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Visibility aid cycling clothing: Flashing light-emitting diode (FLED) configurations
Abstract
Purpose
– The purpose of this paper is to investigate drivers’ differing psychological perceptions of cyclists’ conspicuity according to active visibility aid configurations on clothing.
Design/methodology/approach
– The flashing light-emitting diodes (FLEDs) were positioned on the major joints (shoulders, elbows, wrists, hips, knees, and ankles) in eight configurations and pre- and post-surveys were conducted.
Findings
– The results indicated that there were significant differences among the eight configurations in observers’ detection and recognition of cyclists, contributions of FLEDs, and visibility of cyclists ( p <0.001). Among the eight different configurations on joints, FLEDs on the hips, knees, and ankles were the most detectable, recognizable, and visible.
Originality/value
– Most of the previous studies have investigated passive visibility aids and there is a lack of research on FLED configurations on major joints for cyclists. Thus, this study is expected to be beneficial to designers when developing active visibility aid clothing for cyclists.
... Lee [12] designed a cycling jacket incorporating solar powered LED (light emitting diodes) sensor lights in order to improve visibility. Koo and Huang [13] tested different configurations of flashing LEDs on cycling clothes to the psychological perception of drivers. Kgatuke et al [14] developed a cycling jacket integrated with LEDs. ...
... Literature showed that the usage of flashing LEDS can improve the recognition of cyclist in the dark. Koo and Huang's study [13] suggested to put the flashing LEDs on the lower garment at hip, knee and ankle. But also, the LED configuration on the top wear took good scores. ...
Cycling is a popular sport which is preferred by all age groups all around the world. As it is an active sport, it requires special types of clothing to provide comfort to the wearer. In spite being a healthy activity, cycling can result with acute or chronic injuries. In this study, an extensive survey was conducted to the cyclists in order to reveal their preferences of cycling clothes, their requirements, their accidental experiences and safety needs. By considering the survey results, optional designs of a more protective and functional cycling top wear were outlined. In order to avoid from acute injuries which were stated to be in the shoulder and arm areas the most, a para-aramid and spacer/silicon foam supported design was proposed. Also, the visibility was enhanced by the implementation of active lightening on the front and back sides of the clothing.
... Bicyclists are often not sufficiently conspicuous to drivers (Rasanen & Summala, 1998), and efforts should be taken to enhance their rear conspicuity when cycling in daylight conditions. Bicycle taillights can provide conspicuity benefits for bicyclists (Blomberg et al., 1986;Edewaard et al., 2017;Edewaard et al., 2018;Edewaard et al., 2020;Koo & Dunne, 2012;Koo & Huang, 2015;Matthews & Boothby, 1980;Watts, 1984). While taillights are conventionally mounted to the seat post, taillights have the potential to be more effective when mounted elsewhere on the bicycle or rider. ...
... In other words, taillights that are mounted to the seat post of the bicycle with or without lights on the rider's heels can help observers to recognize the presence of the bicyclist from farther distances. This finding adheres to the results of similar studies that assessed the benefits of taillights on bicyclist daytime and nighttime conspicuity (e.g., Blomberg et al., 1986;Edewaard et al., 2017;Edewaard et al., 2018;Edewaard et al., 2020;Koo & Dunne, 2012;Koo & Huang, 2015;Matthews & Boothby, 1980;Watts, 1984). ...
Bicyclists risk being involved in collisions with motor vehicles, even during daytime. Thus, bicyclists who ride in daylight must enhance their conspicuity. This study assessed the daytime conspicuity benefits of bicycle taillights using eye tracking technology. Participants were driven along an open-road route while wearing an eye tracker and pressed buttons when they detected and recognized a test bicyclist. Participants encountered the bicyclist displaying one of four taillight configurations, and the distances from which they responded to the test bicyclist were recorded. The results revealed that, after participants first glanced at the bicyclist, a significant amount of time was needed to detect and recognize the bicyclist. Further, seat post-mounted lights displayed with or without lights mounted to the heels of the rider’s shoes provided the greatest conspicuity advantage in terms of recognition. This experiment offers useful insights into the optimal light placement options for bicyclists to enhance their daytime conspicuity.
... The invention is more concerned with society, reducing injuries during accidents, safeguarding the lives of the people, protecting animals (minimizing the usage of leather), motivating interdisciplinary projects, and preferably for the wellbeing of humans [7]. Most research in motorcyclist clothes is related to development the helmet [8], to improving the visibility [9,10] and safety [11] of bicyclists. Some papers report the effect of protective clothing on wear comfort [12,13]. ...
In recent years motorcycling becomes more and more popular. It is known that even in relatively warm weather, moving air is cooler and constant exposure to wind when riding may cause a chilling effect that leads to hypothermia. Motorcyclists may lose the ability to concentrate and react on changing traffic conditions when they have hypothermia. We propose the use of electric heating elements in the jacket so that motorcyclist comforts increase. This element receives the energy from the worked engine of the motorcycle. It is located between the two fabrics layers (top and lining) and is made of nichrome wire. The heating is carried out by connecting this element with the power supply system of the motorcycle. In research, we use two types of packages that differ by top fabrics and two connection circuits. The studies were carried out in three different environmental conditions (air temperature, wind speed, and air humidity). Standard test methods were used for performance testing. The effectiveness of electric heating elements used in underwear space for increasing the thermal properties of motorcyclist clothing is proven. It was established that the use of an electric heating element is effective only with a thermocontroller in the electrical circuit. The results of our investigation confirmed the effectiveness of electric heating elements being used in motorcyclist jackets.
... A growing body of literature indicates that bicycle taillights provide conspicuity benefits for bicyclists while riding at night (Edewaard et al., 2017;Koo & Dunne, 2012;Koo & Huang, 2015;Watts, 1984). In terms of daytime conspicuity, Edewaard et al. (2019) conducted a closed road study in which participants rated the extent that each bicyclist among an array of four bicyclists was recognizable as a bicyclist. ...
... Although Wood et al. (2012) found no significant difference between the recognition distances of flashing and steady headlight, this comparison has never been studied empirically using bicycle taillights (which are red and less intense than headlights). With regard to taillight placement, studies have consistently found that placing lights or retroreflective material on major joints (e.g., knees, and ankles) can enhance bicyclist conspicuity (e.g., Blomberg, Hale, & Preusser, 1986;Koo & Dunne, 2012;Koo & Huang 2015;Stapleton, Stapleton, Koo, & Koo, 2017;Wood et al., 2012). Indeed, there is a growing body of literature that supports the concept of biological motion ("biomotion"; Johansson, 1973); humans' perceptual sensitivity to discriminating human joint movement patterns (for a review, see Tyrrell, Wood, Owens, Whetsel Borzendowski, and Stafford Sewall, 2016). ...
A total of 729 bicyclist fatalities and approximately 50,000 bicyclist injuries were reported in the United States in 2014. Of the bicyclist fatalities, roughly 50% involved crashes that occurred at civil twilight or after dark (National Center for Statistics and Analysis, 2016). Also regarding bicyclist fatalities, Hutchinson and Lindsay (2009) found that the majority of bicyclists’ deaths resulted from collisions where the cyclists were hit from behind, especially at night, after investigating Australian bicycle/motor vehicle crashes. In addition, Bil, Bílováa, & Müller, (2010) found that the highest percentages of cyclists’ fatalities occurred on straight road segments (23%) and curved road segments (16%) after analyzing patterns found in 5428 cyclists/motor vehicle collisions in the Czech Republic.
Bicycle taillights have been found to enhance nighttime conspicuity (for a review, see Kwan & Mapstone, 2004). However, there are several gaps in the relevant literature, such as whether there is an optimal taillight mode, such as flashing or steady, and an optimal place to mount a taillight for enhancing a cyclist’s nighttime conspicuity. Although Wood et al. (2012) found no significant difference between the recognition distances of flashing and steady headlight, this comparison has never been studied empirically using bicycle taillights (which are red and less intense than headlights). With regard to taillight placement, studies have consistently found that placing lights or retroreflective material on major joints (e.g., knees, and ankles) can enhance bicyclist conspicuity (e.g., Blomberg, Hale, & Preusser, 1986; Koo & Dunne, 2012; Koo & Huang 2015; Stapleton, Stapleton, Koo, & Koo, 2017; Tyrrell, Fekety, & Edewaard, 2016; Wood et al., 2012). Indeed, there is a growing body of literature that supports the concept of biological motion (“biomotion”; Johansson, 1973); humans’ perceptual sensitivity to discriminating human joint movement patterns (for a review, see Tyrrell, Wood, Owens, Whetsel Borzendowski, and Stafford Sewall, 2016). What remains unclear is whether the bicyclist needs to be physically pedaling in order for biomotion to be perceived. Balk, Tyrrell, Brooks, and Carpenter (2008) found that pedestrians who walked in place elicited longer participant response distances than pedestrians who stood still. While this provided empirical support that biomotion configurations offer more benefits for pedestrians when their extremities are in motion, the parallel comparison for bicyclists (i.e., non-pedaling cyclist vs. pedaling cyclist) has never been made. The present study examined the conspicuity values of four taillight configurations that were systematically varied in terms of taillight mode (flashing or steady) and placement (seat post or heel) on two distinct roadway geometries.
Methods. Visually healthy participants (N = 219) were driven along a designated test route and were asked to press a button on a numeric keypad each time they became confident that a bicyclist was present. Participants encountered Cyclist 1 (who was positioned adjacent to a straight road) approximately five minutes into the drive, and approximately two minutes later, participants were driven past Cyclist 2 (who was positioned after a 90 degree curve). Upon each press of the response button, a timer on the computer was activated. The researcher stopped the timer upon passing each relevant cyclist. The time between the participants recognizing a cyclist and the vehicle passing the cyclist was used to calculate each participant’s response distance (Distance = Speed * Time). This technique has been used in numerous on-road pedestrian studies, and its accuracy has been verified (e.g., Fekety, Edewaard, Stafford-Sewall, & Tyrrell, 2016; Whetsel- Borzendowski, Stafford-Sewall, Rosopa, & Tyrrell, 2015). After passing both test cyclists, the participants were informed that the experimental session was finished, and they were then debriefed while they were driven back to campus where they were released. Each experimental session lasted approximately 30 minutes. Response distances resulting from trials where glare from oncoming vehicles interfered with the participants’ view of the bicyclists were excluded from the analyses. A response distance of 0 m was recorded whenever a participant failed to respond or responded after passing a cyclist.
Results. Two separate between-subjects analysis of variance (ANOVA) tests were performed to examine each of the four taillight configurations’ distributions for Cyclist 1 and Cyclist 2.
For Cyclist 1, the main effect of Taillight Configuration was statistically significant, F(3,168) = 19.21, η2 = .255, p < .001. Bonferroni post-hoc pairwise comparisons revealed that, when steady lights were mounted to the cyclist’s pedaling heels, participants responded from a mean distance that was 1.7 times greater than when a flashing light was mounted to the seat post and 5.5 times than when a steady light was mounted to the seat post or when lights were mounted to the cyclist’s non-pedaling heels. In addition, the mean response distance for the flashing seat post configuration was 3.1 times greater than those for the steady seat post configuration and the non-pedaling heel-mounted lights.
For Cyclist 2, the main effect of Taillight Configuration was also statistically significant, F(3,162) = 9.82, η2 = .154, p < .001. Bonferroni post-hoc pairwise comparisons indicated that when either a flashing or steady light was mounted to the seat post or the lights mounted to the cyclist’s pedaling heels the mean response distances were 1.6x greater than the mean response distance for the non-pedaling heel-mounted lights configuration.
Discussion. This study investigates the use of bicycle taillights as a way for bicyclists to help approaching drivers to more quickly recognize their presence on roadways of differing geometries at night. The results of this study suggest that, in order to maximize conspicuity while riding at night, it seems best to use two heel-mounted taillights. This configuration capitalizes on drivers’ perceptual sensitivity to the biological motion of other people. However, cyclists with only one taillight should use it on a flashing setting while mounted to their bicycle’s seat post when riding at night in order to enhance their conspicuity to approaching drivers. Bicyclists must also be informed that conspicuity aids are not effective 100% of the time, and therefore, they should always ride defensively. Still, this study empirically demonstrated that highlighting a bicyclist’s movement with lights is effective for maximizing nighttime conspicuity. The results of this study can be useful to designers of bicycle taillights, since these data offer valuable insights into how taillights can be used to maximize bicyclist conspicuity at night.
For safety purposes, it is critical that bicyclists be conspicuous to drivers. We report two experiments that investigated the benefits of bicycle taillights and fluorescent clothing for enhancing the bicyclist’s rear conspicuity in daylight. In Experiment 1, 24 participants sat in a car parked on a closed road at each of three distances and rated the conspicuity of four bicyclists displaying taillights that varied in their placement, intensity, and mode. The results confirmed that bicycle taillights can significantly enhance conspicuity in daylight. Varying the placement of the taillights revealed that having an “always on” taillight mounted to each of the rider’s ankles was the most conspicuous location to mount taillights, and this effect was particularly strong at greater viewing distances. For seat post-mounted taillights, flashing taillights were rated as more conspicuous. In Experiment 2, 186 participants were passengers on a short drive during which they pressed a button each time they recognized that a bicyclist was present. Each participant passed a test bicyclist wearing one of four clothing configurations. When the cyclist wore a fluorescent yellow jersey paired with fluorescent yellow leg covers, participants responded from a distance that was 3.3 times greater than when the cyclist wore the same jersey without the yellow leg covers. Both of these experiments demonstrate that highlighting bicyclists’ pedaling motion enhances their conspicuity when viewed from behind. These results further emphasize the conspicuity benefits of biological motion and provide bicyclists with techniques to enhance their own conspicuity in daylight.
Cycling with motor vehicle traffic on roadways is inherently risky for bicyclists, and it is important for bicyclists to make themselves conspicuous to drivers. This experiment used a closed-road method to test the daytime conspicuity of rear-facing bike lights. Participants provided subjective ratings of conspicuity from a test vehicle parked at two different distances from a bicyclist pedaling on a stationary bicycle with one of 16 configurations of bike lights. Some configurations featured lights on the bicyclist’s ankles to highlight the bicyclist’s biological motion. The results of this experiment provide a better understanding of the relative conspicuity benefits of bike lights in daylight as a function of light intensity, light placement, and viewing distance. The findings offer useful insights on the optimal intensity and placement of bike lights to enhance their own conspicuity during daylight.
Lumière is a jacket inspired from an automobile's signaling blinkers by allowing bikers to increase their visibility eliminating the need for hand signaling. The jacket was made of 90% silver based particle-free conductive ink for comfort, lightweight, and wearability. The particle free ink allowed infiltration into fabric, resulting in metallization of individual fibers. The jacket pattern is also specially designed after several user-tests.
Purpose
The purpose of this paper is to investigate the effectiveness of biomotion visibility aids for nighttime bicyclists compared to other configurations via 3D eye-tracking technology in a blind between-subjects experiment.
Design/methodology/approach
A total of 40 participants were randomly assigned one of four visibility aid conditions in the form of videos: biomotion (retroreflective knee and ankle bands), non-biomotion (retroreflective vest configuration), pseudo-biomotion (vertical retroreflective stripes on the back of the legs), and control (all-black clothing). Gaze fixations on a screen were measured with a 3D eye-tracking system; coordinate data for each condition were analyzed via one-way ANOVA and Tukey’s post-hoc analyses with supplementary heatmaps. Post-experimental questionnaires addressed participants’ qualitative assessments.
Findings
Significant differences in eye gaze location were found between the four reflective clothing design conditions in X-coordinate values (p<0.01) and Y-coordinate values (p<0.05).
Practical implications
This research has the potential to further inform clothing designers and manufacturers on how to incorporate biomotion to increase bicyclist visibility and safety.
Social implications
This research has the potential to benefit both drivers and nighttime bicyclists through a better understanding of how biomotion can increase visibility and safety.
Originality/value
There is lack of literature addressing the issue of the commonly administered experimental task of recognizing bicyclists and its potential bias on participants’ attention and natural driving state. Eye-tracking has the potential to implicitly determine attention and visibility, devoid of biases to attention. A new retroreflective visibility aid design, pseudo-biomotion, was also introduced in this experiment.
Purpose
– Bicycles are not only an environmentally friendly means of transportation but are also easily accessible exercise equipment for health. Thus the number of bicycles is gradually increasing. The purpose of this paper is to develop a “Smart Enjoy Interact Light (SEIL)” bag utilizing light emitting diode (LED) display and smartphone apps. By transmitting desired information or images with LEDs, a SEIL bag can protect bicyclists, and also allow wearers to communicate with others.
Design/methodology/approach
– A SEIL built-in bag was developed in the form of a backpack to support all outdoor activities. It can show traffic signals using a wireless controller. Features of design are: ordinary fabric for IT devices; thick and stiff canvas fabric for flexible LEDs; a thin and air-permeable mesh for the LED light; a flexible printed circuit board dashboard for absorbing various shocks; a PVC hard case for the LED display devices; UV coating for waterproofing and durability.
Findings
– A SEIL bag for bicyclists can be useful in a variety of outdoor sports and in commercial applications as well, such as advertising or displaying products. The detachable part can be utilized as a hip sack or a pouch.
Originality/value
– A SEIL bag not only protects bicyclists from traffic accidents, but with which they can express information or images in real time. A SEIL bag is interactive fashion item that emphases communication, thus it will contribute to development of smart-wear.
Smart clothes and wearable technology is a relatively novel and emerging area of interdisciplinary research within the fashion, textile, electronics and related industries. This book provides a comprehensive review of the end-user's requirements and the technologies and materials available for the design and production of smart clothing. Part one looks at the design of smart clothing and wearable technology including the emergence of wearable computing, end-user requirements, and the design process from fibre selection to product launch. Part two examines the general requirements for merging of a range of textile structures with technology and communications for wearable technologies. Part three reviews the types of production technologies available for the development of smart clothing, including garment construction and fabric joining, and the final part discusses the application of these new technologies in smart clothing products and their presentation to consumers. Smart clothes and wearable technology is a unique and essential reference source for researchers, designers and engineers developing textiles and clothing products in this cross-disciplinary area. It is also beneficial for those in the healthcare industry and academics researching textiles, fashion and design. Examines this emerging area of textile research including a brief history and industry overview. Assesses the technologies and materials available for the design and production of smart clothing. Summarises requirements for smart textiles from both health and performance perspectives.
Two experiments were conducted in the laboratory to evaluate potential benefits of different retroreflective markings for nighttime pedestrian visibility. Video recordings of a jogger wearing four different markings were made from a vehicle in four different road environments. Subjects viewed composite tapes that included each of the 16 jogger marking/road environment combinations as well as travel with no targets. The task was to step on a pedal immediately upon seeing a jogger, which had no effect on the flow of the video playback. The time between depression of the pedal and the point of "impact" was the major dependent variable. Experiment I showed that performance was better for all retroreflective markings than for the dark control and that it was better with markings of the limbs than of the torso. Experiment 2, which included a secondary video tracking task, showed that performance was better for markings that incorporate biological motion than for a vest or arbitrarily positioned stripes on the limbs. Questionnaire data indicated that 85% of the subjects judged the biological motion markings to be "easiest to see." Also, subjects reported more conservative estimates of nighttime visibility and greater willingness to take personal precautions at night after participating in the experiment.
Visibility limitations make cycling at night particularly dangerous. We previously reported cyclists' perceptions of their own visibility at night and identified clothing configurations that made them feel visible. In this study we sought to determine whether these self-perceptions reflect actual visibility when wearing these clothing configurations. In a closed-road driving environment, cyclists wore black clothing, a fluorescent vest, a reflective vest, or a reflective vest plus ankle and knee reflectors. Drivers recognised more cyclists wearing the reflective vest plus reflectors (90%) than the reflective vest alone (50%), fluorescent vest (15%) or black clothing (2%). Older drivers recognised the cyclists less often than younger drivers (51% vs 27%). The findings suggest that reflective ankle and knee markings are particularly valuable at night, while fluorescent clothing is not. Cyclists wearing fluorescent clothing may be at particular risk if they incorrectly believe themselves to be conspicuous to drivers at night.
Retro-reflective properties of six types and five different colors or retro-reflective materials were discussed in this paper. Reflectance optical indicatrix of samples was determined and compared to obtained psychophyisical data of perceived brightness of human observer. Microscopic structure of the retro-reflective active regions of RR's was studied. Statistically significant differences in reflectivity and brightness of various types and colors of RR's were found.
Using recent accident data to simulate a common collision environment, a 10-minute car journey was filmed in which a moving or stationary pedestrian wearing one of two types of retroreflective clothing appeared in an environment with high visual clutter. It was hypothesized that moving pedestrians would be detected at greater distances when wearing retroreflective aids in biological motion configuration (‘biomotion’ clothing), but not when wearing a standard retroreflective vest. Participants viewed films of the journey, pressed a button when they detected the pedestrian and rated the difficulty of the task. Biomotion clothing did not significantly increase detection distance for either moving or stationary pedestrians compared to the vest. However, moving pedestrians were detected significantly further away than stationary pedestrians with both clothings. The results do not support the hypothesis that biological motion clothing affords recognition at greater distances than standard conspicuity aids in environments with high visual clutter. Copyright © 2002 John Wiley & Sons, Ltd.
The advent of novel materials (such as conductive fibers) combined with accessible embedded computing platforms have made it possible to re-imagine the landscapes of fabric and electronic crafts—extending these landscapes with the creative range of electronic/computational textiles or e- textiles. This paper describes the LilyPad Arduino, a fabric- based construction kit that enables novices to design and build their own soft wearables and other textile artifacts. The kit consists of a microcontroller and an assortment of sensors and actuators in stitch-able packages; these elements can be sewn to cloth substrates and each other with conductive thread to build e-textiles. This paper will introduce the latest version of the kit; reflect on its affordances; present the results of our most recent user studies; and discuss possible directions for future work in the area of personalized e-textile design and its relation to technology education.
Two quasi-experiments investigated the contribution of reduced visibility to fatal accidents recorded by the U.S. Fatal Accident Reporting Systems from 1980 through 1990. Quasi-Experiment 1 evaluated 104,235 accidents that occurred during morning and evening time periods, called Twilight Zones, during which natural illumination varied systematically in conjunction with the annual solar cycle. Fatal accidents were found to be overrepresented during darker portions of the Twilight Zones. This finding was not related to time of day, day of week, or drivers’ consumption of alcohol. The contribution of reduced visibility was also indicated by higher overrepresentation of fatal accidents in low illumination under adverse atmospheric conditions and with pedestrians and pedalcyclists as opposed to all other accidents. Reduced visibility was more important than drivers’ drinking as a contributor to fatal pedestrian and pedalcycle accidents, while the reverse pattern was found for all other fatal traffic accidents. Quasi-Experiment 2 assessed the role of seasonal variables other than natural illumination by comparing the monthly distributions of 337,726 accidents recorded during three time periods: the Twilight Zones plus equal-duration control periods of Daylight and Darkness. The distribution of fatal nonpedestrian accidents exhibited no substantial variation across months in any of the test periods. The incidence of fatal pedestrian/pedalcycle accidents covaried with natural illumination during the Twilight Zones, while showing no variation during Daylight and Nighttime Control periods, confirming that visibility is a key factor in pedestrian and pedal cycle accidents. The present findings provide new evidence for both (1) the importance of visibility as a major contributing factor in fatal pedestrian and pedal cycle accidents, and (2) the relative success of previous efforts to deal with the difficulties of nighttime driving in other classes of fatal accidents. Michigan University, Ann Arbor, Industry Affiliation Program for Human Factors in Transportation Safety http://deepblue.lib.umich.edu/bitstream/2027.42/49541/1/UMTRI-93-33.pdf
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 Safety http://deepblue.lib.umich.edu/bitstream/2027.42/49397/1/UMTRI-99-6.pdf
To investigate age and sex influences on fall characteristics.
A total of 1243 subjects (517 males and 726 females) aged 50 years and over and drawn from population based sampling frames were invited to complete an interviewer administered questionnaire concerning descriptive characteristics of falls experienced in the previous four months. Information collected included details about the part of the body to strike the ground, direction of the fall, level of trauma and whether or not injury or fracture was sustained.
One hundred and seventy two subjects reported a fall in the previous four months. Restricting analysis to the 142 subjects who fell from a standing height or less, females aged 50-64 years were more than twice as likely to fall onto their hand compared with older females (odds ratio (OR) = 2.2; 95% confidence interval (CI) 0.8 to 6.2) and at all ages (50+) were more than three times as likely to fall on their hip compared with males (OR = 3.4; 95% CI 1.0 to 11.5). Compared with older males, males aged 50-64 were more likely to fall sideways (OR = 5.1; 95% CI 1.5 to 17.4) and less likely to fall forwards (OR = 0.4; 95% CI 0.1 to 1.1).
There is a potentially clinically important variation in fall type by age and sex. In particular, this variation might explain patterns of occurrence of hip and Colles' fracture.
This chapter provides an overview of the production technologies used to manufacture nonwovens, the characteristics of the resulting fabrics, their application in smart clothes and wearable technologies and 'end-of-life' considerations. Key web-bonding, web-forming, fabric finishing and product make-up processes are summarised and an overview of the raw materials used in production is given. The use of reclaimed and bio-degradable fibres in nonwoven production and the application of various nonwovens as: support materials; alternatives to traditional outer garment fabrics; performance and art fabrics and; medical and protective clothing fabrics are also discussed.
The perceived brightness and detectability of six colors of commercially available retroreflective materials that had not been photometrically matched is investigated. Sixteen young observers estimated the brightness of six different colors of retroreflective material at each of four distances, and detection distance was assessed as the observer was driven slowly towards a small patch of each color. Variations in retroreflective power accounted for roughly 90% of the variations in perceived brightness and 95% of the variations in detectability. Thus, the large variations in retroreflective power overshadowed any chromatic effects, brightness and detectability were maximized when retroreflective power was maximized.
Most collisions between vehicles and pedestrians occur at night and inadequate visibility has been implicated as a key causal factor. Earlier research has shown positioning reflective markers to depict biological motion greatly enhances pedestrian conspicuity at night. To determine the extent to which enhanced conspicuity can be achieved with fewer biological motion elements, we measured the distance at which passengers pressed a button to indicate their confidence that a pedestrian was present. 120 university students (18–24 years) were driven along a 5.1 mile residential route using low beams. At two dark locations along the route a pedestrian (an experimenter) had been positioned to the right of the roadway. The pedestrians, who either stood still or walked in place, wore either black clothing or black clothing plus 304 cm² of retroreflective material in four different configurations (a rectangular vest; ankles; ankles & wrists; full biological motion). The mean response distance for the vest condition (23.8 m) was not significantly different from the mean response to the black condition (30.6 m). When pedestrians were walking in place, all conditions with markings on the extremities were significantly more conspicuous, with response distances ranging from 88.9 m (ankles) to 113.5 m (biomotion). Although the advantages of marking the extremities was reduced when the pedestrians were standing still, the biological motion configuration (63.2 m) and the ankles & wrists configuration (45.4 m) remained significantly more conspicuous than the other conditions. Marking the ankles only (where low beam illumination is maximal) was effective when the pedestrian was walking but was ineffective when the pedestrian stood still. These results confirm that incorporating biological motion substantially enhances pedestrian conspicuity at night. Interestingly, our results also suggest that motion patterns alone can not explain the conspicuity advantages of biological motion.
Daytime conspicuity of targets with fluorescent and nonfluorescent backgrounds as a function of the peripheral angle and the target size was investigated in the field. The resulting peripheral detection and recognition data may prove relevant to, for example, a bicyclist or a pedestrian approaching a driver at an intersection from a side street, or to a construction worker approaching a driver in a road construction site. Two groups of nine young, healthy subjects were used. White, blue, green, red, fluorescent red, fluorescent yellow-green, yellow, fluorescent yellow, orange, and fluorescent orange were presented at peripheral angles to the right of the line of sight. The targets were presented at a radial distance of 30 m (100 ft) from the front bumper of the car at the selected peripheral angle. The subjects were seated in a stationary car and the targets were visible for 2 sec. Each subject provided a total of 180 observations. The results of this study indicate that the fluorescent color targets (especially the fluorescent yellow-green) were considerably better-detected peripherally than their nonfluorescent counterparts. Furthermore, for some peripheral angles fluorescent yellow-green was among the top three best-recognized colors. On the basis of the results of this study, it may be concluded tentatively that to maximize daytime conspicuity for peripheral detection and recognition, highly conspicuous fluorescent colors such as fluorescent yellow-green, along with a fairly large target size, should be selected. It appears that however conspicuous a color is alone, if the target is too small for the visual angle subtended, the color will not be well detected or recognized, especially at larger peripheral viewing angles.
High-visibility safety clothing serves an important role in protection of personnel in highway construction. A total of 236 fatalities in highway and street construction were reported for 1992-1993 by the Laborers' Health and Safety Fund of North America, which puts the fatality rate of private-industry highway construction at twice that of other private-industry construction. A field study was conducted to determine the most conspicuous color of safety clothing for daytime use in the work zone. The 11 colors studied included 8 fluorescent (F1) colors (green, yellow-green, yellow, yellow-orange, red-orange, a combination of red-orange with yellow-green, red mesh over white background, and pink), two nonfluorescent colors (yellow and orange), and one semifluorescent color (yellow). Subjects were required to look through a shutter, which opened for 300 msec at 30.5-m intervals, as the researcher drove 32 km/hr toward a work zone. Subjects were instructed to indicate the point at which they first identified safety clothing in the scene. These detection distances were recorded for each color in each of four work zones. Fl red-orange was found to have the highest mean detection distance, and it was significantly different from every color except the F1 red mesh, F1 yellow-green, and F1 red-orange/F1 yellow-green combination. Each of these colors is recommended for use in safety garments with the exception of F1 red mesh, because the mesh may not perform well if worn over darker clothing.
Conspicuity limitations make bicycling at night dangerous. This experiment quantified bicyclists' estimates of the distance at which approaching drivers would first recognize them. Twenty five participants (including 13 bicyclists who rode at least once per week, and 12 who rode once per month or less) cycled in place on a closed-road circuit at night-time and indicated when they were confident that an approaching driver would first recognize that a bicyclist was present. Participants wore black clothing alone or together with a fluorescent bicycling vest, a fluorescent bicycling vest with additional retroreflective tape, or the fluorescent retroreflective vest plus ankle and knee reflectors in a modified 'biomotion' configuration. The bicycle had a light mounted on the handlebars which was either static, flashing or off. Participants judged that black clothing made them least visible, retroreflective strips on the legs in addition to a retroreflective vest made them most visible and that adding retroreflective materials to a fluorescent vest provides no conspicuity benefits. Flashing bicycle lights were associated with higher conspicuity than static lights. Additionally, occasional bicyclists judged themselves to be more visible than did frequent bicyclists. Overall, bicyclists overestimated their conspicuity compared to previously collected recognition distances and underestimated the conspicuity benefits of retroreflective markings on their ankles and knees. Participants mistakenly judged that a fluorescent vest that did not include retroreflective material would enhance their night-time conspicuity. These findings suggest that bicyclists have dangerous misconceptions concerning the magnitude of the night-time conspicuity problem and the potential value of conspicuity treatments.
Five experiments are reported in which visible distances on the near side of the road were measured in a situation in which two cars meet in the dark :(1)Both ears had full headlights or both had dipped symmetrical headlights. Full headlights were found to give longer visible distances during the whole meeting.(2)The same lighting conditions were compared taking signal reflectance into consideration. The higher the reflectance, the greater the difference.(3)The same lighting conditions were compared in simulated hill mooting situations. Full headlights still gave longer visible distances.(4)Symmetrical and asymmetrical dipped headlights of types common in Sweden were compared. As a source of glare in a meeting situation they were equal, although visible distance was considerably longer with the asymmetrical type.(5)Full headlights and asymmetrical dipped headlights were compared. Full headlights gave longer visible distances.These results indicate that the dipping of headlights, while cutting down the discomfort due to glare when cars meet also shortens the distances visible from the cars concerned.
A field experiment was conducted to determine the extent of conspicuity enhancement provided pedestrians and bicyclists at night by various commercially available retroreflective materials and lights. The conspicuous materials were designed to be worn or carried by the pedestrians and bicyclists. Detection and recognition distances for the various experimental and baseline conditions were determined using subjects driving instrumented vehicles over a predetermined route on a realistic closed-course roadway system. Field experimenters were used to model the conspicuity-enhancing materials employing natural motion associated with walking and bicycling. Comparisons of the detection and recognition distances suggested that pedestrians and bicyclists can greatly enhance their conspicuity to drivers at night by wearing certain types of apparel and by using devices that are currently available in the marketplace. Nevertheless, it was concluded that nighttime pedestrian and bicyclist activity is inherently dangerous, even with these devices, and should be avoided.
Bicycling at night is more dangerous than in the daytime and poor conspicuity is likely to be a contributing factor. The use of reflective markings on a pedestrian's major joints to facilitate the perception of biological motion has been shown to greatly enhance pedestrian conspicuity at night, but few corresponding data exist for bicyclists. Twelve younger and twelve older participants drove around a closed-road circuit at night and indicated when they first recognized a bicyclist who wore black clothing either alone, or together with a reflective bicycling vest, or a vest plus ankle and knee reflectors. The bicyclist pedalled in place on a bicycle that had either a static or flashing light, or no light on the handlebars. Bicyclist clothing significantly affected conspicuity; drivers responded to bicyclists wearing the vest plus ankle and knee reflectors at significantly longer distances than when the bicyclist wore the vest alone or black clothing without a vest. Older drivers responded to bicyclists less often and at shorter distances than younger drivers. The presence of a bicycle light, whether static or flashing, did not enhance the conspicuity of the bicyclist; this may result in bicyclists who use a bicycle light being overconfident of their own conspicuity at night. The implications of our findings are that ankle and knee markings are a simple and very effective approach for enhancing bicyclist conspicuity at night.
Although placing reflective markers on pedestrians' major joints can make pedestrians more conspicuous to drivers at night, it has been suggested that this "biological motion" effect may be reduced when visual clutter is present. We tested whether extraneous points of light affected the ability of 12 younger and 12 older drivers to see pedestrians as they drove on a closed road at night. Pedestrians wore black clothing alone or with retroreflective markings in four different configurations. One pedestrian walked in place and was surrounded by clutter on half of the trials. Another was always surrounded by visual clutter but either walked in place or stood still. Clothing configuration, pedestrian motion, and driver age influenced conspicuity but clutter did not. The results confirm that even in the presence of visual clutter pedestrians wearing biological motion configurations are recognized more often and at greater distances than when they wear a reflective vest.
In this article the author uses projective relations as the theoretical foundation of his investigations of visual space and motion. Several laboratory experiments involving perceptual vector analysis and its geometric basis are described. In most of the experiments the visual stimuli consisted of computer-controlled patterns displayed on a televisionlike screen and projected into the eyes of subjects by means of a collimating device that removed parallax as well as the possibility of seeing the screen. A common characteristics of the experiments was that the observer was evidently not free to choose between a Euclidean interpretation of the changing geometry of the figure in the display and a projective interpretation. For example, the observer could not persuade himself that what he was seeing was simply a square growing larger and smaller in the same visual plane; his visual system insisted on telling him that he was seeing a square of constant size approaching and receding. Hence he perceived rigid motion in depth, rotation in a specific slant, bending in depth and so on, paired with the highest possible degree of object constancy. Further experiments were conducted to determine if the principles of perceptual analysis hold true for the more complex paterns of motions encountered in everyday life. These experiments led to the conclusion that during locomotion the components of the human visual environment are interpreted as rigid structures in relative motion.
This paper examines the fatal bicycle accidents which occurred in the period 1981-1984 in Victoria with particular emphasis on nighttime fatalities. The examination provides information on aspects of accident location, environment, problem type, time, and cyclist characteristics. The relationship between actual accidents and cyclists perceived collision danger is also investigated. The characteristics of fatal bicycle accidents are different to those of overall "casualty" accidents. A difference also exists between day and night, and between metropolitan and nonmetropolitan fatal accidents. In the metropolitan area, adult cyclists over 17 years were over-involved in fatal accidents. The proportion of cyclists involved in fatalities at night increases with increase in age. Almost 80% of nighttime accidents occurred on links on arterial roads, and the majority in the high speed limit zones (75 kph and over). A greater proportion of accidents was initiated by cyclists. In 90% of nighttime cyclist fatalities the cyclist was hit from the rear, compared with 40% in daytime. Inadequacy of bicycle and street lighting was found to be an important factor in nighttime fatalities.
In an earlier experiment the conspicuity of disc targets erected along a route in a suburban district was assessed in two field trials. One of the trials required observers to drive a motor vehicle along the route and to report the objects that attracted their attention when they were unaware of the presence of the disc targets. In the other trial, the observers were directed to locate and report the disc targets together with all road traffic control devices. The frequency of reporting the disc targets was taken as a measure of their conspicuity. In the first trial the measure is termed attention conspicuity since the disc target has to attract attention in order to be noticed; in the second trial the measure is termed search conspicuity, since the observers were directed to search for the targets. In order to test whether the result of these field trials of conspicuity could be predicted by laboratory experiment, several laboratory trials replicating the field trials were conducted using movie film and tachistoscopically projected coloured slides. It is shown that the laboratory studies can predict the relative conspicuity of the different disc targets. The movie film experiment provided a good prediction of the field experiment results and the use of tachistoscopically projected slides taken from a distance of 100 m and projected for 250 ms also afforded a satisfactory prediction. The laboratory experiment involving tachistoscopic projection of slides for 1500 ms provided the least satisfactory prediction.
Several fluorescent and non-fluorescent colours are compared to determine which is to be recommended for safety clothing for people who work on or near the road. It was found in a variety of circumstances that fluorescent orange is advisable. Non-fluorescent yellow was found to be better than fluorescent yellow. White is significantly worse as a safety colour than any of the other alternatives, and should not be used without an additional coloured surface.Not much effect was found from some simple designs (e.g. chevron), nor does it seem necessary to dress a man fully in fluorescent clothing, A 30 cm wide band around the body is sufficient.
We have measured the brightness (luminance) of the light spot produced by 105 Macintosh 3 laryngoscope blades (33 bulb, 72 fibrelight) using a Hagner photometer. An estimate of the minimum luminance required for laryngoscopy (circa. 100 cd.m-2), was determined using a laryngoscope adapted to provide a variable light output. Five (15%) of bulb blades and 24 (33%) of the fibrelight blades failed to meet this minimum level. A new bulb blade produced brighter lighting conditions (maximum 700 cd.m-2) than a new fibrelight blade (max. 500 cd.m-2). In total, 61 (84%) of the fibrelight blades and three (9%) of the bulb blades were found to provide a light spot that encompassed areas of luminance below 30 cd.m-2, which is a level for comfortable reading. The light spot from a mains-powered fibreoptic bronchoscope was found to be four times brighter (2000 cd.m-2) than a new battery-powered fibrelight laryngoscope.
This field study investigated potential effects of retroreflector positioning on recognition of nighttime pedestrians. The subject's task was to press a response button whenever he/she recognized a pedestrian on or alongside the road, while in a car with low-beam lamps on that was driven at a constant speed on a dark road. The results showed that each retroreflector configuration yielded significantly longer recognition distances than the no-retroreflector configuration. More importantly, the retroreflective markings attached to the limbs led to significantly longer (about 60-80%) recognition distances than when the retroreflective markings were attached to the torso. Furthermore, a pedestrian was more recognizable while crossing the road than while approaching the subject vehicle, except for configurations involving no retroreflective markings.
To assess injury prevention measures used by cyclists in Oxford and to detect any differences between wearers and non-wearers of cycling helmets.
A prospective observational survey of a series of cyclists passing a single point on a busy city road in reduced lighting. Two observers jointly recorded four measures of injury prevention: use of front or rear light, high visibility (reflective or fluorescent) clothing, and cycling helmet. The use of the first three interventions was analysed in relation to helmet use/non-use.
A total of 392 cyclists were observed over one hour. Fourteen (3.6%) were observed to use all four studied measures, while 137 (34.9%) used none of them. The frequency of measures observed was: lit front light 190 (48.5%), lit rear light 197 (50.2%), both lights on 163 (41.6%), helmet on 104 (26.5%), and high visibility clothing 39 (9.9%). Despite the helmet using group's smaller size, it contained a significantly higher proportion of cyclists with lit front light (60.6% v 44.1%), lit rear light (61.5% v 46.2%), and high visibility clothing (27.9% v 3.5%), than the non-helmet group (p < or = 0.01). Whereas only 22% of the helmet users had no other observed measures, 47.2% of non-users did so.
Cycling helmet users were significantly more likely to use collision prevention measures in conditions of reduced visibility. Explanations may include higher levels of risk awareness and greater knowledge of safe cycling practices in the smaller, helmet using group. However, current measures by cyclists in a major cycling centre may be insufficient to prevent collisions and consequent serious injury or death.
Visibility aids have the potential to increase the visibility of pedestrians and cyclists who use these devices, but their effect on safety is unknown Walking and cycling are promoted for their environmental, economic and health benefits. However, pedestrians and cyclists account for nearly one third of all road traffic deaths. Seeing pedestrians and cyclists too late is one of the most common causes of collisions. Aids, such as reflective garments and flashing lights, in red and yellow colours, aim to enhance visibility and alert drivers in time to avoid collision. The review of trials shows that visibility aids improved drivers' responses in detecting and recognising pedestrians and cyclists. However, no trials were found which studied whether this improves safety for pedestrians and cyclists.
Danish studies of traffic accidents at priority intersections have shown a particular type of accidents. In these accidents a car driver supposed to give way has collided with a bicycle rider on the priority road. Often the involved car drivers have maintained that they did not see the bicycle until immediately before the collision even though the bicycle must have been clearly visible. Similar types of accidents have been the subject of studies elsewhere. In literature they are labelled "looked-but-failed-to-see", because it seems clear that in many cases the car drivers have actually been looking in the direction where the other parties were but have not seen (i.e. perceived the presence of) the other road user. This paper describes two studies approaching this problem. One study is based on 10 self-reported near accidents. It does show that "looked-but-failed-to-see" events do occur, especially for well experienced drivers. The other study based on Gap Acceptance shows that the car driver acceptance of gaps towards cyclists depends on whether or not another car is present. Hypotheses for driver perception and for accident countermeasures are discussed.
This study aims to quantify the effect of visibility aids on the occurrence of pedestrian and cyclist-motor vehicle collisions and injuries, and drivers' responses in detection and recognition. Trial reports were systematically reviewed according to predefined eligibility criteria, including randomised controlled trials or controlled before-and-after trials comparing visibility aids and no visibility aids, and of different visibility aids on pedestrian and cyclist safety, and drivers' responses in detection and recognition. This included trials in which the order of interventions was randomised, or balanced using a Latin square design. Two reviewers independently assessed validity of trials and abstracted data. The main outcome measures were pedestrian and cyclist-motor vehicle collisions and injuries, and drivers'/observers' responses in the detection and recognition time, distance and frequency. No trials which assessed the effect of visibility aids on pedestrian and cyclist-motor vehicle collisions and injuries were identified. Twelve trials examined the effectiveness of daytime visibility aids and 25 trials on night time visibility aids, including 882 participants. Drivers' and observers' detection and recognition improved with visibility aids. For daytime, fluorescent materials in yellow, red and orange colours enhanced detection and recognition. "Biomotion" markings enhanced recognition. Substantial heterogeneity between the trials limits the possibility for meta-analysis. Visibility aids have the potential to improve detection and recognition and would merit further development to gain public acceptance. However, the impact of visibility aids on pedestrian and cyclist safety is unknown and needs to be determined.
Humans, being highly social creatures, rely heavily on the ability to perceive what others are doing and to infer from gestures and expressions what others may be intending to do. These perceptual skills are easily mastered by most, but not all, people, in large part because human action readily communicates intentions and feelings. In recent years, remarkable advances have been made in our understanding of the visual, motoric, and affective influences on perception of human action, as well as in the elucidation of the neural concomitants of perception of human action. This article reviews those advances and, where possible, draws links among those findings.
Background:
Pedestrians and cyclists account for nearly one in three of all road users killed and seriously injured in road traffic crashes. Late detection of other road users is one of the basic driver failures responsible for collisions. Aids to improve pedestrians and cyclist visibility have been used to avert potential collisions. However, the impact of these strategies on drivers' responses, and on pedestrian and cyclist safety is not known.
Objectives:
1. To quantify the effect of visibility aids versus no visibility aids, and of different visibility aids on the occurrence of pedestrian and cyclist-motor vehicle collisions and injuries. 2. To quantify the effect of visibility aids versus no visibility aids, and of different visibility aids on drivers' detection and recognition responses.
Search strategy:
We searched the CENTRAL, the Cochrane Injuries Group specialised register, MEDLINE, TRANSPORT, National Research Register, PsycInfo and PsycLit. We searched the reference lists of included trials, contacted authors and searched the websites of relevant transport research organisations. The searches were last updated in April 2005.
Selection criteria:
1. Randomised controlled trials and controlled before-and-after studies of the effect of visibility aids on the occurrence of pedestrian and cyclist-motor collisions and injuries. 2. Randomised controlled trials of the effect of visibility aids on drivers' detection and recognition responses. This included trials where the order of presentation of visibility aids was randomised or balanced using a Latin square design.
Data collection and analysis:
Two authors independently screened records, extracted data and assessed trial quality.
Main results:
We found no trials assessing the effect of visibility aids on pedestrian and cyclist-motor vehicle collisions and injuries. We identified 39 trials assessing the effect of visibility aids on drivers' responses. Fluorescent materials in yellow, red and orange colours improve detection and recognition in the daytime. For night-time visibility, lamps, flashing lights and retroreflective materials in red and yellow colours increase detection and recognition. Retroreflective materials arranged in a 'biomotion' configuration also enhance recognition. Substantial heterogeneity between and within the trials limited the possibility for meta-analysis. Summary statistics and descriptive summaries of the outcomes were presented for individual trials when appropriate.
Authors' conclusions:
Visibility aids have the potential to increase visibility and enable drivers to detect pedestrians and cyclists earlier. Public acceptability of these strategies would merit further development. However, the effect of visibility aids on pedestrian and cyclist safety remains unknown. Studies which collect data on simple, meaningful outcomes are required.
Interventions for increasing pedestrian and cyclist conspicuity for the prevention of death and injures (review)
- L Kwan
- J Mapstone
Biological motion and pedestrian safety in night traffic
- D A Owens
- R J Antonoff
Color and shape recognition of reflectorized targets under automobile low-beam illumination at night”
- H T Zwahlen
- J Yu
Your guide to the best front lights for cycling and beam comparison engine
- D Atkinson
Modes less traveled-bicycling and walking to work in the United States
- U S Bureau
Evaluation of conspicuity aids for pedal cyclists
- G R Watts