2 s in duration. At the time of driver response, the time remaining to avoid collision using a 0.5g average deceleration ranged from â 1.1 s to 2.1 s. In 10 of 13 crashes, no driver response deceleration was present. Mean deceleration for the 70 near-crashes was 0.37g and maximum was 0.72g. A set of the events was developed to measure driver response time. The mean driver response time was 0.7 s to begin braking and 1.1 s to reach maximum deceleration. Implications for collision countermeasures are considered, response-time results are compared to previous distributions and future work is discussed.
Assessing Negative Side Effects in Virtual Environments
McGee, Michael K. (Virginia Tech, 1998-01-26)
Virtual environment (VE) systems have been touted as exciting new technologies with many varied applications. Today VEs are used in telerobotics, training, simulation, medicine, architecture, and entertainment. The future use of VEs seems limited only by the creativity of its designers. However, as with any developing technology, some difficulties need to be overcome. Certain users of VEs experience negative side effects from being immersed into the graphically rendered virtual worlds. Some side effects that have been observed include: disorientation, headaches, and difficulties with vision. These negative side effects threaten the safety and effectiveness of VE systems. Negative side effects have been found to develop in a variety of environments. The research focus on VE side effects thus far has been on the symptoms and not the causes. The main goals of this research is fourfold: 1) to compare a new measure for side effects with established ones; 2) begin analyzing the causes of side effects with an analysis of head-tracking; 3) to examine any adaptation that may occur within a session and between days of a session; and, 4) to examine possible predictors for users who may experience side effects. An experiment was conducted using two different VEs with either head-tracking on or head-tracking off over four days. A questionnaire, a balance test, a vision test, and magnitude estimations of side effects were used to assess the incidence and severity of sickness experienced in the VEs. Other assessments, including a mental rotation test, perceptual style, and a questionnaire on pre-existing susceptibility to motion sickness were administered. All factors were analyzed to determine what their relationships were with the incidence and severity of negative side effects that result from immersion into the VEs. Results showed that head-tracking induces more negative side effects than no head-tracking. The maze task environment induces more negative side effects than the office task environment. Adaptation did not occur from day to day throughout the four testing sessions. The incidence and severity of negative side effects increased at a constant rate throughout the 30 minute immersive VE sessions, but did not show any significant changes from day to day. No evidence was found for a predictor that would foretell who might be susceptible to motion sickness in VEs.
Assessing the Effects of Driving Inattention on Relative Crash Risk
Klauer, Charlie (Virginia Tech, 2005-11-07)
While driver distraction has been extensively studied in laboratory and empirical field studies, the prevalence of driver distraction on our nation's highways and the relative crash risk is unknown. It has recently become technologically feasible to conduct unobtrusive large-scale naturalistic driving studies as the costs and size of computer equipment and sensor technology have both dramatically decreased. A large-scale naturalistic driving study was conducted using 100 instrumented vehicles (80 privately-owned and 20 leased vehicles). This data collection effort was conducted in the Washington DC metropolitan area on a variety of urban, suburban, and rural roadways over a span of 12-13 months. Five channels of video and kinematic data were collected on 69 crashes and 761 near-crashes during the course of this data collection effort. The analyses conducted here are the first to establish direct relationships between driving inattention and crash and near-crash involvement. Relative crash risk was calculated using both crash and near-crash data as well as normal, baseline driving data, for various sources of inattention. Additional analyses investigated the environmental conditions drivers choose to engage in secondary tasks or drive fatigued, assessed whether questionnaire data were indicative of an individual's propensity to engage in inattentive driving, and examined the impact of driver's eyes off the forward roadway. The results indicated that driving inattention was a contributing factor in 78% of all crashes and 65% of all near-crashes. Odds ratio calculations indicated that fatigued drivers have a 4 times higher crash risk than alert drivers. Drivers engaging in visually and/or manually complex tasks are at 7 times higher crash risk than alert drivers. There are specific environmental conditions in which engaging in secondary tasks or driving fatigued is deemed to be more dangerous, including intersections, wet roadways, undivided highways, curved roadways, and driving at dusk. Short, brief glances away from the forward roadway for the purpose of scanning the roadway environment (e.g., mirrors and blind spots) are safe and decrease crash risk, whereas such glances that total more than 2 seconds away from the forward roadway are dangerous and increase crash risk by 2 times over that of more typical driving.
An Assessment of the Attention Demand Associated with the Processing of Information for In-Vehicle Information Systems (IVIS)
Gallagher, John Paul (Virginia Tech, 2001-04-25)
Technological interventions are being considered to alleviate congestion and to improve the quality of driving on our nation's highways. These new technology interventions will be capable of increasing the amount of information provided to the driver; therefore, steps must be taken to ensure they do not require a high attention demand. (Limited attention resources can be diverted from the primary task of driving to a secondary in-vehicle task). The attention demand required as part of the process of extracting information has been studied relatively extensively. However, the processing required to make complex decisions is not well understood and provides cause for concern. This study investigated the attention demand required to perform several types of tasks, such as selecting a route, selecting the cheapest route, and selecting the fastest route. The three objectives of this study were: 1) To investigate driver performance during IVIS tasks that required additional processing of information after the extraction of information from a visual display. 2) To develop a method for evaluating driver performance with regard to safety. This task was accomplished by performing an extensive review of the literature, and developing two composite measures. 3) To provide descriptive data on the proportion of drivers who exceeded a threshold of driver performance for each of the different IVIS tasks. An instrumented vehicle, equipped with cameras and sensors, was used to investigate on-road driver behavior on a four-lane divided road with good visibility. A confederate vehicle was driven in front of the instrumented vehicle to create a vehicle following situation. Thirty-six drivers participated in this study. Age, presentation format, information density, and type of task were the independent variables used in this study. Results from this study indicate that a high proportion of drivers' will have substantially degraded performance performing IVIS tasks such as selecting a route or a hotel from several possibilities. Findings also indicate that tasks involving computations, such as selecting the quickest or cheapest route, require a high attention demand and consequently should not be performed by a driver when the vehicle is in motion. In addition, text-based messages in paragraph format should not be presented to the driver while the vehicle is in motion. The graphic icon format should be utilized for route planning tasks.
Attentional demand evaluation for an automobile moving-map navigation system
Dingus, Thomas A. (Virginia Tech, 1987)
A study was undertaken to test and evaluate the human factors design aspects of an automobile moving-map navigation system. The primary objective of the study was to assess the driver attentional demand required by the navigation system during vehicle operation. A secondary objective of the study was to assess design specifics and determine whether or not the design was optimal in terms of efficiency of use in an automotive environment. Thirty-two driver-subjects drove a specially instrumented 1985 Cadillac Sedan de Ville on public roadways for this research. A cross-section of driver-subjects (both genders, ages 18 to 73, and driving experience from 2,000 to 40,000 miles per year) participated, and a cross·section of roadway types (residential, two-lane state route, and limited·access four-lane) and traffic conditions (light and moderate) were used as part of this research. The driver-subjects were asked to perform a variety of tasks while operating the research vehicle. These tasks included navigation tasks normally performed while using the navigation system, as well as a wide variety of conventional automotive tasks (e.g., tuning the radio or reading the speedometer) normally performed during vehicle operation. The purpose of asking the driver-subjects to perform a variety of conventional automotive tasks was so that direct comparisons in attentional demand could be made between tasks performed daily in an automotive environment and the navigation tasks. Twenty-one performance and behavioral measures were collected and analyzed for this research. These measures included eye—scanning and dwell-time measures, task-completion-time measures, and a variety of measures indicating driver performance and behavior. The data analyses for these measures focused on two major goals. First, the analyses determined which tasks (both navigator and conventional) required the highest attentional demand. Second, the analyses were used to determine groups of tasks which, for all practical purposes, required equivalent attentional demand. The results of the analyses indicated that the navigation system is a relatively effective device, useful for its intended purpose. The results also indicated that a number of design improvements are required, however, to optimize the safety and efficiency of the device. An iterative process of design improvement and further research into the effects of improved design on required attentional demand is therefore recommended.
Auditory localization of in-vehicle crash avoidance warnings as a cue to hazard direction
Tan, Adrian K. (Virginia Tech, 1996)
A human factors experiment was conducted to determine the effects of warning sound type, speaker location, and age on the ability to localize the direction of warning sounds in a passenger vehicle. The purpose of these warning sounds is to alert a driver of potential roadway hazards detected by an in-vehicle crash avoidance warning device. Auditory localization of the warning sound was investigated as a means of indicating hazard locations relative to the vehicle. Four dependent variables were measured— response time, decision time, accuracy, and azimuth—to assess the speed and accuracy of localizing six different warning sounds from each of sixteen speaker locations. The six warnings were found to be appropriate for crash avoidance warning applications through a previous study. The localization task was performed in the passenger compartment of a stationary 1995 Ford Taurus sedan. Subjects input their responses through a joystick. The results of the study suggest that the implementation of localized auditory crash avoidance warnings could be beneficial in the timely identification of hazard locations in the vehicle environment. People can quickly localize the general direction of warning sounds (= 1 s to 1.5 s); however, localization effectiveness depends on the proper choice of warning sound and speaker location. Otherwise, potentially serious problems can occur if poor choices are made. The study was successful in identifying sounds and speaker locations that performed best and provides recommendations for speaker placement for each of six potential hazard directions for the vehicle tested.
Auditory-Based Supplemental Information Processing Demand Effects on Driving Performance
Biever, Wayne Joseph (Virginia Tech, 1999-06-13)
Thirty-six drivers of both genders from three different age groups performed auditory cognitive tasks while driving an instrumented vehicle. The tasks were of two types. The first type of task was the selection of a driving route from a list presented as a recorded sound. These tasks represented the use of In-Vehicle Information Systems (IVIS). The second type of task consisted of a conversation like series of questions designed to replicate the use of a cellular telephone while driving. The IVIS tasks consisted of two levels of information density (short-term memory load) and four element types (complexity levels) including listening, interpretation, planning, and computation. The effects of age, information density, and element type on driving performance were assessed using a composite set of performance measures. Primary measures of driving performance included lateral tracking, longitudinal control and eye glances. Secondary task performance was assessed by task completion time, skipped tasks and task errors. Additionally, subjective assessment was done using a situational awareness probe question and a modified NASA-TLX question set. Results showed that drivers demonstrated a general decrease in their ability to maintain their lateral position with increased task complexity. Additionally, speed and following distance were less stable during tasks. During tasks, drivers glanced less at their mirrors and instruments and left their lane more often than during baseline driving periods. Even during difficult tasks, drivers had high self-confidence in their awareness of surroundings. One result of particular interest was an increase in lane deviations and headway variance coupled with increased forward eye glance durations. It is believed that this is evidence of a condition called "Cognitive Capture" in which a driver, though looking more extensively at the forward roadway, is having difficulty tracking the lead vehicle and lane position. High cognitive load is causing the driver to disregard or shed visual information to allow processing of auditory task-related information. Another result of concern is the inability of drivers to assess their own impairment while performing in vehicle tasks. During tasks drivers demonstrated reduced scanning of mirrors and vehicle instrumentation. This clearly demonstrates reduced situational awareness. Additionally, during tasks lane tracking and headway maintenance performance decreased as well. However, during all tasks drivers assessed their workload higher than baseline driving even though they rated it near the bottom of the scale. Also, drivers perceived no decrease in their situational awareness. The results of this study show that driving performance can be negatively impacted by even fairly simple cognitive tasks while a driver is looking at the road with their hands on the wheel. Even while viewing the road, a driver may perform an auditory task and be cognitively overloaded to the point of safety concerns. An additional concern is that drivers underestimate the degree of their cognitive load and its impact on their driving performance.
A comparison between predictive and formative cost-effectiveness evaluation techniques for the assessment of lecture and computer-based multimedia training
Neale, Vicki L. (Virginia Tech, 1996)
In an effort to validate a predictive (as opposed to a traditional formative or summative) cost-effectiveness model, a study was conducted to evaluate Kearsley and Compton's (1981) Benefits Model. Costs were input into the model as they applied to the design, development, and dissemination of two training programs on the topic of teaching individuals how to detect the level of drowsiness of their colleagues during team operations. The benefits of the training programs were identified, classified, and quantified as they applied to two media: lecture and computer-based multimedia. The experimenter identified the training system parameters, training benefits, and operational benefits. Then, for the predictive approach, the relationships between training system parameters, training benefits, and operational benefits were classified based on expert opinion. Quantification concerned the assignment of values (-1 or +1) based on expert opinion. The costs to design, develop, and disseminate the training programs were determined based on the parameters of the project. Finally, based on all information present, experts determined which of two training programs would be the most cost-effective to disseminate. To determine the accuracy of the Benefits Model as a predictive assessment tool, the same identified training system parameters, training benefits, and operational benefits were evaluated from a traditional formative evaluation approach. An empirical evaluation was conducted for the two training programs and a determination of the most cost-effective training medium was made. The data collected in the traditional formative evaluation approach was then compared to the experts' ratings and choice of training programs. For both the predictive and formative evaluation approach to determining cost-effectiveness, the computer-based multimedia was chosen as the most cost-effective training medium. However, for the predictive approach, the experts’ choice was based either solely or heavily on dollar amounts associated with design, development, and dissemination, while the data obtained through the validation process were given little or no weight. All experts stated that it would not have been possible to use the information gathered through application of the Benefits Model to determine cost-effectiveness with any confidence.
Contributing Factors to Run-off-road Crashes and Near-crashes
McLaughlin, Shane B.; Hankey, Jonathan M.; Klauer, Charlie; Dingus, Thomas A. (United States. National Highway Traffic Safety Administration, 2009-01)
The purpose of this investigation is to identify factors associated with run-off-road (ROR) crashes. Events from the 100-Car Naturalistic Driving Study that constituted ROR crash or near-crash events were investigated to identify conditions in which the events occurred and contributing factors. ROR events occur more frequently per mile in low-visibility (including darkness) and low-friction conditions than in clear and dry conditions. Approximately half of the events (56%) occurred on straight roadways, with the remainder occurring in curves (30%) and intersection turns (14%). The most frequently identified contributing factor among the ROR events was distraction. Changes in roadway boundaries (e.g., discontinuities) also appear to be a common factor. Short following distances appear to be more commonly a factor than lead-vehicle braking. Other factors include fatigue/impairment, low friction, vehicle encroaching on the subject vehicle, low-speed maneuvering errors, and late route selection.
Crowd-sourced Connected-vehicle Warning Algorithm using Naturalistic Driving Data
Noble, Alexandria M.; McLaughlin, Shane B.; Doerzaph, Zachary R.; Dingus, Thomas A. (2014-08-25)
A Dataset of Vehicle and Pedestrian Trajectories from Normal Driving and Crash Events in One Year of Virginia Traffic Camera Data
Bareiss, Max G. (Virginia Tech, 2023-06-07)
Traffic cameras are those cameras operated with the purpose of observing traffic, often streaming video in real-time to traffic management centers. These camera video streams allow transportation authorities to respond to traffic events and maintain situational awareness. However, traffic cameras also have the potential to directly capture crashes and conflicts, providing enough information to perform reconstruction and gain insights regarding causation and remediation. Beyond crash events, traffic camera video also offers an opportunity to study normal driving. Normal driver behavior is important for traffic planners, vehicle designers, and in the form of numerical driver models is vital information for the development of automated vehicles. Traffic cameras installed by state departments of transportation have already been placed in locations relevant to their interests. A wide range of driver behavior can be studied from these locations by observing vehicles at all times and under all weather conditions. Current systems to analyze traffic camera video focus on detecting when traffic events occur, with very little information about the specifics of those events. Prior studies into traffic event detection or reconstruction used 1-7 cameras placed by the researchers and collected dozens of hours of video. Crashes and other interesting events are rare and cannot be sufficiently characterized by camera installations of that size. The objective of this dissertation was to explore the utility of traffic camera data for transportation research by modeling and characterizing crash and non-crash behavior in pedestrians and drivers using a captured dataset of traffic camera video from the Commonwealth of Virginia, named the VT-CAST (Virginia Traffic Cameras for Advanced Safety Technologies) 2020 dataset. A total of 6,779,726 hours of traffic camera video was captured from live internet streams from December 17, 2019 at 4:00PM to 11:59PM on December 31, 2020. Video was analyzed by a custom R-CNN convolutional neural network keypoint detector to identify the locations of vehicles on the ground. The OpenPifPaf model was used to identify the locations of pedestrians on the ground. The location, pan, tilt, zoom, and altitude of each traffic camera was reconstructed to develop a mapping between the locations of vehicles and pedestrians on-screen and their physical location on the surface of the Earth. These physical detections were tracked across time to determine the trajectories on the surface of the Earth for each visible vehicle and pedestrian in a random sample of the captured video. Traffic camera video offers a unique opportunity to study crashes in-depth which are not police reported. Crashes in the traffic camera video were identified, analyzed, and compared to nationally representative datasets. Potential crashes were identified during the study interval by inspecting Virginia 511 traffic alerts for events which occurred near traffic cameras and impacted the flow of traffic. The video from these cameras was manually reviewed to determine whether a crash was visible. Pedestrian crashes, which did not significantly impact traffic, were identified from police accident reports (PARs) as a separate analysis. A total of 292 crashes were identified from traffic alerts, and six pedestrian crashes were identified from PARs. Road departure and rear-end crashes occurred in similar proportions to national databases, but intersection crashes were underrepresented and severe and rollover cases were overrepresented. Among these crashes, 32% of single-vehicle crashes and 50% of multi-vehicle crashes did not appear in the Virginia crash database. This finding shows promise for traffic cameras as a future data source for crash reconstruction, indicating traffic cameras are a capable tool to study unreported crashes. The safe operation of autonomous vehicles requires perception systems which make accurate short-term predictions of driver and pedestrian behavior. While road user behavior can be observed by the autonomous vehicles themselves, traffic camera video offers another potential information source for algorithm development. As a fixed roadside data source, these cameras capture a very large number of traffic interactions at a single location. This allows for detailed analyses of important roadway configurations across a wide range of drivers. To evaluate the efficacy of this approach, a total of 58 intersections in the VT-CAST 2020 dataset were sampled for driver trajectories at intersection entry, yielding 58,180 intersection entry trajectories. K-means clustering was used to group these trajectories into a family of 45 trajectory clusters. Likely as a function of signal phase, distinct groups of accelerating, constant speed, and decelerating trajectories were present. Accelerating and decelerating trajectories each occurred more frequently than constant speed trajectories. The results indicate that roadside data may be useful for understanding broad trends in typical intersection approaches for application to automated vehicle systems or other investigations; however, data utility would be enhanced with detailed signal phase information. A similar analysis was conducted of the interactions between drivers and pedestrians. A total of 35 crosswalks were identified in the VT-CAST 2020 dataset with sufficient trajectory information, yielding 1,488 trajectories of drivers interacting with pedestrians. K-means clustering was used to group these trajectories into a family of 16 trajectory clusters. Distinct groups of accelerating, constant speed, and decelerating trajectories were present, including trajectory clusters which described vehicles slowing down around pedestrians. Constant speed trajectories occurred the most often, followed by accelerating trajectories and decelerating trajectories. As with the prior investigation, this finding suggests that roadside data may be used in the development of driver-pedestrian interaction models for automated vehicles and other use cases involving a combination of pedestrians and vehicles. Overall, this dissertation demonstrates the utility of standard traffic camera data for use in traffic safety research. As evidence, there are already three current studies (beyond this dissertation) using the video data and trajectories from the VT-CAST 2020 dataset. Potential future studies include analyzing the mobile phone use of pedestrians, analyzing mid-block pedestrian crossings, automatically performing roadway safety assessments, considering the behavior of drivers following congested driving, evaluating the effectiveness of work zone hazard countermeasures, and understanding roadway encroachments.
Determining the Effectiveness of the Usability Problem Inspector: A Theory-Based Model and Tool for Finding Usability Problems
Andre, Terence Scott (Virginia Tech, 2000-04-03)
The need for cost-effective usability evaluation has led to the development of methodologies to support the usability practitioner in finding usability problems during formative evaluation. Even though various methods exist for performing usability evaluation, practitioners seldom have the information needed to decide which method is appropriate for their specific purpose. In addition, most methods do not have an integrated relationship with a theoretical foundation for applying the method in a reliable and efficient manner. Practitioners often have to apply their own judgment and techniques, leading to inconsistencies in how the method is applied in the field. Usability practitioners need validated information to determine if a given usability evaluation method is effective and why it should be used instead of some other method. Such a desire motivates the need for formal, empirical comparison studies to evaluate and compare usability evaluation methods. In reality, the current data for comparing usability evaluation methods suffers from a lack of consistent measures, standards, and criteria for identifying effective methods. The work described here addresses three important research activities. First, the User Action Framework was developed to help organize usability concepts and issues into a knowledge base that supports usability methods and tools. From the User Action Framework, a mapping was made to the Usability Problem Inspector; a tool to help practitioners conduct a highly focused inspection of an interface design. Second, the reliability of the User Action Framework was evaluated to determine if usability practitioners could use the framework in a consistent manner when classifying a set of usability problems. Third, a comprehensive comparison study was conducted to determine if the Usability Problem Inspector, based on the User Action Framework, could produce results just as effective as two other inspection methods (i.e., the heuristic evaluation and the cognitive walkthrough). The comparison study used a new comparison approach with standards, measures, and criteria to prove the effectiveness of methods. Results from the User Action Framework reliability study showed higher agreement scores at all classification levels than was found in previous work with a similar classification tool. In addition, agreement using the User Action Framework was stronger than the results obtained from the same experts using the heuristic evaluation. From the inspection method comparison study, results showed the Usability Problem Inspector to be more effective than the heuristic evaluation and consistent with effectiveness scores from the cognitive walkthrough.
Developing a Teen Driving Meta-Database Using Three Naturalistic Teen Driving Studies Plus Driver Coach Study
Klauer, Charlie; Hua, Lesheng; Dingus, Thomas A. (2024-01-25)
Motor vehicle collisions are the leading cause of death for teens aged 16 to 19. The risk of motor vehicle crashes is higher among teens aged 16 to 19 than among any other age group. Despite great interest in teen risky driving, little objective information about its prevalence is available. The Naturalistic Teenage Driving Study (NTDS), conducted at the Virginia Tech Transportation Institute (VTTI), provided a rich and powerful dataset, which permits researchers to evaluate driving performance over long periods and provide objective measures of driving risks and contributing factors. However, the NTDS only had 42 novice drivers from southwest Virginia. With the lack of other naturalistic studies of novice teenage driving for comparison, its findings are tentative and need further exploration and confirmation. More NDSs are needed to obtain additional crash data and determine what factors could lead to teen risky driving. Using the trigger thresholds from the NTDS, event databases were created from the Supervised Practice Driving Study (SPDS), the SPDS Attention Deficit and Hyperactivity Disorder (ADHD) Cohort NDS, the Second Strategic Highway Research Program (SHRP 2) NDS, and the Driver Coach Study. Similarly, a database of baseline epochs, per guidelines from the NTDS, was also developed for each of these studies. All event and baseline databases from all five studies were combined into one database to perform meta-analyses using naturalistic teenage driving data. This database is the most complete naturalistic teenage driving database in the world. Many of the key analyses that were performed on only 42 teenage drivers in the NTDS can now be performed on 489 novice drivers from seven locations around the U.S. In this report, we describe each database briefly, including the ADHD teen study, and provide notations about purpose, methods, measures, and instrumentation. We then review what have learned from each database about young driver crash risk. Studies based on the meta-database mainly focused on the prevalence of teen secondary task engagement, distraction, risky driving behavior, and progression of driving skill, as well as the associated crash risks for these behaviors. New projects and new work that this tool has already yielded are described herein, and additional work that still needs to be done is outlined.
Developing Guidelines for Designing Child Safety Printed Educational Materials: A User-Centered Approach
Stevens, Suzanne L. (Virginia Tech, 2003-04-11)
Motor vehicle crashes are the leading cause of unintentional injury-related death among children ages 14 and under and of these children who were fatally injured more that 60 % were not using safety restraints at the time of the collision. Children who are too large for child safety seats are often restrained improperly or not at all. In addition, many children are being shifted from child safety seats to adult safety belts prematurely. For proper protection, children who have outgrown child safety seats require booster seats combined with vehicle lap/shoulder belts. A booster seat raises a child up so that the lap and shoulder belts fit properly. The current research went through a systematic approach, from several perspectives, to develop an effective pamphlet to increase behavioral compliance of purchasing a booster seat. The pamphlet developed throughout these studies had a substantial and positive effect on intention and perceived control as well as a meaningful and substantial impact on actual purchase behavior. In addition, the associated guidelines that were developed allow others to produce effective printed educational materials. This research consisted of five studies described below. Study 1 consisted of 43 subject matter experts who were used to determine pertinent information that should be included in a complete booster seat pamphlet. Nine of the 20 items showed significance and were included in the first iteration of the pamphlet. Study 2 consisted of 5 parents of children who should be in booster seats and were not at the time of the study, evaluated the usability of the first iteration pamphlet. A total of 18 items were changed in the pamphlet and a subsequent second iteration of the pamphlet was developed. Study 3 consisted of 30 parents of children who should be in booster seats and were not at the time of the study, were used to assess the comprehensibility (Cloze test), hazard-risk judgments (carefulness ratings), and understandability (questionnaire) of three booster seat pamphlets. Significance was found for the second iteration pamphlet in both comprehensibility and understandability, but no significance was found in risk perception. Study 4 consisted of 8 human factors graduate students who were used to assess the reading level (SMOG test), instructional design and inclusion of learning principles (BIDS-3 test), and readability (RAINS test) of three booster seat pamphlets. The second iteration pamphlet and two existing industry pamphlets were used in Studies 3 and 4 and significance was found for the second iteration pamphlet in both instructional design and learning principles as well as readability and was the only pamphlet to have a reading level under 8th grade. Subsequent to these studies a third iteration of the new pamphlet was developed. Study 5 consisted of 45 parents of children who should be in booster seats and were not at the time of the study. Three booster seat pamphlets, two from the child passenger safety industry and the third iteration pamphlet were used as treatments (15 participants per group). Effectiveness of the intervention was tested by assessing three variables, intent to purchase (revealed that when intent was high purchase was high), perceived control of purchasing (revealed that when perceived control was high purchase was high), and actual purchase behavior (third iteration pamphlet showed a significantly higher purchase rate than the industry pamphlets). Of the 19 participants who purchased a booster seat, there were 12 (63%) in the third iteration pamphlet group, 2 (11%) in the alternate 1 pamphlet group, and 5 (26%) in the alternate 2 pamphlet group, and 100% of those who purchased, reported that they use them each time their child rides in a vehicle. This research increased our understanding of information design and well as generating general design guidelines for pamphlets. In addition, this research produced a pamphlet for credible sources to use as an education tool for parents who have children who should be in booster seats and are not placed in them when riding in a vehicle.
Development of a Threat Assessment Algorithm for Intersection Collision Avoidance Systems
Doerzaph, Zachary R. (Virginia Tech, 2007-11-27)
Relative to other roadway segments, intersections occupy a small portion of the overall infrastructure; however, they represent the location for nearly 41 % of the annual automotive crashes in the United States. Thus, intersections are an inherently dangerous roadway element and a prime location for vehicle conflicts. Traditional safety treatments are effective at addressing certain types of intersection safety deficiencies; however, cumulative traffic data suggests these treatments do not address a large portion of the crashes that occur each year. Intersection Collision Avoidance Systems (ICAS) represent a new breed of countermeasures that focus on the types of crashes that have not been reduced with the application of traditional methods. Incursion systems, a subset of ICAS, are designed to specifically undertake crashes that are a result of the violation of a traffic control device. Intersection Collision Avoidance Systems to address Violations (ICAS-V) monitor traffic as it approaches the intersection through a network of in-vehicle sensors, infrastructure- mounted sensors, and communication equipment. A threat-assessment algorithm performs computations to predict the driver's intended intersection maneuver, based on these sensor inputs. If the system predicts a violation, it delivers a timely warning to the driver with the aim of compelling the driver to stop. This warning helps the driver to avoid a potential crash with adjacent traffic. The following dissertation describes an investigation of intersection approach behavior aimed at developing a threat assessment algorithm for stop-sign intersections. Data were collected at live intersections to gather infrastructure-based naturalistic vehicle approach trajectories. This data were compiled and analyzed with the goal of understanding how drivers approach intersections under various speeds and environmental conditions. Six stop-controlled intersection approaches across five intersections in the New River Valley, Virginia area were selected as the test sites. Data were collected from each site for at least two months, resulting in over sixteen total months of data. A series of statistical analysis techniques were applied to construct a set of threat assessment algorithms for stop-controlled intersections. These analyses identified characteristics of intersection approaches that suggested driver intent at the stop sign. Models were constructed to predict driver stopping intent based on measured vehicle kinematics. These models were thoroughly tested using simulation and evaluated with signal detection theory. The overall output of this work is a set of algorithms that may be integrated into an ICAS-V for on-road testing.
Development of Human Factors Guidelines for Advanced Traveler Information Systems and Commercial Vehicle Operations: Literature Review
Dingus, Thomas A.; Hulse, Melissa C.; Jahns, Steven K.; Alves-Foss, J.; Confer, S.; Rice, A.; Roberts, I.; Hanowski, Richard J.; Sorenson, D. (United States. Federal Highway Administration, 1996-11)
The purpose of Task A was to conduct a literature review of human factors-applicable articles associated with Advanced Traveler Information Systems (ATIS) and ATIS-related commercial vehicle operations (CVO) systems. Specifically, Task A was to assess existing human factors guidelines to determine their applicability to ATIS systems and identify research gaps that would be filled to establish complete and comprehensive ATIS guidelines. As with any literature review, the conduct of Task A was treated as a foundation for subsequent tasks. The duration of Task A (3 months) was such that some of the literature of interest could not be obtained prior to publication of this document. Thus, the literature review does not, in effect, end with this report.
Development of Human Factors Guidelines for ATIS and CVO Identify Strengths and Weaknesses of Alternative Information Display Formats
Hulse, Melissa C.; Dingus, Thomas A.; Mollenhauer, Michael A.; Liu, Y. C.; Jahns, Steven K.; Brown, T.; McKinney, B. (United States. Federal Highway Administration, 1993-10)
This report is one of a series produced as part of a contract designed to develop precise, detailed, human factors design guidelines for Advanced Traveler Information Systems (ATIS) and Commercial Vehicle Operations (CVO). The goals of the work covered in this report were to: (1) identify information format alternatives for ATIS devices for both private drivers and CVO applications, and (2) identify research issues that must be addressed in order to develop effective information format guidelines. To achieve these goals, and to make the greatest progress possible toward the ultimate project goal of guideline development, the project developed the strategy of turning the current state of knowledge into tools applicable to any ATIS design. Four primary design-decision tools were developed. These tools are intended to help either professional or nonprofessional human factors designers make appropriate tradeoff decisions in designing effective ATIS displays. The four tools are: (1) Sensory Modality Allocation, (2) Trip Status Allocation, (3) Display Format Allocation, and (4) Display Location.
Development of models for detection of automobile driver impairment
Dingus, Thomas A. (Virginia Tech, 1985-08-05)
Two of the leading causes of automobile accidents are driver impairment due to alcohol and drowsiness. Apparently, a relatively large percentage of these accidents occur because drivers are unaware of the degree to which they are impaired due to these sources. The purpose of this research was to develop models which could detect driver impairment due to alcohol, drowsiness, or the combination of alcohol and drowsiness, and which could be practically implemented in an automobile. Such detection models, if successfully implemented in conjunction with a system to warn an impaired driver of his or her condition, could potentially save hundreds of lives each year. Six driver-subjects operated a computer controlled driving simulator during each of four conditions. The four conditions consisted of a control condition, an alcohol condition, a sleep-deprived condition, and a combination alcohol and sleep-deprived condition. Moderate levels of alcohol and sleep deprivation were used for this study. Nineteen performance and behavioral measures were collected during this study. Each measure was evaluated singly and in combination with other measures to determine potential value for detection of driver impairment. Detection models were then formulated using the most promising detection measures. The results indicated that a useful on-board drowsiness impairment detection device is possible and practical for highway driving. This device would also, in all likelihood, provide useful detection information regardless of whether low to moderate amounts of alcohol were present in a drowsy driver. The results also showed that on-board alcohol impairment detection may be possible at moderate to high BAC.
Display Technology and Ambient Illumination Influences on Visual Fatigue at VDT Workstations
Bangor, Aaron W. (Virginia Tech, 2000-12-19)
The concept of "visual fatigue" has been studied for 70 years or more. In that time, no single metric of measuring visual fatigue nor one agreed-upon set of tasks to induce visual fatigue has been settled upon. Not even a robust definition of visual fatigue has been established. This research worked to solve some of those problems. This research first set out to develop an index of visual fatigue that could be used effectively in quantifying the subjective experience of visual fatigue. Then it sought to create a set of measurable tasks, representative of office work, that would induce visual fatigue. Taking these two developments, an experiment using human participants was conducted to validate these developments and work toward solving two issues in the visual fatigue field: how visual display technology and ambient illumination affect the onset of visual fatigue. A 4x4 within-subjects design was developed and executed to study how these two independent variables affected ratings of visual fatigue, performance on the task battery, subjective image quality judgments, and contrast sensitivity shifts. Two cathode ray tube (CRT) and two active-matrix LCD (AMLCD) monitors were used in this study. While many instances of the monitors as a whole caused significant differences in reports of visual fatigue, performance, subjective image quality, and contrast sensitivity loss, only a slight effect of display technology was found. Four of eleven visual fatigue and two of eight subjective image quality dimensions showed that the LCD monitors induced more visual fatigue and were rated poorer than the CRT monitors. Ambient illumination levels of 0, 300, 600, and 1200 lux affected all four groups of dependent variables. On the whole, lighting caused visual fatigue, with "watery eyes" and "glare from lights" being adversely affected by brighter lighting. The 0 and 1200 lux were associated with the worst performance, while 300 lux was associated with the best performance. Subjective image quality was affected by lighting, with increasing lighting causing bothersome screen reflections and more temporal (e.g., flicker and jitter) distortions; 600 lux induced more reports of image sizing anomalies. Finally, it caused significantly worse shifts at the 6.0 c/deg spatial frequency on the contrast sensitivity test. The data show that lighting of 300 lux is the best of these four illumination levels. The results of this study not only contribute to the body of research in the areas of display technology and ambient illumination, but several developments of this research are offered to the research community: a complete survey metric of visual fatigue, a standardized battery of tasks for studying visual fatigue and image quality, and a comprehensive subjective image quality survey.
Do Real-time and Post Hoc Feedback Reduce Teen Drivers' Engagement in Secondary Tasks?
Hua, Lesheng; Ankem, Gayatri; Noble, Alexandria; Baynes, Peter; Klauer, Charlie; Dingus, Thomas A. (National Surface Transportation Safety Center for Excellence, 2023-08-02)
In 2020, 2,800 teens in the United States between the ages of 13 and 19 were killed in motor vehicle crashes (Centers for Disease Control and Prevention, 2023). The purpose of this study is to assess if there is an additional benefit to the driver feedback system implemented in the Driver Coach Study (Klauer et al., 2017) on secondary task reduction and if the same trends of parental involvement are observed. The data used in this study were drawn from two previously completed naturalistic driving studies involving teenage drivers. The Driver Coach Study recruited 90 teen-parent dyads and presented the teen driver with feedback on their driving performance for the first 6 months (Klauer et al., 2017). Parents were able to review a website that provided information on the feedback that their teen received. The Driver Coach Study data were compared to the Supervised Practice Driving Study, which observed 88 teenage drivers during naturalistic driving in the same geographic location who did not receive feedback. Novice driver secondary task engagement was recorded. Parental involvement was examined by tracking which teen/parent groups checked the website and which did not. Results suggest that teen drivers who received feedback were overall less likely to engage in secondary tasks as well as less likely to multitask than those teen drivers who did not receive feedback. Additionally, females generally engaged in secondary tasks more often than males. Teen drivers whose parents logged in to the feedback website also reduced their engagement in some secondary tasks but not all. Unfortunately, no significant reduction in cell phone use was observed between teen drivers who received feedback and those who did not. Overall, the results suggest that further research should be conducted, as monitoring and feedback for teen drivers does reduce overall secondary task engagement.

Browsing by Author "Dingus, Thomas A."

Results Per Page

Sort Options