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Do In-Vehicle Advance Signs Benefit Older and Younger Driver Intersection Performance?
Get PDFAn experimental study was conducted to determine if intersection behavior of those 18 to 24 and 65+ benefited from advanced in-vehicle signs presented in a head-up display (HUD) format. The University of Calgary Driving Simulator (UCDS) was used to determine whether intersection performance improved in the presence of several advanced signs or whether unwanted adaptive behaviors occurred (e.g., increasing speed to run the light instead of stopping). Invehicle signs facilitated an increase in stopping occurrences for both younger and older drivers at intersections with relatively short yellow onsets. In addition, eye movement analysis revealed significant age effects with regard to vertical and horizontal gaze variablity, with younger drivers showing increases in vertical gaze variability compared to the older drivers. Younger drivers also looked more often and had longer percentage of durations fixating on the HUD compared to the older drivers
Innovative Fatigue Management Approach in the Trucking Industry
Get PDFDriver fatigue, recognized as a major safety problem in the transportation industry, is strongly influenced by employee work and sleep schedules. The work and rest hours of truck drivers have been regulated by Hours-of-Service (HoS) rules in the U.S since 1938, but it has become increasingly apparent these rules are inconsistent with the science of sleep and fatigue. We present and assess an innovative alternative safety management system, which takes a pro-active, science-based complimentary approach. This Risk-Informed Performance-Based (RIPB) safety system for sleep and fatigue management was implemented at one major trucking company, and involved the training of managers and dispatchers on scientific aspects of work assignments and a regular feedback system that assessed the fatigue risk of the work schedules. Driver fatigue was assessed using the Circadian Alertness Simulator (CAS) software system for simulating sleep and alertness based on work-rest patterns (Moore-Ede et al., 2004). Each driver was assigned a cumulative fatigue risk score based on logbook data processed for multiple one-month periods before and after the implementation of the safety management system. The implementation of the RIPB safety management system resulted in a significant reduction of fatigue risk scores, a reduction of the rate and costs of accidents, and improvement of other operational parameters. The success of the RIPB system was sustained over an extended time period of more than three years, and thus could permit the relaxation of overly prescriptive HoS regulations
Steering Entropy Changes as a Function of Microsleeps
Get PDFThis study aimed to assess steering entropy as a measure of decrements in driving performance caused by microsleeps. Microsleeps are brief, unintended episodes of loss of attention that last 3-14 seconds. These episodes, which are frequent in drivers with sleep disorders, can be long enough to impact steering performance and are particularly disruptive when driver action is imperative, as when driving around curved highway segments. Steering entropy is a driver-centered performance measure that can detect drivers’ corrective responses to situations when the vehicle state falls outside the driver’s expectations. This study tests the hypothesis that steering entropy is an indicator of increased erratic steering behavior during microsleep episodes in drivers with obstructive sleep apnea/hypopena syndrome (OSAHS). Twenty-four drivers with OSAHS were used in this study and their electroencephalography (EEG) defined microsleep (cases) and non-microsleep episodes (crossover control) were compared using a case-crossover method. The performance measure, steering entropy, was calculated from a time-series history of steering angle data. Steering entropy was compared for each microsleep in the three-second interval both immediately preceding and immediately following each microsleep. Results showed that steering entropy was higher on curves during microsleeps and post microsleeps when compared to straight road segments and the no-workload baseline condition. This suggests that steering entropy can capture erratic steering behavior, allowing us to better understand how drivers correct for previous steering errors
Variability of Driving Performance During Microsleeps
Get PDFThis study aimed to evaluate the value of measuring microsleeps as anindicator of driving performance impairment in drowsy drivers with sleepdisorders. Drivers with sleep disorders such as obstructive sleep apnea/hypopenasyndrome (OSAHS) are at increased risk for driving performance errors due tomicrosleep episodes, which presage sleep onset. To meet this aim, we tested thehypothesis that OSAHS drivers show impaired control over vehicle steering, laneposition and velocity during microsleep episodes compared to when they aredriving without microsleeps on similar road segments. A microsleep is defined asa 3-14 sec episode during which 4-7 Hz (theta) activity replaces the waking 8-13Hz (alpha) background rhythm. Microsleep episodes were identified in theelectroencephalography (EEG) record by a neurologist certified by the AmericanBoard of Sleep Medicine. Twenty-four drivers with OSAHS were tested usingsimulated driving scenarios. Steering variability, lane position variability,acceleration and velocity measures were assessed in the periods during amicrosleep, immediately preceding (pre) microsleep, and immediately following(post) microsleep. In line with our introductory hypothesis, drivers with OSAHSdid show significantly greater variation in steering and lane position during themicrosleep episodes compared to the periods pre and post microsleep. The resultsindicate that identification of microsleep episodes can provide a marker fordeclining vehicle control of drivers with OSAHS
Drivers' Perception of and Response to Brake Failure
No full textThe behaviour and emotional state of 48 drivers was investigated during both servo booster and hydraulic circuit brake failures on a proving ground. Results suggested that the most informed and least “stressed” drivers seemed to be the most successful in bringing the test vehicle to a safe stop. The interpretation of these results fed into a study using a driving simulator. Interventions were examined that tested both the “engineering” of the vehicle to a more stringent interpretation of current legislation and driver “information” with a novel visual/auditory warning system. Targeting the vehicle, not the driver, seemed to the best way to manage the rare event of brake failure
Aggressive Driving is a Major Cause of Traffic Accidents and Road Rage in Jordan
Get PDFMotor vehicle accidents are a major cause of death among Jordanians. Roughly 700 people died last year in car accidents out of a total population of five million people. Many factors contribute to this. Some involve planning, design, construction, operation, surface condition, and policing of the roadways. The most deadly factor is human error. This includes unawareness of traffic rules and roadway condition; lack of driving skills; poor judgment; failure to interact and adjust to prevailing roadway conditions; and most importantly, aggressive driving. Preliminary findings of a survey questionnaire conducted in this study show that improper engineering design, inadequate traffic control, lack of traffic management, and traffic congestion are the main factors leading to aggressive driving and road rage on Jordan roadways. The study includes 200 questionnaires. The main objective of this study is to identify aggressive driving behaviors in Jordan and underline their effect on traffic safety. In addition, the study attempts to increase drivers’ awareness of their actions on the roadway and point out the consequences associated with these actions. Many drivers justify their aggressive driving as temporary retaliatory measures to counteract other aggressive drivers, and therefore, this leads to road rage and traffic chaos. Aggressive driving behaviors such as pushing a car off the roadway, deliberate obstruction of passing vehicles, pursuing a vehicle, excessive high speed, and tailgating are considered at the top of the list according to the study findings. Most drivers admit that driving 20km/hr above speed limit causes danger to pedestrians but not to other vehicles
On the Fast Lane to Road Rage
Get PDFAggressive driving and road rage are increasing. The factors that trigger road rage are not well understood. The first goal of this study was to identify conditions likely to lead to aggressive driving/road rage. The second goal was to develop a paradigm that allows for the controlled study of road rage in the laboratory setting. A total of forty-five drivers participated in the study. Twenty-three drivers received non-contingent instructions that emphasized safely driving to a rest stop. The remaining drivers received contingent instructions that added a $10 monetary incentive if they arrived at the rest stop in the top 50% of all drivers. Participants drove in two scenarios (regular / irregular flow) in a high fidelity driving simulator. We recorded cardiovascular reactivity while driving, and measured driving-related anger after completing each scenario. Overall, the driving task evoked minimal changes in blood pressure. However, an incentive by gender interaction for systolic blood pressure (SBP) reactivity indicated that males in the contingent incentive condition displayed greater SBP responses than males in the noncontingent incentive condition or females in the contingent incentive condition. Contingent versus non-contingent incentives had no effect on females’ SBP response. We found no effect of incentive or traffic flow on anger, though analysis on an individual level indicated that some subjects were affected by the manipulation of driving condition. The present findings provide psychophysiological evidence that driving under time pressure and in irregular traffic flow may contribute to the genesis of road rage
A Systemic Model for Driver-in-Control
Get PDFModels of driving have traditionally been couched either in terms of guidance and control or in terms of human factors. There is, however, a need for more powerful models that can match the rapidly growing complexity and sophistication of modern cars. Such models must provide coherent and consistent ways of describing driver performance to help engineers develop and validate technical concepts for semi- and fully automated systems in cars. This paper presents a qualitative model for Driverin-Control (DiC) based on the principles of cognitive systems engineering. The model describes driving in terms of multiple, simultaneous control loops with the joint driver-vehicle system (JVDS) as a unit. This provides the capability to explain how disturbances may propagate between control levels. The model also enables new functions to be evaluated at the specific level at which they are aimed, rather than by their effects on global driving performance
Effects of Cell Phone Conversation Difficulty on Driving Performance
Get PDFThe literature has shown that conversations and verbal tasks degrade the driver’s ability to maintain control of the vehicle and avoid hazardous conditions. However, the question of how the difficulty (or intensity) of a conversation relates to decrements in driving performance needs further investigation. Other studies have shown that conversations may hinder driving, but these were unable to quantify a difficulty threshold at which conversations and verbal tasks became more hazardous. This study compared two quantifiably different levels of conversation difficulty and a non-conversing condition over measures of driving performance and mental workload. This study used a GlobalSim Corporation driving simulator, allowing participants full control of the vehicle on two lane roads in a rural setting. Driving conditions were set up and controlled in order to determine the extent to which conversation had an effect on driving performance, which was assessed in terms of steering and speed-maintenance ability and the ability to deal with hazardous situations. We compared driving performance when participants were not conversing to when they were conversing, as well as whether a more difficult conversation had a greater effect on performance than an easier one. Participants conversed with the experimenter over a hands-free headset. Conversations consisted of answering and conversing based on either easy (“small talk”) or difficult (“thought provoking”) questions. Participants drove a simulated car for approximately thirty minutes, with ten minutes devoted to driving under each of the conversation conditions (no talking, easy conversation, difficult conversation). During each of the ten minute driving sessions, participants were exposed to one of three hazardous events: an ambulance running a red light in front of the driver, an oncoming car swerving into the driver’s lane, and a parallel-parked car pulling out in front of the driver. A variety of variables were measured in the categories of speed maintenance (accelerator position variability, speed variability, average speed), lane position maintenance (steering offset, average lateral speed), crash avoidance (collisions, response time to hazardous events), and mental workload (RSME). Two double multivariate ANOVAs were conducted, and then planned contrast analyses were used to test how the conversation levels affected each dependent measure. While concurrently driving and conversing, participants had higher variation in their steering and speed than when driving without conversing. While driving and conversing, participants also drove at slower average speeds and reported having to exert higher mental effort. No significant differences between conversation and non-conversation conditions were found for collisions or response time to hazards. When comparing the difficult and easy conversation conditions, the only significant difference in driving performance was for speed variation—participants showed more speed variation during difficult than during easy conversations. The findings from this study suggest that having a conversation over a hands-free phone while driving may cause decrements in steering and speed maintenance performance. Also, people thought that talking on a cell phone while driving was more mentally demanding than driving while not talking. These findings suggest that regardless of conversation intensity, driving performance will be affected by this attentional distraction both through actual decrements in performance as well as in perceived distraction from the driving task. It seems to be something about the act of talking, as opposed to the content of the material, that is detrimental to driving performance. This is consistent with other research (Briem & Hedman, 1995; Irwin, Fitzgerald, & Burg, 2000; McKnight & McKnight, 1993) that has found effects for conversations but little or no effect of varying conversational difficulty
Naturalistic Driving: User and Task Analysis
Get PDFCognitive Task Analysis and methods for analyzing Naturalistic Decision Making are powerful tools that can be applied to transportation research. In conjunction with simulators, these methods allow increased understanding of real user interactions with their in-vehicle systems, and the decision processes involved in the operational aspects of driving, navigating, and using infotainment support systems. Adopting this approach facilitates investigation of driver performance under a range of workload and stress conditions, which supports future development of a prototypical model that will encapsulate the cognitive and perceptual-motor demands of driving in the presence of situational stressors under both high- and low-workload conditions