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Author Flannagan, M.J.; Sivak, M.; Traube, E.C.; Kojima, S. url  doi
openurl 
  Title Effects of Overall Low-Beam Intensity on Seeing Distance in the Presence of Glare Type Journal Article
  Year 2000 Publication Transportation Human Factors Abbreviated Journal Transportation Human Factors  
  Volume 2 Issue 4 Pages 313-330  
  Keywords Public Safety; Vision  
  Abstract (up) Previous studies have demonstrated that current low-beam headlamps do not provide adequate seeing distance for safety. Could this situation be improved by providing more total light from low-beam headlamps, leaving the relative distribution of light unchanged? Although such a proposal is probably not the best practical solution, it is important to consider some of the visual consequences of a general increase in light to analyze the overall problem of low-beam headlighting.

In a nighttime field study we measured seeing distance in the presence of glare as a function of headlamp intensity, always varying the intensity of the seeing light and glare light by the same proportion. Increasing intensity by a factor of about 3.8 increased seeing distance by about 17% for both young and old drivers. This result is consistent with predictions from quantitative vision modeling using veiling luminance to represent the disabling effects of glare. We also collected subjective estimates of discomfort glare and found, as expected, that the higher intensities produced substantially more discomfort.

Our findings suggest that, if objective visual performance is the only criterion, there is no clear upper limit to how intense low-beam headlamps should be. However, there may be a level at which people simply will not tolerate the subjectively discomforting effects of glare, or at which glare indirectly affects objective performance through its effects on subjective comfort. Because subjective discomfort, rather than objective visual performance, may be the limiting consideration for setting maximum glare levels, more research should be done to understand the nature and consequences of discomfort glare, including possible effects of subjective comfort on objective visual behavior.
 
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  Series Volume Series Issue Edition  
  ISSN 1093-9741 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2127  
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Author Svechkina, A.; Trop, T.; Portnov, B.A. url  doi
openurl 
  Title How Much Lighting is Required to Feel Safe When Walking Through the Streets at Night? Type Journal Article
  Year 2020 Publication Sustainability Abbreviated Journal Sustainability  
  Volume 12 Issue 8 Pages 3133  
  Keywords Public Safety; Security  
  Abstract (up) Public space lighting (PSL) is indispensable after the natural dark. However, little is known about how much PSL people actually need to feel sufficiently safe in different real-world urban settings. The present study attempts to answer this question by employing a novel real-time interactive approach, according to which, observers use a specially-designed mobile phone application to assess and report the perceived attributes of street lighting and the feeling of safety (FoS) it generates. To validate the proposed approach, a systematic survey was conducted in three cities in Israel—Tel Aviv-Yafo and Haifa, which lie on the Mediterranean coast, and Be’er Sheba, which lies inland. Additionally, instrumental PSL measurements were performed at the same locations. As the study reveals, the necessary level of illumination required by urban residents to feel safe differs by city and is significantly higher in Be’er Sheba, other factors held equal, in compare to Haifa and Tel Aviv-Yafo. This difference may be attributed to stronger daylight that the residents of the desert city of Be’er Sheba are accustomed to, and, therefore, may prefer stronger nighttime illumination. The difference could also be related to the relatively low socio-economic status and somewhat higher crime rates in the latter city. Findings also show a significant and positive association between FoS and instrumentally measured PSL levels, although this association exhibits diminishing returns. To the best of our knowledge, the present study is the first to use an interactive location- and time-based mobile phone technology, which can potentially provide more accurate and reliable assessments, compared to traditional “pen and paper” survey techniques.  
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  Series Volume Series Issue Edition  
  ISSN 2071-1050 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2884  
Permanent link to this record
 

 
Author Wood, J.M. url  doi
openurl 
  Title Nighttime driving: visual, lighting and visibility challenges Type Journal Article
  Year 2019 Publication Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (Optometrists) Abbreviated Journal Ophthalmic Physiol Opt  
  Volume Issue Pages in press  
  Keywords Review; Public Safety; headlights; nighttime driving; older drivers; pedestrians and cyclists; streetlights; visual performance  
  Abstract (up) PURPOSE: Nighttime driving is dangerous and is one of the most challenging driving situations for most drivers. Fatality rates are higher at night than in the day when adjusted for distances travelled, particularly for crashes involving pedestrians and cyclists. Although there are multiple contributory factors, the low light levels at night are believed to be the major cause of collisions with pedestrians and cyclists at night, most likely due to their reduced visibility. Understanding the visibility problems involved in nighttime driving is thus critical, given the increased risk to road safety. RECENT FINDINGS: This review discusses research that highlights key differences in the nighttime road environment compared to the day and how this affects visual function and driving performance, together with an overview of studies investigating how driver age and visual status affect nighttime driving performance. Research that has focused on the visibility of vulnerable road users at nighttime (pedestrians and cyclists) is also included. SUMMARY: Collectively, the research evidence suggests that visual function is reduced under the mesopic lighting conditions of night driving and that these effects are exacerbated by increasing age and visual impairment. Light and glare from road lighting and headlights have significant impacts on vision and night driving and these effects are likely to change with evolving technologies, such as LED streetlighting and headlights. Research also highlights the importance of the visibility of vulnerable road users at night and the role of retroreflective clothing in the 'biomotion' configuration for improving their conspicuity and hence safety.  
  Address School of Optometry and Vision Science and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0275-5408 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:31875993 Approved no  
  Call Number GFZ @ kyba @ Serial 2803  
Permanent link to this record
 

 
Author Kersavage, K.; Skinner, N.P.; Bullough, J.D.; Garvey, P.M.; Donnell, E.T.; Rea, M.S. url  doi
openurl 
  Title Investigation of flashing and intensity characteristics for vehicle-mounted warning beacons Type Journal Article
  Year 2018 Publication Accident Analysis & Prevention Abbreviated Journal Accident Analysis & Prevention  
  Volume 119 Issue Pages 23-28  
  Keywords Security; Public Safety; Lighting  
  Abstract (up) Reducing the potential for crashes involving front line service workers and passing vehicles is important for increasing worker safety in work zones and similar locations. Flashing yellow warning beacons are often used to protect, delineate, and provide visual information to drivers within and approaching work zones. A nighttime field study using simulated workers, with and without reflective vests, present outside trucks was conducted to evaluate the effects of different warning beacon intensities and flash frequencies. Interactions between intensity and flash frequency were also analyzed. This study determined that intensitiesof 25/2.5 cd and 150/15 cd (peak/trough intensity) provided the farthest detection distances of the simulated worker. Mean detection distances in response to a flash frequency of 1 Hz were not statistically different from those in response to 4 Hz flashing. Simulated workers wearing reflective vests were seen the farthest distances away from the trucks for all combinations of intensity and flash frequency.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0001-4575 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1950  
Permanent link to this record
 

 
Author Hyari, K.H.; Khelifi, A.; Katkhuda, H. url  doi
openurl 
  Title Multiobjective Optimization of Roadway Lighting Projects Type Journal Article
  Year 2016 Publication Journal of Transportation Engineering Abbreviated Journal J. Transp. Eng.  
  Volume Issue Pages 04016024  
  Keywords Lighting; multiobjective optimization; traffic safety; road safety; lighting design; uniformity; genetic algorithm  
  Abstract (up) Roadway lighting systems play a major role in maintaining nighttime traffic safety as they reduce both the number and severity of nighttime traffic accidents. While the design of roadway lighting systems involves multiple objectives, past studies have focused on optimizing only one of the multiple objectives that should be considered. This paper presents a multiobjective optimization model for roadway lighting projects that simultaneously optimizes four design objectives. The incorporated objectives are (1) maximizing the average lighting level on the road surface; (2) maximizing the lighting uniformity along the roadway; (3) minimizing the glare to road users produced by the lighting system; and (4) minimizing the cost of operating the lighting system. The model is designed and developed as a multiobjective genetic algorithm to help decision-makers in their endeavor to provide efficient roadway lighting systems that strike a balance between the four conflicting objectives. The present model considers the following six design variables: type of lighting fixture, mounting height, spacing, fixture offset, fixture’s inclination, and fixture’s rotation angle. An application example is analyzed in this paper to clarify the use of the model and display its significant features in producing better lighting arrangements for roadways.  
  Address Dept. of Civil Engineering, Hashemite Univ., P.O. Box 150459, Zarqa 13115, Jordan; hyari(at)hu.edu.jo  
  Corporate Author Thesis  
  Publisher ASCE Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0733-947X ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 1405  
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