729 research outputs found
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Validation of the Static Load Test for Event Detection During Hands-Free Conversation
Get PDFObjective. To see if visual event reaction times (RTs) during handsfree conversation conditions in the Enhanced Static Load Test (ESLT) can predict RTs in similar conditions in on-road driving. Methods. Brake reaction times to random center and side light events were measured while watching a driving video, attempting to keep a marker in the center of the lane with a steering wheel, answering the phone by pressing a button, and carrying on neutral or angry handsfree conversations in covert (silent) or overt mode on a hands-free phone device. Open-road tests were conducted in traffic for subjects with similar side and front light events, with foot reaction times measured while engaged in the same secondary tasks and conditions. Results. Mean RTs for the task segments in the lab were predictive of the mean RTs for the corresponding task segments in the on-road test (r = 0.90, df = 16, p < 0.000001). Conclusion. This study validates the Enhanced Static Load Test as predictive of visual event RTs during open-road driving for the range of experimental conditions and tasks considered
Assessment in Driving Simulators: Where We Are and Where We Go
Get PDFThis paper describes the mindset at the start of a three year project to develop a test on a driving simulator. It reviews the literature, presents background information on driver training simulators and their relation with assessment. It then introduces some of the ideas behind this project, the adaptive cognitive model that will be used, as well as the interoperable assessment module we will develop
Gender Effects on Lane Change Test (LCT) Performance
Get PDFThere are various easy-to-implement, low-cost methodologies for evaluating driver performance under distraction caused by in-vehicle tasks. One of them is the Lane Change Test (LCT), which is currently under consideration for becoming an ISO-standardized procedure. This paper investigates the effect of gender on LCT performance. Although a common procedure in psychological research, balancing for gender is not a requirement made by the ISO draft. However, using data from three LCT experiments, we found gender differences in LCT as well as secondary task performance. We conclude that subject samples balanced for gender are necessary to assure comparability of LCT results
Three Large Truck Crash Categories: What They Tell Us About Crash Causation
Get PDFLarge Truck Crash Causation Study (LTCCS) data is used to compare three categories of crash involvements: truck single-vehicle (SV) involvements, multi-vehicle (MV) involvements in which the truck has been assigned the critical reason (CR), and MV involvements in which the other vehicle (OV) has been assigned the CR. These three categories represent distinctly different causal contributions by truck drivers to the crash, with SV involvements having the greatest truck driver impairment and misbehavior. Surprisingly, paired comparisons of the three categories indicate that truck SV and truck-CR MV crash involvements were the most dissimilar in their causal profiles. Factors associated with truck SV crash involvements include non-use of safety belts, driver unfamiliarity with roadways, vehicle failures, lack of prior sleep, 16+ hours awake, and early morning driving. Dense traffic situations (e.g., rush hours) make trucks more likely to be at-fault in MV crashes. Many other factors were not associated with differences among the categories, suggesting no differential effect on truck driver safety performance, even though they might affect risk generally. Among fatigue-related factors, those related to sleep and alertness physiology were linked to SV crashes, while those related only to Hours-of-Service (HOS) work rules were not
An Invariant May Drive the Decision to Encroach at Unsignalized Intersections
Get PDFThis paper introduces a novel approach to understanding when and where drivers make the Go / No Go decision (not) to turn left and encroach upon an approaching car that has the right-of-way in an unsignalized intersection. The source of data is approximately 2,400 hours of video recordings at two intersections near Göteborg, Sweden. Automated image processing software extracted the trajectories of the pairs of cars involved in more than 14,000 left turns across traffic at the first intersection and 2,400 at the second. We subdivided the data into four different left-turn scenarios - where the approaching car arrives from the opposite direction, from the lateral direction, from the intended direction (merging), and while making its own left turn. For each scenario, we found the distances between the turning car and the approaching car at the time when we can assume the decision (not) to turn is made and conducted logistic regressions to identify the distances associated with the 50/50 acceptance probabilities for the decision (not) to turn. We also calculated the resulting encroachment distances (‘trailing buffers’) for every decision to turn. We expected to find wide variability in these buffers. Instead, we observed separations that were virtually the same across scenarios at each intersection but differed across intersections. Tacit, intersection-dependent knowledge of this invariant may drive the decision of whether or not to turn and encroach. We discuss the implications this finding has for the design of in-vehicle active safety systems
Comparison of the Effects of Two Push-to-Talk Button Implementations on Driver Hand Position and Visual Attention
Get PDFButtons built into the steering wheel are used in many vehicles as push-to-talk (PTT) buttons for in-car speech user interfaces. We explore the influence of such a fixed PTT button on driver hand position on the steering wheel and on visual attention while driving. We also explore these variables for a wireless PTT glove, which allows drivers to use the entire surface of the steering wheel to operate the PTT button. Participants in our driving simulator-based study were willing to take advantage of the flexibility in hand position afforded by the glove PTT button. We also found that participants cast glances toward the steering wheel significantly less often when using the PTT glove than they did when operating the fixed PTT button
Enhanced Seat Belt Reminder Systems for Teenage Drivers and Passengers
Get PDFFailure to use a seat belt is a significant highway safety concern for teenagers. The current Federally-required seat belt reminder system is limited in its effectiveness, and many automobile manufacturers are now providing enhanced seat belt reminder (ESBR) systems. Current systems are designed for the general driving public and their design must represent a trade-off between effectiveness in promoting belt use and consumer acceptance. Teens may respond differently to system features and trade-off considerations may be different for risk-prone teens. This study conducted research to evaluate teen driver and passenger reactions to a variety of ESBR systems and features. The study was conducted in an operational, but stationary vehicle, with simulated drives. Systems and features were evaluated regarding their likelihood of increasing belt use, annoyance, signal appropriateness, desirability, and other aspects. Discussion groups were also held with the parents of teen drivers. Based on findings of the experiment and discussions, a set of recommendations was developed for the design of optimal ESBR systems oriented toward teen drivers and their passengers
How Well Do Drivers Understand Their Own Headlights?
Get PDFThe current research represents an initial investigation of drivers’ understanding of high beam and low beam headlight patterns in a nighttime driving environment. Fifty-four university students used a highlighter to indicate on a paper diagram of a roadway scene the portion of the scene that they felt their headlights would illuminate. Although the headlight patterns produced by participants varied more than expected, several consistent patterns emerged. Classification and evaluation of these drivers’ responses revealed that many drivers misunderstand the area of the roadway that is illuminated by their headlights. These misunderstandings fall into fairly distinct patterns. The results indicate many drivers possess an incomplete understanding of the pattern of illumination provided by their headlights. These results are consistent with earlier evidence that many road users fail to appreciate the visibility challenges that exist at night
Implementation of a Driving Diary Intervention to Reduce Aberrant Driving Behaviours
Get PDFCrash data involving taxis indicates that such drivers are over represented in crashes and are one to two times more likely to be involved in a fatality crash. This study reports on the pre intervention survey to provide a baseline measure of the self-reported attitudes and corresponding driving behaviours of a sample of taxi drivers. Results indicate that some taxi drivers willingly admit to engaging in unsafe driving practices. In addition, preliminary results of a post intervention survey revealed that taxi drivers’ safety perceptions, attitude and behaviours improved after completing a Driving Diary intervention
Manipulating Drive Characteristics to Study the Effects of Mental Load on Older and Younger Drivers
Get PDFA driving simulator was used to assess performance in younger and older drivers (M ages 18 and 71 years). The impacts of three challenges were assessed: visibility (clear day, fog), traffic density (low, high) and wayfinding (no challenge, drivers challenged to use signs and landmarks to find their destination). Performance was measured in terms of hazard RT, collisions, wayfinding errors (missed or extra turns), and driving speed. The challenge manipulations produced interactive effects and age was a factor in some of these interactions. Older drivers missed more turns in wayfinding but overall they performed as well or better than younger drivers and reduced their speed more to driving challenges