Development and enhancement of road lighting principles

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Aalto-yliopiston teknillinen korkeakoulu | Doctoral thesis (article-based)
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Teknillinen korkeakoulu, elektroniikan laitos, valaistus, 56
The work starts with a short introduction concerning the history of road lighting, outlining the trends and changes that have taken place in road lighting research during the past century. The introduction is followed by a review of trends, directions, and problems in current road lighting research and practice. The following part of the work introduces an advanced approach to road lighting measurements and calculations, based on the use of an imaging luminance photometer and the Road LumiMeter v2.0 computer program. The work sets out to investigate the variations in the characteristics of the quality of the road lighting at the same pilot locations in relation to the calculation methods used. In the work mesopic visual performance and the effects of the spectral transmittance of the vehicle windshield on the visibility conditions of the driver are also analysed. The work continues with road lighting measurements in various weather conditions in order to study the effects of snowy and wet road surface conditions on road lighting luminances. The results show that in Finland, snowy conditions offer very good opportunities to save electricity without adversely affecting either the safety of driving or the quality of road lighting. The following measurements set out to investigate the contribution of halogen and high-intensity discharge headlights to road lighting and whether this has a conflicting effect on the luminance contrasts of various targets located on the road or at the side of the road. The results indicate that, in general, the use of vehicle headlights in the presence of road lighting reduces the luminance contrasts of targets. The work continues with road lighting visibility experiments which study the visibility of achromatic and coloured targets in MH lamp and HPS lamp installations. The results show that colours have a major effect on target visibility if the road is illuminated with a light source with adequate colour rendering properties. Finally, pavement sample measurements are made to study the effects of aggregate lightness and aggregate colour on the reflectance properties of pavements. HPS lamps are found to be more effective than MH lamps in terms of light reflected from pavements.
Supervising professor
Halonen, Liisa, Prof.
Thesis advisor
Eloholma, Marjukka, Dr.
road lighting, measurements and calculations, imaging luminance photometer, weather conditions, vehicle headlights, colour contrast, pavement materials
Other note
  • [Publication 1]: Aleksanteri Ekrias, Marjukka Eloholma, and Liisa Halonen. 2008. An advanced approach to road lighting design, measurements and calculations. Espoo, Finland: Helsinki University of Technology. 51 pages. Helsinki University of Technology, Department of Electronics, Lighting Unit, Report 53. ISBN 978-951-22-9661-3. © 2008 by authors.
  • [Publication 2]: Aleksanteri Ekrias, Marjukka Eloholma, Liisa Halonen, Xian-Jie Song, Xin Zhang, and Yan Wen. 2008. Road lighting and headlights: Luminance measurements and automobile lighting simulations. Building and Environment, volume 43, number 4, pages 530-536. © 2007 Elsevier Science. By permission.
  • [Publication 3]: Aleksanteri Ekrias, Marjukka Eloholma, and Liisa Halonen. 2007. Analysis of road lighting quantity and quality in varying weather conditions. LEUKOS, The Journal of the Illuminating Engineering Society of North America, volume 4, number 2, pages 89-98. © 2007 Illuminating Engineering Society of North America (IES). By permission.
  • [Publication 4]: Aleksanteri Ekrias, Liping Guo, Marjukka Eloholma, and Liisa Halonen. 2008. Intelligent road lighting control in varying weather conditions. Light & Engineering, volume 16, number 1, pages 72-78. © 2008 Znack Publishing House. By permission.
  • [Publication 5]: A. Ekrias, M. Eloholma, and L. Halonen. 2008. The contribution of vehicle headlights to visibility of targets in road lighting environments. International Review of Electrical Engineering (I.R.E.E.), volume 3, number 1, pages 208-217. © 2008 Praise Worthy Prize. By permission.
  • [Publication 6]: Aleksanteri Ekrias, Marjukka Eloholma, and Liisa Halonen. 2008. Effects of vehicle headlights on target contrast in road lighting environments. Journal of Light & Visual Environment, volume 32, number 3, pages 302-314. © 2008 The Illuminating Engineering Institute of Japan. By permission.
  • [Publication 7]: Aleksanteri Ekrias, Marjukka Eloholma, and Liisa Halonen. 2009. The effects of colour contrast and pavement aggregate type on road lighting performance. Light & Engineering, volume 17, number 3, pages 76-91. © 2009 Znack Publishing House. By permission.
  • [Publication 8]: Aleksanteri Ekrias, Anne-Mari Ylinen, Marjukka Eloholma, and Liisa Halonen. 2008. Effects of pavement lightness and colour on road lighting performance. In: Proceedings of the CIE International Symposium on Road Surface Photometric Characteristics: Measurement Systems and Results. Torino, Italy. 9-10 July 2008. © 2008 International Commission on Illumination (CIE). By permission.