257 research outputs found
The Cost in Fatalities, Injuries and Crashes Associated with Waiting to Deploy Vehicle-to-Vehicle Communication
Today, the auto industry is ready to deploy vehicle-to-vehicle (V2V) communication-based
safety systems employing proven technology and well-developed standards. In fact, the
readiness entails more than just V2V, but potentially vehicle-to-everything (V2X)
communication, where everything (X) can include communication with other vehicles, the
roadway infrastructure, and vulnerable road users.The purpose of this white paper is not to assess the strength or weaknesses of either DSRC or C-V2X technology. Rather it is to investigate and quantify the lost opportunities to prevent light-vehicle crashes by waiting for the development and implementation of CV2X as opposed to mandating DSRC now in the form of FMVSS 150. The focus on V2V crashes, as opposed to all crashes, is based on significant levels of uncertainty associated with the deployment of infrastructure-based hardware and/or small-cell networks that would be required for either DSRC or C-V2X technologies to address many of the single vehicle crash types.https://deepblue.lib.umich.edu/bitstream/2027.42/147434/1/The Cost Associated with Waiting to Deploy DSRC 032018.pd
Trust-Fund Doctrine Revisited [Part I]
The foundation case in Amenca was an action to restore dividends paid out to shareholders by an insolvent bank, but from limited beginnings the trust-fund doctrine expanded to become a major legal weapon for corporate creditors under a wide variety of conditions. In this discussion we propose to treat separately three major aspects of the trust-fund problem: (1) the status of corporate insolvency, which was a condition precedent to the operation of the rule; (2) the rights of creditors against creditors; and (3) the rights of creditors against shareholders. Our analysis will be confined chiefly to the statutory and case law of the state of Washington with no attempt at detailed treatment of the rules of other courts beyond an incidental comparison. The Federal Bankruptcy Act is excluded from analytical discussion as deserving separate treatment. We undertake no more in that regard than to point out to the practitioner the possibility of using substantive state law to advantage in proceedings under the Federal Act. The body of case authority will be appraised in the light of the various state statutes which apply, and an attempt made to indicate the current place of the trust-fund doctrine in this jurisdiction
The effect of color contrast on daytime and nighttime conspicuity of roadworker vests
A static field study was conducted, both during the day and at night, to examine the effect that color contrast within a safety vest has on noticeability. Fluorescent orange and yellow fabrics were matched with orange, yellow, silver, or white retroreflective trim to appear similar to a safety vest. The method of paired comparisons was used to develop a linear scale of how noticeable the various color combinations appeared under cluttered and uncluttered viewing conditions.
The results indicate that color contrast within the safety vest, as well as relative to the environmental surround, affects judgments of noticeability. However, in the nighttime condition color contrast was not an identifiable attribute, as all the retroreflective materials used appeared white when illuminated. In the nighttime condition, the luminance of the retroreflective trim accounted for almost all of the variance in the noticeability judgments.
The results of this study suggest that a design for safety apparel that includes a combination of fluorescent yellow and fluorescent orange fabrics (providing color contrast for the daytime) with silver/white micro-prismatic retroreflective trim (proving high luminance for nighttime) is likely to be the most noticeable combination in both daytime and nighttime conditions.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/49418/1/UMTRI-2000-35.pd
The effect of width and separation in rear window defroster lines on the identification of obstacles
A static, indoor study was conducted to assess the effects of rear window defroster/defogger line width and separation on the identification of obstacles located to the rear of a motor vehicle. Additional independent variables included participant age, rake angle of the rear window, and target location in the rearward field of view. The targets used in this simulated backing/reversing task, as seen through the interior rearview mirror, were a trash can
(low contrast) and a child’s bicycle (high contrast). The dependent variables were reaction time to correctly identify the target, and subjective ratings of how easily targets could be seen through the simulated defroster/defogger line patterns.
There were two main findings. First, neither the width nor separation of the opaque lines affected participant reaction time to correctly identify a target, even when the percentage of the rearward view that was obscured by the lines reached 50%. Second, subjective ratings of the ease with which targets could be seen were significantly affected by both the width and separation of the defroster/defogger lines. These results suggest that drivers will object to the
increased width and decreased separation of lines before target identification is significantly affected.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/49399/1/UMTRI-99-12.pd
The effects of rear-window transmittance and backup-lamp intensity on backing behavior
A dynamic field experiment was conducted, both during the day and at night, to examine the effects of rear-window transmittance and backup-lamp intensity on driver backing behavior (stopping distance, velocity, acceleration, and trial duration) toward a known stationary object. In addition, three years of crash data from the General Estimates System (GES) file were examined for backing crashes. Specific variables of interest in the GES data were driver age, ambient light condition, and the type of passenger vehicle involved (car versus minivan or sport utility vehicle).
The results of the field experiment indicate that drivers do not adjust their backing behavior to variations in the amount of available light, at least under conditions where there is little uncertainty
regarding obstacles. However, drivers do appear to adjust their backing behavior as they grow older, for the most part driving more cautiously. Nevertheless, the crash data indicate that older drivers are still
over-represented in backing crashes. Minivans and sport utility vehicles, which are much more likely to have rear-window tinting, are also over-represented in backing crashes.
Based on the crash data, despite the findings of the field experiment, it is suggested that older drivers might benefit from higher-transmittance windows, higher-intensity backup lamps, and rearward
detection and warning devices. These same modifications might also benefit the drivers of minivans and sport utility vehicles.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/49443/1/UMTRI-2001-6.pd
Effects of color on the detection of retroreflective pedestrian markings by normal and color deficient drivers
A nighttime field study was conducted to assess the effects of color on the detection of retroreflective pedestrian markings by color normal and color deficient drivers. Participants seated in a stationary vehicle, with its low-beam headlamps on, indicated when a moving pedestrian, who wore colored retroreflective markings on her legs, was just detectable. Independent variables included color (red, yellow, green, and white), retroreflective power, participant
age, color-vision capability, and location of the stimulus in the visual field (centrally or peripherally located).
This experiment demonstrated that, for persons with normal color vision, the color of a retroreflective marking affects the distance at which a pedestrian, located in the central portion of the visual field, can be detected. This result is consistent with previous research for color normal individuals (Sayer et al., 1998). Specifically, colored retroreflective stimuli were detected at distances 3 to 6% greater than a photometrically matched achromatic
stimulus. Furthermore, the findings are qualitatively in agreement with the Helmholtz-Kohlrausch effect. Color deficiency had a measurable, although limited, influence on the effect of color on detection distance. The results with regard to central versus peripheral locations were not conclusive.
This study, as well as a related previous study (Sayer et al., 1998) indicated that, under the conditions of this experiment, color influences detection distance to a lesser extent than suggested by the color correction factors prescribed in ASTM E 1501. Tentatively, the discrepancy seems to be accounted for by the size of the retroreflective markings, in terms of visual angle, at the point at which drivers first detect or recognize them. The ASTM correction factors may be appropriate for larger visual angles, but smaller correction factors may be more appropriate if retroreflective markings can be expected to have very small visual angles (approaching point sources) at critical distances. However, the influence of color and its interaction with visual angle has not been fully characterized by this study or by the previous studies of retroreflective stimuli, and further research on the effects of color, SIA, and size is needed.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/49397/1/UMTRI-99-6.pd
The effects of hydrophilic and hydrophobic rear-window treatments on visual performance
This study consisted of a survey and a field experiment to evaluate the potential benefits of hydrophilic treatments for motor vehicle glazing. The survey examined the subjective
assessments of 15 drivers whose vehicles had a portion of the rear window and one of the side windows treated with a hydrophilic coating. The field experiment evaluated the effects of hydrophilic and hydrophobic treatments, relative to an untreated condition, on driver visual acuity under simulated wind and rain conditions, both during the day and during the night. Additional independent variables included whether headwind was present, rain rate, and age.
The results of the survey show that drivers did not report a benefit of hydrophilic treated areas compared to untreated areas of the side or rear windows. Consistent with the survey results, the field experiment showed that hydrophilic treatment did not improve visual performance. However, significant improvements in visual performance were associated with hydrophobic treatment of the rear window.
The findings from the field experiment support previous research that showed significant improvements in visual acuity associated with hydrophobic treatment of the windshield. On the other hand, the present study found no subjective or objective benefits of applying hydrophilic treatments to rear or side windows.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/49448/1/UMTRI-2001-21.pd
The influence of hydrophobic windshield coating on driver visual performance
This experiment evaluated potential benefits of hydrophobic coating of windshields under simulated conditions of use. The main independent variables were hydrophobic
treatment, participant age, and time of day. The dependent measures were minimum visual
angle resolved and response time. The results indicate that the hydrophobic coating improved visual performance, decreasing the minimum visual angle resolved by almost 34% and reducing the response time by more than one second. In practical terms, visual acuity improved in the treated-nighttime condition to approximately the level of acuity in the untreated-daytime condition.
This experiment showed that hydrophobic coatings can result in significantly improved
driver visual performance without negatively affecting response time. However, this experiment did not address the durability or longevity of these products, as the hydrophobic coating was only tested when it was newly applied (and therefore could be expected to be near peak performance). Benefits associated with hydrophobic coatings are likely to diminish with time and wear (more or less slowly depending on durability), unless the coating is reapplied.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/49362/1/UMTRI-97-31.pd
The effects of secondary tasks on naturalistic driving performance
Includes bibliographical references (p. 40)Data from 36 drivers involved in a naturalistic driving study were analyzed to determine the frequency and conditions under which drivers engage in secondary behaviors and to explore the relationship these behaviors might have with driving performance. A random selection of 1,440 five-second video clips of the drivers’ faces
was coded for the occurrence of specific secondary behaviors and the frequency and duration of glances. Corresponding performance data from the instrumented vehicles was used to calculate variability of steering angle, mean and variability of lane position, mean and variability of throttle position, and variability of speed. Contextual factors were also examined, including road type, road curvature, and road condition.
Drivers were observed engaged in secondary behaviors in approximately 34% of the clips. Conversation with passengers was the most common secondary behavior (15.3%), followed by grooming (6.5%) and using cellular phones (5.3%). Younger drivers were most likely to engage in secondary behaviors overall (42%). All categories of secondary behavior were associated with significantly higher variability in steering angle. The results for other performance measures were mixed. Cellular phone use, eating/drinking and grooming, resulted in increased steering variance, but did not affect lane position or speed variance. Cellular phone use was associated with the smallest percentage, and shortest mean duration, of glances away from the forward scene, but fewer glances could
negatively affect scanning of the roadway environment. However, conversations with passengers showed higher variability in steering angle, increased deviation for both lane position and distance from center of the lane.
In general, secondary behaviors are neither equal in frequency of occurrence nor in their effect on driving performance. Drivers appear to perform differently when taking part in different tasks, and appear to engage selectively in secondary behaviors according to traffic/roadway conditions. In naturalistic conditions, when drivers can freely choose whether or not to engage in secondary tasks, drivers may be performing secondary tasks when their driving skills are least needed and the traffic environment tends towards being less challenging based
upon a driver’s own assessment. These findings highlight the importance of conducting naturalistic studies, as it appears that controlled studies cannot always account for the full effects of driver choice and perceived risk associated with immersion in actual traffic/roadway environments.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/57450/1/99225.pd
The roles of garment design and scene complexity in the daytime conspicuity of high-visibility safety apparel
Includes bibliographical referencesA naturalistic field study was conducted to assess the effects of garment color, the amount of background material, pedestrian arm motion, scene complexity, and driver age on the daytime conspicuity of personal safety garments. Sixteen drivers drove instrumented vehicles in real traffic, along a fixed 31-km route, in search of pedestrians wearing one of four fluorescent safety garments with retroreflective trim. Distances at which the drivers first reported detecting the pedestrians were recorded. Drivers had no prior knowledge of where along the route pedestrians would be located, nor the number of pedestrians positioned along the route. All of the challenges normally encountered when driving on public roadways were present during the study (other motor vehicles, traffic signals, signs, pedestrians, and bicyclists), thus imposing an ecologically valid level of workload on the drivers.
The results show that scene complexity was the only main effects variable to significantly affect the distance at which a pedestrian wearing a fluorescent safety garment was detected. Garment color (fluorescent yellow-green or fluorescent red-orange), garment type (Class 2 vest or Class 2 jacket), arm motion (arms in motion or stationary), and driver age (younger or older) did not significantly affect the distance at which pedestrians were detected. The results contribute to a growing body of research aimed at a more general understanding of what garment characteristics enhance pedestrian conspicuity in both day and night conditions.Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/57445/1/98801.pd
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