729 research outputs found
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Influence of Riding Experience on Glance Behavior, Brake Response Time and Deceleration Rates by Drivers and Motorcyclists
No full textThe focus of the research was to address the crash avoidance behaviors of drivers versus motorcyclists. Avoidance tasks include, attention maintenance and hazard anticipation measured with glance behaviors, and hazard mitigation measured with response times and deceleration. Specifically, where might the driver behavior be similar or different than that of a motorcyclist? The performances of 23participants were analyzed while they drove a car and rode a motorcycle over the same low-volume, open roads. Participants wore eye-tracking equipment used to record eye-glance information while the motorcycle and car were instrumented with an on-board accelerometer and GPS apparatus. Operators also responded by braking quickly to a stop when an LED, mounted in front of them, was illuminated. Motorcyclists spent less time glancing toward the road ahead and made fewer last-glances toward the direction of most threatening traffic before turning when riding the motorcycle, as opposed to when driving a car. Additionally, motorcyclists’ response times were similar to those when driving, yet motorcyclists decelerated less sharply compared to drivers. These results suggest that riders may be exposing themselves to unnecessary risk. Specifically, motorcyclists frequently failed to make proper glances and practice optimal riding techniques. The implication of these results relative to a training curriculum is discussed
An Analysis of Driver Reactions to Tire Failures Simulated with the National Advanced Driving Simulator (NADS)
No full textAnalyses of real-world tire tread belt detachment and/or sudden air loss events as well as vehicle testing of those events have been presented in scientific literature since the 1990’s. These confirm that such tire failures are complex and semi-random events that produce numerous sensory feedback cues to real-world drivers. These analyses further demonstrate that vehicles representing a full spectrum of steering characteristics are typically controllable and are controlled by drivers both during and after the tire disablement event. In 2003, the National Highway Traffic Administration (NHTSA) sponsored a study using the National Advanced Driving Simulator (NADS) to evaluate the technical hypothesis that there is a correlation between vehicle linear range understeer gradient and the likelihood of control loss when subject drivers experience a simulated tread belt detachment. The NADS subjects “drove” three simulated “vehicles” with different understeer gradients in a simulated tread separation even. The study’s authors reached conclusions regarding the drivers’ ability to control the “vehicles” which were inconsistent with real-world research. This paper presents an analysis of the NADS study performed to identify possible causes of the conflicting results and provides commentary upon several deficiencies noted in the NADS vehicle/tire modeling and validation. A more comprehensive understanding of the reported driver reactions when viewed in light of real vehicle experiments, real-world data, and an understanding of the limitations of the simulations is provided
Attention Factors Compared to Other Predictors of Simulated Driving Performance Across Age Groups
No full textGroups of young, middle-aged, and older adults performed a battery of computer-based attention tasks, the UFOV® and neuropsychological tests, and simulated low-speed driving in a suburban scenario. Results from the attention tasks were submitted to Maximum Likelihood factor analysis and 6 factors were extracted that explained more than 57% of the task variance. The factors were labeled speed, switching, visual search, executive, sustained, and divided attention in descending order of amount of task variance explained. The factor scores were used to predict simulated driving performance. Step-wise regressions were computed with driving performance as the criterion, and age, sex and the factor scores, the UFOV® scores, or the neuropsychological test scores as predictors. Results showed that the perceptual-motor speed and divided attention measures from the UFOV® and attention battery were more likely to explain driving performance variance than the neuropsychological tests
Encouraging Environmentally Friendly Driving Through Driver Assistance: The eCo Move Project
No full textA questionnaire study was conducted in order to identify relevant driver motives and assistance options for environmentally-friendly driving. Eighteen participants rated items belonging to the three factors time, environment, and consumption, and subsequently evaluated three types of driver assistance systems. Results concerning the motives showed that older drivers (above the age of 65) focused significantly less on the time motive, whereas high annual mileage drivers tended to focus more on the time motive compared to low annual mileage drivers. Small vehicle drivers emphasized more on the environment motive compared to middle-class/van drivers. In terms of the driver assistance options for eco-friendly driving, a display of the current consumption rate through colorcoding received the highest number of first place rankings in the category intelligent vehicle information systems. A function that automatically shuts off the engine after a certain stopping time, as well as optimal gear choice and time to shift, were ranked high in the category intelligent advanced driver assistance systems. In the category intelligent navigation systems, a traffic- and situational adaptive navigation system was ranked the highest most often. Assessment of drivers’ preferences additionally showed that most participants preferred the assistance functions to provide visual information as opposed to direct intervention. The results concerning the driver groups and their underlying driving motives as well as the preference statements will be used to inform the design and development of assistance functions for promoting eco-driving within the European eCo Move project
Use of Instrumented Motorcycle to Measure the Effectiveness of Malaysian Rider Training: A Pilot Study
No full textA pilot study used an instrumented motorcycle to evaluate riding performances of Malaysian learner riders graduating from rider training and licensing program. 105 participants were asked to ride the instrumented motorcycle along a predefined route (mean 8 KM) in a mixed traffic environment. Period of turn signal activation and deactivation, maneuvering speed and deceleration of participants at unsignalized T junctions were measured as riding performances. Significant differences between male and female riders in responding to oncoming vehicles at the junctions were observed. Significant effects of age were also found in period of turn signal activation and maneuvering speed. Implications for current rider training are discussed
A Driving Simulator Study to Examine the Role of Vehicle Acoustics on Drivers’ Speed Perception
No full textIn recent years, there has been a desire by vehicle manufacturers to reduce the in-cab noise of vehicles, in order to improve driver comfort and enhance the enjoyment of in-vehicle entertainment systems. This reduction of incab noise is accompanied by policy initiatives to reduce transport related noise by implementing low noise road surfaces. However, it is not known how such reductions in the availability of auditory cues affect drivers’ ability to judge speed, and there is a danger that drivers will increase their speed, to compensate for the absence of auditory cues. In this study, drivers were required to maintain speed at 30 and 70 mph, in the absence of a speedometer, with and without accompanying vehicle noise. Results showed that drivers’ ability to maintain the correct speed profile was much more variable in the absence of accompanying vehicle noise and this variation was found to be higher when drivers were asked to travel at higher speeds of 70 mph. Drivers were also found to travel faster than the required speed in the absence of vehicle noise, although their ability to maintain speed was generally worse at 70 mph, even in the presence of auditory cues
Impact of Cognitive Workload on Physiological Arousal and Performance in Younger and Older Drivers
No full textTwo groups, aged 25-35 and 60-69, engaged in 3 levels of a delayed auditory recall task while driving a simulated highway. Heart rate and skin conductance increased with each level of demand, demonstrating that these indices can correctly rank order cognitive workload. Effects were also observed on speed and SD of lane position, but they were subtle, nonlinear, and did not effectively differentiate. Patterns were quite consistent across age groups. These findings on the sensitivity of physiological measures replicate those from an onroad study using a similar protocol. Together, the results support the validity of using these physiological measures of workload in a simulated environment to model differences likely to be present under actual driving conditions
The Effect of Traffic Complexity and Speed on Young and Elderly Pedestrians’ Street-Crossing Decisions
No full textThis experiment aimed at studying the effects of age, traffic complexity and speed of the approaching cars on the probability of a pedestrian to be involved in a crash. Fifty nine participants aged between 20-84 years took part in a street-crossing estimation task in a simulated road environment. The results showed an overall higher number of ‘collisions’ with increasing age. While the number of collisions did not vary according to traffic complexity and speed of the approaching cars in the young group, the older participants were more likely to make decisions that led to collisions when the traffic was approaching from two rather than one direction, and at a high speed. The findings were discussed in relation to the effects of age-related cognitive and perceptual limitation on difficulties in selecting safe gaps. The present results have implications for improving older pedestrians’ safety in terms of road design, speed reduction measures, and training opportunities
Cognitive, Perceptual and Motor Decline as Predictors of Risky Street-Crossing Decisions in Older Pedestrians
No full textOlder pedestrians are well known to be over-involved in road crashes compared to younger pedestrians. This study investigates the extent to which risky street-crossing decisions in older pedestrians can be explained by agerelated declines of cognitive, perceptual and physical abilities. Three age groups of participants (young, young-old, old-old) were evaluated in a street-crossing task and performed a series of functional tests. The results showed that agerelated slowing in walking speed as well as a decline in cognitive flexibility and in visual acuity play a substantial role in risky decisions by the elderly. The implications of these findings, particularly in the development of a mixed physical-cognitive training to enhance the older pedestrians’ road crossing decisions in complex environments, are discussed
On-Road Driving Assessment Errors Associated with Pass and Fail Outcomes for Older Drivers with Cognitive Impairment
No full textMost on-road assessments do not make use of standardized scoring to determine driver safety. The current study sought to find a subset of driving errors that were related to on-road Pass and Fail outcomes in a group of 60 older drivers with cognitive impairment, and that were also considered important contributors to a Fail outcome by the driving specialist occupational therapist who administered the assessment. A number of useful errors were found that suggest that even a non-standardized driving assessment could incorporate a short list of driving errors that may assist in the determination of driving ability