Highlighting human form and motion information enhances the conspicuity of pedestrians at night. Limitations in drivers' ability to recognize pedestrians at night. High visibility safety apparel and nighttime conspicuity of pedestrians in work zones. Effects of age and illumination on night driving: a road test. Comparing explorative saccade and flicker training in hemianopia: a randomized controlled study. Use of prisms for navigation and driving in hemianopic patients. Effect of a walking aid on disability, oxygenation, and breathlessness in patients with chronic airflow limitation. A randomized controlled trial to evaluate the relative efficacy of adding voluntary counseling and testing (VCT) to information dissemination in reducing HIV-related risk behaviors among Hong Kong male cross-border truck drivers.
Exploring how biological motion can make pedestrians more conspicuous to drivers at night, one-hundred-and-twenty participants were driven along an open-road route at night and pressed a button whenever they recognized that a pedestrian was present. A test pedestrian wearing black clothing alone or with 302 cm2 of retroreflective markings in one of four configurations either stood still or walked in place on an unilluminated sidewalk. Participants' response distances were maximal for the full biological-motion configuration and remained surprisingly long when convenient subsets of reflective markers were positioned on the pedestrian's ankles and wrists. When the pedestrian wore a reflective vest, the responses were no better than when he wore no reflective markings. The biological-motion advantage actually results from interacting form-perception and motion-perception mechanisms. These results confirm that basic perceptual phenomena-observers' sensitivity to human form and motion can be harnessed to reduce an important problem of traffic safety. This study quantified drivers' ability to recognize pedestrians at night. Ten young and 10 older participants drove around a closed road circuit and responded when they first recognized a pedestrian. Four pedestrian clothing and two beam conditions were tested. Results demonstrate that driver age, clothing configuration, headlamp beam, and glare all significantly affect performance. Drivers recognized only 5% of pedestrians in the most challenging condition (low beams, black clothing, glare), whereas drivers recognized 100% of the pedestrians who wore retroreflective clothing configured to depict biological motion (no glare). In the absence of glare, mean recognition distances varied from 0.0 m (older drivers, low beam, black clothing) to 220 m (722 feet; younger drivers, high beam, retroreflective biomotion). These data provide new motivation to minimize interactions between vehicular and pedestrian traffic at night and suggest garment designs to maximize pedestrian conspicuity when these interactions are unavoidable. Every year numerous occupational fatalities result from pedestrians being struck by motor vehicles intruding into work zones.
                Attributes of retroreflective personal safety garments on pedestrian conspicuity at night were assessed in a field study. Using instrumented vehicles on a closed track, participants drove through simulated work zones attempting to detect pedestrians located in the work zones.
                Configuration of the retroreflective trim, trim color, placement in the work zone, and driver age significantly affected pedestrian conspicuity. Intensity and the amount of retroreflective trim did not.
                Personal safety garments incorporating retroreflective trim significantly improve pedestrian conspicuity in work zones.
                The results emphasize the importance of retroreflective trim on personal safety garments, particularly if the trim is located on garment sleeves.
                We examine the design attributes that contribute to making a personal safety garment conspicuous. The results have implications regarding preferred garment designs, industry standards, and service life of personal safety garments. This study investigated the effects of drivers' age and low light on speed, lane keeping, and visual recognition of typical roadway stimuli.
                Poor visibility, which is exacerbated by age-related changes in vision, is a leading contributor to fatal nighttime crashes. There is little evidence, however, concerning the extent to which drivers recognize and compensate for their visual limitations at night.
                Young, middle-aged, and elder participants drove on a closed road course in day and night conditions at a "comfortable" speed without speedometer information. During night tests, headlight intensity was varied over a range of 1.5 log units using neutral density filters.
                Average speed and recognition of road signs decreased significantly as functions of increased age and reduced illumination. Recognition of pedestrians at night was significantly enhanced by retroreflective markings of limb joints as compared with markings of the torso, and this benefit was greater for middle-aged and elder drivers. Lane keeping showed nonlinear effects of lighting, which interacted with task conditions and drivers' lateral bias, indicating that older drivers drove more cautiously in low light.
                Consistent with the hypothesis that drivers misjudge their visual abilities at night, participants of all age groups failed to compensate fully for diminished visual recognition abilities in low light, although older drivers behaved more cautiously than the younger groups.
                These findings highlight the importance of educating all road users about the limitations of night vision and provide new evidence that retroreflective markings of the limbs can be of great benefit to pedestrians' safety at night. Patients with homonymous hemianopia are disabled on everyday exploratory activities. We examined whether explorative saccade training (EST), compared with flicker-stimulation training (FT), would selectively improve saccadic behavior on the patients' blind side and benefit performance on natural exploratory tasks.
                Twenty-eight hemianopic patients were randomly assigned to distinct groups performing for 6 weeks either EST (a digit-search task) or FT (blind-hemifield stimulation by flickering letters). Outcome variables (response times [RTs] during natural search, number of fixations during natural scene exploration, fixation stability, visual fields, and quality-of-life scores) were collected before, directly after, and 6 weeks after training.
                EST yielded a reduced (post/pre, 47%) digit-search RT for the blind side. Natural search RT decreased (post/pre, 23%) on the blind side but not on the seeing side. After FT, both sides' RT remained unchanged. Only with EST did the number of fixations during natural scene exploration increase toward the blind and decrease on the seeing side (follow-up/pre difference, 238%). Even with the target located on the seeing side, after EST more fixations occurred toward the blind side. The EST group showed decreased (post/pre, 43%) fixation stability and increased (post/pre, 482%) asymmetry of fixations toward the blind side. Visual field size remained constant after both treatments. EST patients reported improvements in social domain.
                Explorative saccade training selectively improves saccadic behavior, natural search, and scene exploration on the blind side. Flicker-stimulation training does not improve saccadic behavior or visual fields. The findings show substantial benefits of compensatory exploration training, including subjective improvements in mastering daily-life activities, in a randomized controlled trial. (1) To compare the outcomes of orientation and mobility and driving training with Fresnel prisms and the Gottlieb Visual Field Awareness System for patients with homonymous hemianopsia, and (2) To determine whether the patients continue to use the optical enhancement devices at a 2-year follow-up point.
                Patients with homonymous hemianopsia were provided with a rehabilitation program where they were fitted with prism lenses and trained to use them for navigation and driving. Telephone interviews were used to obtain information about device usage 2 years following the completion of the training program.
                Patients' performance was compared with a test-retest criterion in the visual skills areas of recognition, mobility, peripheral detection, scanning, tracking, and visual memory. Patients with hemianopic loss showed improvements in all of the visual skills categories, ranging from the highest improvements of 26% of tasks improved in the mobility category to 13% in the recognition category. The majority of the hemianopic patients reported using the devices at the 2-year follow-up interview.
                The patients with homonymous hemianopsia showed improvements in visual functioning using prism lenses, although these improvements were smaller than those found in previous studies with central or bilateral peripheral vision loss groups who were trained to use other optical enhancement devices for navigation and driving using a similar curriculum. However, given the evidence of increased risk of accidents for patients with peripheral vision loss, the safety of peripheral enhancement devices for driving must be thoroughly evaluated before their impact on public safety is known. This study assessed the effect of a wheeled walking aid on disability, oxygenation, and breathlessness in patients with severe disability secondary to chronic irreversible airflow limitation.
                Eleven subjects with chronic irreversible airflow limitation, mean forced expired volume in 1 second (FEV1) 0.71 L +/- .33 L, were studied. Subjects performed four 6-minute walk tests, two on each of two study days, twice unaided and twice with the assistance of a wheeled walking aid. A randomized cross-over design was used. All subjects were oriented to 6-minute walk tests, use of bronchodilators was controlled, and standard encouragement was given during each walk test. Outcome measures were the distance walked in 6 minutes, change in oxyhemoglobin saturation during the walk, and breathlessness using a modified Borg Scale.
                The use of a wheeled walker resulted in a significant increase in 6-minute walking distance, a significant reduction in hypoxemia with walking and a significant reduction in breathlessness during the walk test.
                The use of a wheeled walker resulted in significant decreases in disability, hypoxemia, and breathlessness during a 6-minute walk test. By reducing disability and breathlessness, a wheeled walker may improve quality of life in individuals with severe impairment in lung function. Mobile populations are vulnerable to contracting HIV. The present study aims to evaluate the relative efficacy of the voluntary counseling and testing plus information dissemination (VCT-ID) approach versus the information dissemination (ID) approach for promoting HIV preventive behaviors in a mobile population, cross-border truck drivers. A total of 301 adult male cross-border truck drivers who self-reported having had sex with female sex workers (FSW) or non-regular sex partners (NRPs) in mainland China in the last 12 months were recruited and randomized into the VCT-ID intervention group (Group I) or ID control group (Group C). Anonymous structured questionnaires, administered through a computer-assisted method, were used to collect data. At the follow-up survey (about 8-9 weeks since the baseline survey), Group I participants, as compared to Group C participants, were more likely to be consistent condom users when having sex with FSW (85.5% versus 68.5%, p<0.05) and with NRP (54.8% versus 36.4%, p<0.1), more knowledgeable about HIV, and were less likely to have contracted sexually transmitted diseases (STD) in the last two months. The VCT-ID approach is shown to be more efficacious than the ID approach in promoting safer sex and HIV-related knowledge among local cross-border truck drivers. Feasibility of providing voluntary counseling and testing (VCT) services at locations which are convenient to the target population is demonstrated. It also shows that VCT services can be used as a means of HIV prevention. The findings of this study resulted in up-scaled VCT services for the local target population.
Visibility aids have the potential to increase visibility and enable drivers to detect pedestrians and cyclists earlier. Biomotion markings, which highlight the movement and form of the pedestrian, showed evidence of improving pedestrians' conspicuity at night. Public acceptability of various effective strategies which improve visibility would merit further development. However, the effect of visibility aids on pedestrian and cyclist safety remains unknown. A cluster randomised controlled trial involving large communities may provide an answer to this question. It would, however, be a challenging trial to conduct. Studies that collect data of road traffic injuries relating to the use of visibility aids also warrant consideration.