Author(s):
N.E. Walton, N.J. Rowan
Publication Date
August 1969
Abstract
Research Study 2-8-64-75 was initiated by the Texas Transportation Institute to study existing practices in continuous and interchange lighting of highway facilities and to develop improved methods that will reduce glare, improve uniformity of illumination, and offer greater safety to highway users. Studies were conducted to determine the effects of lighting system geometry on illumination, pavement brightness and disability veiling brightness (DVB) produced by various light sources. The lighting systems tested included one-side, median, and staggered lighting systems with 400- and 1000-watt luminaires! The light distribution relationships between these systems is presented. The cutoff type luminaire was also studied and found impractical. Also studied and presented are facts concerning the effects of lighting system geometry on roadside sign visibility. It was found that mounting height definitely has an effect on visibility and legibility of roadway signs. From studies involving the installation of high-mast illumination towers at two interchanges, it was concluded that this was a very effective means of illumination and is superior to conventional systems. Various luminaire support designs were studied, in order to produce a design which would substantially reduce the severity of collisions with luminaire supports. As a result, the slip base design proved feasible for a multi-directional breakaway base for luminaire supports.
Report Number:
75-13F
Link(s):
Document/Product
http://tti.tamu.edu/documents/75-13F.pdf
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