title: Survey of discomfort glare from the headlamps of cars widely used in Iran.
abstract: On 2-lane roads, discomfort glare can cause annoyance, discomfort, inconvenience, stress, and fatigue to drivers, posing a risk of accidents. The aim of this study is to evaluate discomfort glare from the headlamps of cars widely used in Iran.
  
  
  
  The discomfort glare of new vehicles including Pride Saba model GTX, Pride Model 131SL, Samand Soren, Peugeot 405, Megane, and Peugeot Pars was examined at distances of 5 to 100 m at a background luminance of 50 cd/m2(late twilight/early dawn lighting) and 1 cd/m2(nighttime) using Schmidt-Clausen and Bindels model and de Boer's subjective scale.
  
  
  
  According to the de Boer scale, at a background luminance of 50 cd/m2, the discomfort glare for all studied vehicles was between 1.98 and 4.05 in high-beam mode and between 3.5 and 5.4 in low-beam mode. At a background luminance of 1 cd/m2, discomfort glare was between 0.41 and 2.48 in high-beam mode and between 1.93 and 3.84 in low-beam mode. In high-beam mode, the average levels of discomfort glare of these vehicles gradually increased when the distance between cars was reduced by up to about 20 m. In low-beam mode, there was no discomfort glare up to a vehicle distance of 40 m. In addition, at an angle of 1.15°-5.73° between the line of sight and light of vehicles in high-beam mode, the level of discomfort glare was increased, but at an angle of 5.73°-22.9° the level of discomfort glare was reduced. In low-beam mode at an angle of 2.86°-22.9°, the level of discomfort glare was almost identical. The results show that in high-beam mode and with a 100-m distance between vehicles as well as in low-beam mode at intervals of less than 40 m between cars, discomfort glare is created.
  
  
  
  It can be concluded that by providing solutions such as installing road lighting system, an increase in luminance of roads, separating or widening road lanes, increasing the lateral distance between vehicles, and increasing the angle between lighted vehicles and drivers can noticeably reduce discomfort glare.
authors.affiliation: a Department of Occupational Health , School of Public Health, Ilam University of Medical Sciences , Ilam , Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Mehri
authors.affiliation: b Department of Occupational Health , School of Public Health, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors.forename: Somayeh
authors.initials: S
authors.lastname: Farhang Dehghan
authors.affiliation: c Work Health Research Center, Qom University of Medical Sciences , Qom , Iran.
authors.forename: Roohalah
authors.initials: R
authors.lastname: Hajizadeh
authors.affiliation: d Department of Occupational Health , School of Public Health, Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Seyed Abolfazl
authors.initials: SA
authors.lastname: Zakerian
authors.affiliation: d Department of Occupational Health , School of Public Health, Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Hamzeh
authors.initials: H
authors.lastname: Mohammadi
authors.affiliation: e Research Center for Environmental Determinants of Health (RCEDH) , Kermanshah University of Medical Sciences , Kermanshah , Iran.|f Scientific Research Center , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Milad
authors.initials: M
authors.lastname: Abbasi
mesh_terms: D000786:Anger; D001334:Automobile Driving / Q000523:psychology*; D001336:Automobiles / Q000706:statistics & numerical data*; D005221:Fatigue / Q000209:etiology; D019466:Glare / Q000009:adverse effects*; D006801:Humans; D007492:Iran; D008029:Lighting / Q000009:adverse effects*; D013315:Stress, Psychological / Q000209:etiology; D011795:Surveys and Questionnaires
keywords: Discomfort glare; Schmidt-Clausen and Bindels model; de Boer's subjective scale; headlamps; safety