729 research outputs found
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In-Vehicle Noise Alters the Perceived Meaning of Auditory Signals
No full textResearch on driver perception and interpretation of auditory signals has generally been conducted under conditions of low-to-moderate ambient in-cab noise. In a series of four experiments, the effects of various ambient noise conditions on the perceived meaning of auditory signals were investigated. Noise conditions that may be realistically anticipated in the course of normal driving altered the perceived urgency and meaning of signals. The presence and extent of such changes was a function of the specific auditory signal, the ambient noise condition, and their interaction. The results indicate that in-vehicle auditory signal design criteria developed only under low-to-moderate ambient noise conditions are not likely to be sufficient. The significant signal-by-ambient noise interaction further suggests that multiple noise backgrounds must be considered
Assessing Cognitive Distraction Using Event Related Potentials
No full textThis report examines the utility of using Event-Related Brain Potentials (ERPs) to evaluate cognitive distraction in the context of driving an automobile. Across two studies, ERPs (both P300 latency and P300 amplitude) were found to be effective in quantifying the cognitive workload experienced by drivers when they interact with in-vehicle voice-command systems
The Long-Term Effectiveness of Eco-Driving Training: A Pilot Study
No full textEco-driving has been proven to have a great benefit in reducing vehicle fuel consumption in many developed countries. However, the potential of ecodriving on energy-saving in China is not very clear. Taking three taxi drivers from Beijing Beiqi Taxi Group Company as examples, the petrol consumption, travel distance and many other factors influencing vehicle fuel use before and after ecodriving training were collected through survey forms. The short-term and long-term effect of eco-driving was compared. The results showed that, taking one month as the statistical cycle, the benefit of eco-driving in saving fuel consumption averaged is 19.04%; while it reduced to 14.41% after four months from taking eco-driving training. Thus, drivers would partially regressed back to less economically driving behaviors and thus resulting in lower fuel savings after sometime. This study laid a foundation to evaluate the benefit of eco-driving in saving energy use
The Role of Attention in Increasingly Autonomous Driving
No full textTrent is Senior Technical Leader Crash Avoidance at Volvo Cars Safety Centre, and Adjunct Professor at Chalmers University of Technology in Gothenburg, Sweden. At Volvo Cars his role is to identify and define future leading edge safety needs within crash avoidance. His role provides leadership in safety analysis and research, supporting development of safety requirements and strategies and to drive human related aspects of safety design in a broader perspective, using the possibilities with new active safety functions and systems. For example he is responsible for safety in Volvo's self-driving car program Drive Me. At Chalmers, he is very active in the analysis of naturalistic driving data at SAFER Vehicle and Traffic Safety Centre at Chalmers, where he recently was PI for a SHRP2 S08 naturalistic driving risk analysis of driver inattention
Effects of Non-Verbal Communication Cues on Decisions and Confidence of Drivers at an Uncontrolled Intersection
No full textDrivers read other drivers’ intentions using various non-verbal communication cues in situations where traffic regulations play only a limited role. Although such communication is important to reach safe joint actions with other driver(s), effects of communication have not been fully understood. The objective of this study was to understand effects of communication cues on driver’s decisions and confidence. Straight-cross-path and left-turn scenarios around an uncontrolled intersection were studied in an interview-based experiment using 65 subjects. The subject’s car approached the intersection while another car was approaching the same intersection and sent communication cues consisting of various combinations of vehicle behaviors (constant speed, speeding up, and slowing down) and hand gestures (meaning “Go ahead” and “Stop”). Computer animations of the scenarios were presented to the subjects and terminated before the two cars reached the intersection. The subjects rated yielding frequency and confidence level for each cue combination in each scenario. The results showed that the vehicle behaviors and the hand gestures affected subjects’ yielding frequencies and confidence levels. The cues also interacted with the priority rule in the left turn scenarios. The hand gestures were especially effective to consolidate subjects’ decisions to yield or go with confidence when the priority rule was ineffective (i.e. in the straight-cross-path scenarios). The hand gestures were also effective to change the yielding frequencies to accept the cues conflicting with the effective priority rule (i.e. in the left-turn scenarios). Some requirements and recommendations for autonomous vehicle were discussed
The Effects of an Eco-Driving Interface on Driver Safety and Fuel Efficiency
No full textReal-time, in-vehicle guidance on eco-driving is likely to produce substantial improvements in vehicle fuel economy. However, the benefits of such in-vehicle systems should be achieved without impairing driver safety. A simulator study evaluated both visual and haptic eco-driving feedback systems, which provided advice on gas pedal usage. Hill driving scenarios with variable traffic density were used to test drivers’ prioritization of safe and fuel-efficient driving. A visual, second-order display and a haptic force feedback gas pedal created the smallest errors in gas pedal usage and so maximized fuel efficiency. The visual display increased time spent looking away from the road, implying reduced driver safety. Participants were worse at eco-driving in more demanding, high traffic conditions. Drivers appeared to prioritize safety over eco-driving, however safety margins were shorter in the high density traffic condition, despite the degradation in eco-driving performance. The findings suggest which modality could be most appropriate for presenting in-vehicle eco-driving guidance, and hint that these systems should advise drivers based on the prevailing traffic conditions
Effects of Fatigue on Real-World Driving in Diseased and Control Participants
No full textThis study evaluated real world driver errors and sleepiness in 66 drivers with Obstructive Sleep Apnea (OSA) and 34 matched controls (24 younger and 22 older). Driving errors and driver state were derived from analyses of video data from “black-box” event recorders. Sleep fragmentation data in OSA was derived from actigraphy for 15 days prior to beginning standard treatment (positive airway pressure, PAP) and 15 days after beginning PAP treatment. Prior to starting PAP, OSAs appeared sleepier than controls in general and particularly at intersections, while making safety errors following nights with high levels of fragmented sleep compared to matched controls. Adverse effects of sleep fragmentation during the pre-PAP phase were reduced post-PAP. Greater hours of PAP-use were associated with lower sleepiness and errors on the road. PAP-use was associated with a decrease in high sleep fragmented nights. Findings suggest reduction in acute sleepiness is unlikely to be the only mediating factor that explains the driving safety benefits of PAP in OSA
The Role of System Training and Exposure on Crash Warning Evaluation
No full textThis research paper explores the role that familiarity with crash warning systems has on the evaluation of those systems. Prior research has not been consistent in it treatment of providing system training and exposure to participants. The potential impact of these differences in methodology on key measures of response and outcome is unknown. Ninety-six participants completed this study that crossed system training with prior exposure to the warning to systematically evaluate these effects for both forward crash warning (FCW) and lane departure warning (LDW) systems evaluations. Prior exposure to the alerts led to changes in engagement with the distraction task for both FCW and LDW events. Training on the system influenced outcomes of the FCW events with less severe outcomes for participants who were aware they had the system. There is also evidence that driver who were aware of the system’s presence but did not have prior exposure to it were less likely to complete the experiment successfully. The results of this study point to an advantage in not provide prior system awareness training in terms of longer commitment times to allow the crash warning events to materialize when prior exposure to the alerts is provided
Training Working Memory of Older Drivers: The Effect on Working Memory and Simulated Driving Performance
No full textThis study aimed to investigate in older drivers whether a working memory (WM) training would enhance WM, and whether improvement of WM transfers to enhanced driving ability. 54 older drivers participated in the study, but due to drop-out, 38 participants (mean age 70.34) remained in the sample. Participants were randomly assigned to a control (N=19) or an experimental condition (N=19). Each participant conducted a WM training during 25 days. During the pre-test and post-test, WM and driving ability were assessed. Results indicate that the training lead to an improvement of WM. In addition, there was an improvement of several driving measures, that was however independent of the level of WM improvement. These findings will be discussed
A Competence Based Exam for Prospective Driving Instructors: Construction, Validation, and Implications
No full textIn line with changed views on driver training and driver instructor preparation a competence-based instructor exam was introduced in the Netherlands. The exam consists of two parts: 1) multimedia theory tests, 2) a performance assessment. An implicit idea behind the innovated exam is that it can have a positive backwash effect on the quality of driver instructor preparation programs. This study aims to evaluate the reliability, validity and fairness of the theoretical tests, which appear in different versions across time. Data of 4741 prospective driving instructors, enrolled during the period between January 1010 and October 2012, were used for analysis. The results of IRT-analyses show that the theory tests yielded reliable and fair decisions, although misclassifications occurred across versions. The predictive validity of the theory tests for the final performance assessment was low. Implications for the design and maintenance of exam programs are discussed. Follow-up studies will focus on the question, whether the improved instructor exam contribute to safer drivers in the end