Outdoor lighting - Mesopic photometry, adaptation conditions and user preferences in pedestrian way lighting

Loading...
Thumbnail Image
Journal Title
Journal ISSN
Volume Title
School of Electrical Engineering | Doctoral thesis (article-based) | Defence date: 2014-06-27
Checking the digitized thesis and permission for publishing
Instructions for the author
Date
2014
Major/Subject
Mcode
Degree programme
Language
en
Pages
68 + app. 56
Series
Aalto University publication series DOCTORAL DISSERTATIONS, 85/2014
Abstract
The starting point of this work is to review the current recommendations and criteria of road and pedestrian way lighting. At present, the emphasis of traffic safety, the increasing energy costs, and improvements in mesopic photometry have led to new discussions about the accuracy of the recommendations for road lighting. Sufficient road lighting is generally based on the lighting requirements given in different lighting classes. For road lighting, the value of 2 cd/m2 is recommended as the minimum average road surface luminance for the highest lighting class in the CIE and CEN publications. The basis of the average road surface luminance for the lower lighting classes is unknown and lacks experimental works. Moreover, the experimental set-ups of the studies conducted in the 1930s and 1950s do not meet the conditions of motor traffic lighting nowadays. They also have deficiencies in the number and age distributions of the subjects. The values of the average horizontal illuminances of the pedestrian way lighting recommendations are based on studies conducted in the 1970s and 1980s. However, no information exists on how the recommended illuminance values are derived for the different lighting classes. The current recommendations for outdoor lighting are based on photopic photometry, this is daylight visibility conditions. In outdoor lighting, the luminances are in the mesopic range. The CIE recommended system for mesopic photometry should be used in providing recommendations and criteria for both road and pedestrian way lighting. Before implementing mesopic photometry, the adaptation luminance of the road users should be known. This study examined the adaptation conditions of pedestrians based on eye-tracking measurements. A case study in a pedestrian way was conducted in Chongqing of China. The study is related to the currently ongoing task of the CIE JCT-1 Implementation of CIE 191 System for Mesopic Photometry in Outdoor Lighting, which is to investigate adaptation and viewing conditions and define visual adaptation fields in outdoor lighting. The case study consisted of eye-tracking measurements and subjective evaluations of the lighting conditions. It was found that the eye-fixation areas and locations were around a central area of the road surface in the horizontal level but spread over a wider area in the vertical level. The subjective importance of facial recognition depends on the specific visual tasks at different light levels in a pedestrian way. The results also suggest that further studies using an eye-tracking system could combine eye-fixation data with pupil size and luminance data. This would help in further analysis of visual adaptation fields of the road users.
Description
Supervising professor
Halonen, Liisa, Prof., Aalto University, Department of Electrical Engineering and Automation, Finland
Thesis advisor
Puolakka, Marjukka, Dr., Aalto University, Department of Electrical Engineering and Automation, Finland
Keywords
lighting criteria, road lighting, pedestrian way lighting, system of mesopic system, visual adaptation field, eye-tracking system
Other note
Parts
  • [Publication 1]: Luo, Wei; Puolakka, Marjukka; Viikari, Meri; Kufeoglu, Sinan; Ylinen, Anne; Halonen, Liisa. 2012. Lighting criteria for road lighting: a review. Light& Engineering, vol.20, No.4, pp.64-74.
  • [Publication 2]: Luo, Wei; Puolakka, Marjukka; Halonen, Liisa. 2012. Mesopic photometry: The CIE 191 system based on visual performance. China Illuminating Engineering Journal, vol.7, No.1, pp.11-14.
  • [Publication 3]: Luo, Wei; Puolakka, Marjukka; Halonen, Liisa. 2012. Outdoor lighting- considerations of mesopic photometry and light source SPD, China Illuminating Engineering Journal, vol.7, No.1, pp.29-32.
  • [Publication 4]: Puolakka, Marjukka; Cengiz, Can; Luo, Wei; Halonen, Liisa. 2012. Implementation of CIE 191 mesopic photometry-ongoing and future actions, In: Proceedings of CIE 2012 Lighting Quality & Energy Efficiency, Hangzhou, China, pp.64-70.
  • [Publication 5]: Luo, Wei; Puolakka, Marjukka; Zhang, Qingwen; Yang, Chunyu; Halonen, Liisa. 2013. Pedestrian way lighting: user preferences and eye-fixation measurements, Journal of Lighting Engineering, vol.15, No.1, pp.19-34.
Citation