The Evaluation of the Lighting at the Entrance of Very Long Tunnels

Ahmad Mehri; Javad Sajedifar; Milad Abbasi; Mohammad Ali Tajbakhsh; Farough Mohammadian; Tahmineh salehian; Seyed Abolfazl  Zakerian

doi:10.18502/aoh.v5i2.6193

Ahmad Mehri Department of occupational hygiene, School of Public Health, Hamadan university of medical sciences, Hamadan, Iran
Javad Sajedifar Department of Occupational Health Engineering, School of Public Health, Neyshabur University of Medical Sciences, Neyshabur, Iran
Milad Abbasi Social Determinates of Health Research Center, Saveh University of Medical Sciences, Saveh, Iran
Mohammad Ali Tajbakhsh Department of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Farough Mohammadian Assistant Professor, Department of Occupational Health and Safety Engineering, Environmental Health Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran
Tahmineh salehian Department of Nursing & Midwifery,iranshahr University of Medical sciences,iranshahr,iran
Seyed Abolfazl Zakerian Department of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/aoh.v5i2.6193

Keywords: Dark Hole Phenomenon; Luminance; Road Tunnels; De Boer Mental Scale; Safe rate of lighting

Abstract

Background: One of the major topics related to the very long tunnels is dark hole effect. This is a common phenomenon caused by the sunlight reflected from the surroundings of the tunnel to the eyes of drivers and the lack of sufficient light at the tunnels' entrance, which decreases the contrast of barriers inside the tunnel and also makes it difficult to see potential obstacles at the entrance. The result is an increased risk of traffic accidents in these tunnels. Therefore, the aim of this research is to subjectively assessment the safe rate of lighting in one of the very long tunnels located in the province of Ilam.

Methods: To subject evaluation the safe rate of lighting at the tunnel entrances, two parameters of the average luminance of tunnel entrance and equivalent luminance are required. In this study, Luminancemeter device model S3 was used to measure the average luminance of tunnel entrance. Then, to calculate the equivalent luminance, a YASHICA108 camera with a 35 mm lens was photographed at a distance between the tunnel entrance and a safe stopping point, and then the Holliday polar diagram was used to calculate equivalent luminance (accordance with the standard CIE88-2004).

Results: In this study, the average luminance at tunnel's entrance was equal to 17 , the luminance was equal to 127.5 Using the ADRENAL equation, the quality of lightening at the tunnel entrance was less than 1.

Conclusion: Comparison of the results obtained from the healthy and safety rate of lighting levels at the tunnel's entrance with the De Boer mental scale indicated that a dark hole effect occurs at the entrance of the tunnel under investigation and the light sources installed at the entrance of this tunnel did not have the sufficient ability to inhibit the dark hole effect.