Counter-beam lighting

from Wikipedia, the free encyclopedia
Principle of counter-beam lighting

The counter jet lighting (English: counter-beam lighting) is a Straßenbeleuchtungsart, mainly engaged in road tunnel is used and best visibility of obstacles on the road with minimal provides light energy costs. It means increased safety in road traffic and energy savings. The counter-beam lighting is mostly installed at road tunnel entrances, because there, especially in sunshine and entry speeds of up to 100 km / h, the driver's need to avoid being “blind” (see adaptation ) for the first few seconds. With conventional lighting technology, very high luminance levels with correspondingly high energy costs would have to be provided in these areas in order to make obstacles on the road sufficiently visible.

Principle of counter-beam lighting

The light from the lamps does not shine straight down onto the road, but towards the vehicle. With a carefully chosen angle of inclination and suitable lighting ( street lights ), the driver is not dazzled and the road acts as a mirror, which also scatters the light in the direction of the vehicle. Since the road is a poor mirror (gray surface), the driver is not dazzled , but sees the road as a bright surface. With this inclined incidence of light, an obstacle on the road throws a (dark) shadow against the direction of travel. This shadow and the surface of an obstacle facing away from the light source and therefore less illuminated offers the vehicle driver the view of a black surface on the light road (high contrast ). The black area seen is larger than the obstacle itself, which makes it easier to perceive the danger. In the case of perpendicular incidence of light, brighter, more expensive lamps with significantly higher energy requirements and greater maintenance requirements would have to be used in order to achieve equivalent visibility of obstacles. The counter beam lighting is therefore an environmentally friendly contribution to road safety.

history

The counter-beam lighting goes back to the work of Ing. W. Ernst Freiburghaus (* 1921, Bern, † 2006, Bern), who carried out theoretical and practical work on behalf of Bernische Kraftwerke AG (BKW), Bern, Switzerland, in the early 1960s Installations (underpass Worblaufen, Bern, Switzerland). The theoretical knowledge was continued and published by the Federal Office for Metrology, Bern, Switzerland (without citing the author as the author). On the basis of its developments, BKW applied in a letter dated February 24, 1968 for the inclusion of counter-beam lighting (then called "BKW system with oblique radiation") in the guiding principles for public lighting, Part 2, road tunnels and underpasses, of the Swiss Lighting Commission, what however it was rejected. Various Swiss motorway tunnels have since been equipped with this lighting system (in the 1970s, for example, the Allmend tunnel on the A6, the Leimern and Ruge tunnels on the A8). The system in the Rugentunnel of the A8 was positively assessed in 1980 by the Technical Committee TC 4 of the CIE . Today counter-beam lighting is a natural part of almost all national and international guidelines for tunnel lighting (see standards ) and can be found in countless road tunnels all over the world.

Norms

Backlight lighting is included in the recommendations of the International Commission on Illumination and many countries.

literature

  1. ↑ JB de Boer et al .: Practical methods for measuring and calculating the luminance of road surfaces. Philips Res. Rep., 7, 54, 1951
  2. ↑ JW Huijben: Dutch recommendation tunnel lighting 2003. The draft of the entrance lighting with the contrast method .
  3. ^ E. Freiburghaus: lighting of motorways and express roads. Strasse Verkehr, 59 (8), 468-475, 1973
  4. ^ E. Freiburghaus: Modern solutions in street lighting technology. 1st Congress on Vision and Road Safety, Prévention Routière Internationale, F-91310 Linas-Montlhéry, France, Conference Report, 317-325, 1976
  5. ↑ F. Mäder: Use of special asymmetrical lights (oblique spotlights) to illuminate tunnels. Bull. SEV, 60 (25), 1177-1181, 1969
  6. ↑ CIE 088: 2004 In: techstreet.com , accessed June 27, 2017.
  7. ↑ RABT - Guidelines for the equipment and operation of road tunnels In: FGSV Verlag , accessed on June 27, 2017.
  8. ↑ DIN standards committee for lighting technology (FNL) In: din.de , accessed on June 27, 2017.
  9. ↑ RVS 02/09/41 Lighting In: fsv.at , accessed on June 27, 2017.