1、t; Light Trespass: Research, Results and Recommendations Publication of this Technical Memorandum has been approved by the IESNA. Suggestions for revisions should be directed to the IESNA. Prepared by The Obtrusive Light Subcommittee of the IESNA Roadway Lighting Committee IESNA TM-11=2000 IESNA Tec
2、hnical Memorandum on Light Trespass: Research, Results and Recommendations Publication of this Technical Memorandum has been approved by the IESNA. Suggestions for revisions should be directed to the IESNA. e Prepared by: The Obtrusive Light Subcommittee of the IESNA Roadway iighting Committee Copyr
3、ight 2000 by the Illuminating Engineering Society of North America. Approved by the IESNA Board of Directors, December 2, 2000, as a Transaction of the Illuminating Engineering Society of North America. All rights resewed. No part of this publication may be reproduced in any form, in any electronic
4、retrieval system or otherwise, without prior written permission of the IESNA. Published by the Illuminating Engineering Society of North America, 120 Wall Street, New York, New York 10005. IESNA Standards and Guides are developed through committee consensus and produced by the IESNA Office in New Yo
5、rk. Careful attention is given to styie and accuracy. If any errors are noted in this document, please for- ward them to Rita Harrold, Director Educational and Technical Development, at the above address for verification and correction. The IESNA welcomes and urges feedback and comments. ISBN # 8799
6、5-1 74-5 Printed in the United States of America. I I e Prepared by the Obtrusive Light Subcommittee of the IESNA Roadway Lighting Committee i Obtrusive Light Subcommittee a William A. Hughes, Chair - Bradford, R.A. Canavan, M.G. Chapman, T.J. Cimino, V. Contos, P. Crawford, D.L. Daiber, W. Edmonds,
7、 J.W. Eslinger, G.A. Fairbanks, K. Kosiorek, A.S. Maltezos, M. McCormick, J. McGowan, T.K.* Mickei, J.J. Monahan, D.R. Monsoor, R.G. Morehead, W.E. Oerkvitz, C.A. Okon, D.W. Roadway Lighting Committee John J. Mickel, Chair W. Adrian A.P. Allegretto* B. Ananthanarayanan S.W. Annoh* J.B. Arens J.D. Ar
8、mstrong . J.A. Bastianpillai J. Bodanis P.C. Box R.A. Bradford J.J. Buraczynski* K.A. Burkett J.C. Busser E. Cacique* M.G. Canavan V.F. Carney RA. Catone* T.J. Chapman* B.T. Chau* D. Chaudhuri* A.Cheng* R.B. Chong V. Cimino R.D. Clear P. Contos C.W. Craig D.L. Crawford M.D. Crossiand C.L. Crouch* W.
9、 Daiber J.E. Degnan N. Dittman Z. Durys* G. Duve* W.H. Edman* G.A. Eslinger K. Fairbanks* T. Fenimore* D.H. Fox* M. Freedman* D.G. Garner* R. Gibbons* A.S. Goel* R.C. Gupta R.L. Hamm G. Harlow* J.M. Hart G.A. Hauser* T.S. Hester* W.A. Hughes D.E. Husby* M.S. Janoff J.E. Jeweil* R. Kauffman* M.E. KeW
10、 D. Keith A. Ketvirtis A.S. Kosiorek* J. Kroll* R. LeVere I. Lewin C.H. Loch P.J. Lutkevich D. Mace D.R. Macha M. Maltezos J. McCormick* S.W. McKnight J.F. Meyers C. Miller* D.R. Monahan R.G. Monsoor W.E. Morehead* E. Morel Rowsell, E.C. Schiewe, N.A. Vogel, R.P. Waight, V.H. H.D. Motley“ K. Negash*
11、 H. Odle C.A. Oerkvitz D.W. Okon J.L. Pimenta G.P. Robinson* M.J. Robinson* A.S. Rose E.C. Rowsell PP Sabau N.A. Schiewe R.N. Schwab B.L. Shelby* A.D. Silbiger* J. Simard R.L. Sitzema, Jr. G.E. Smallwood R.E. Stark R. Stemprok* D.C. Strong* J.D. Turner* H.A. Van Dusen R. Vincent R.P Vogel* V. H. Wai
12、ght J.D. Walters C.P. Watson J. Weaver* S. Wegner* A. Williams R.R. Wylie A.B. York* *Advisory Member *Honorary Member Contents Introduction . 1 Background . 1 1.ResearchProject 1 1.SeminarandSurveys 1 2 . Light Sources and Brightness . 1 3.The Experimental Design . 2 4.TestResults . 2 5.AnalysisofR
13、esults . 2 II . Development of Recommendations 6 1 . Area Classifications . 6 2.Curfew 6 3 . Quantitative Recommendations . 7 Summary of Recommendations . 8 Non-curfew Recommendations 8 Exceptions 8 Conclusion 8 References 9 L IESNA TM-1 1-2000 Light Trespass: Research, Results and Recommendations I
14、NTRODUCTION This Technical Memorandum provides a brief descrip- tion of findings and references from a 1998 research project for measuring, determining and identifying light trespass as a component of obtrusive light. Information is included about a specific experiment conducted as part of this rese
15、arch project, which was intended to pro- vide input about how individuals react to light trespass. Recommendations are provided for measuring light trespass and developing guidelines on curfews for spe- cific environmental zones. Also included are references to written material used as a basis for t
16、he research pro- gram. The main body of the research may be found through the Lighting Research mice (LRO).* Since light trespass is a complicated topic, TM-1 1 only begins to address the issues and is limited in its scope. Additional research is welcomed and needed. The information in TM-1 1 is use
17、ful for but not specific to roadway lighting. The results of the research have provided input for two IESNA publications, RP-33, Lighting for Outdoor nvironrnents,2 and TM-1 O, Addressing Obtrusive Light (Urban Sky Glow and Light Pespass) in Conjunction with Roadway Lighting.3 Background One of the
18、most important, ongoing outdoor lighting issues is unwanted light in the night-time environment, which may take numerous forms and result in various concerns. With the increasing awareness of environ- mental issues of all types, it is important that lighting designers recognize the need to provide s
19、olutions for problems related to the general subject of “tight Trespass,” or “Obtrusive Light as it is sometimes called. Numerous local communities, cities, counties, and states have developed ordinances to control unwanted light. These ordinances vary greatly, from simple to complex. They vary also
20、 in the aspects of lighting that they seek to control. There is no coordinated effort to create uniformity among the regulations since no cen- tral authority has developed guidelines to assist in their writing. This problem will be compounded with time as the number and diversity of ordinances incre
21、ases. In the 19803, it became apparent that the control of light trespass and development of meaningful ordi- nances would not be an easy task. “Light trespass,” in * The Lighting Research Institute (LRI) of New York developed a problem statement and awarded a research coniraci io Lighting Caencas,
22、IN., Scottsdaie. Arizona. More detailed coverage about the design of the experiments and the research findings can be found in Me final report published by the Mhting Research office (MO), sucassor to LRI. fact, had not been defined. It was generally accepted that many factors were involved, but the
23、se were not categorized and no numerical information was avail- able to provide the basis for light trespass controls. A program of research was needed to define the para- meters of the problem and produce meaningful infor- mation so that the situation could be addressed. I. RESEARCH PROJECT 1. Semi
24、nar and Surveys A seminar and survey were organized to define the nature of light trespass problems and rank the various sources of light trespass in accordance with their seri- ousness. The following questions were directed to the participants: 1. 2. 3. 4. 5. 6. 7. What constitutes light trespass?
25、Spill light from street lighting? Ball field lighting? Residential lights? Sky glow? Who is affected? What is the nature of the com- plaints? Does light trespass constitute a safety problem or is it primarily aesthetically offensive? What is the visual nature of light trespass? Is the problem the of
26、fensive glare of bright lights, or is it the illumination of areas that are preferred to be dark? Can the problem be defined numerically? What measurable quantities should be considered? How can acceptable levels of light trespass be specified and ordinances developed? What regula- tions are now in
27、effect? Have they been successful? Looking to the future, can a simple meter be devel- oped to check light trespass levels against ordi- nance specifications? The seminar and survey produced much valuable information to more clearly define light trespass. Data were produced which allowed the ranking
28、 of causes of light trespass and the issues on which to focus: 2. Light Sources and Brightness A program was developed to investigate the charac- teristics of light sources, which produce light trespass. Source brightness had been generally identified as being the principal characteristic to which p
29、ersons object. Spill light was seen as a less significant effect. It was decided, therefore, to design experimentation to identify quantitatively the relationship between source brightness and the degree to which the light source was found objectionable. Brightness is a difficult characteristic to i
30、nvestigate. It is the observed effect of the sources physical lumi- 1 IESNA TM-11-2000 i nance, and as such is related to the intensity of the retinal image. This in turn will be affected by charac- teristics of the observers eyes. The measurement of subjective brightness is not practical under the
31、condi- tions of the experimentation, nor could brightness be used to realistically limit the luminaire appearance in a practical ordinance. It is thus logical to base the research on source lumi- nance, that is, physical brightness, rather than observed or subjective brightness. The relationship bet
32、ween source luminance and the subjective bright- ness it produces is affected strongly by the level of ambient lighting. Meaningful research therefore can be conducted to relate source luminance to the observers reaction, if conducted under several differ- ent ambient levels. Recommendations must th
33、en be developed for these different ambient levels, and in doing so, the physical luminance of the source will be a realistic indicator of its subjective brightness. 3.The Experimental Design Observation experiments were planned in which human subjects from a variety of educational and vocational ba
34、ckgrounds would be presented with sev- eral different situations and tasks, in the presence of a test fixture. This test fixture consisted of a controlled source of light of known photometric characteristics. By varying the location, size, and luminance of the test fixture, subjects would determine
35、the degree to which the source was objectionable while conducting the var- actual experiments. Age ranged from 20 to 60 years. Fourteen male and 16 female observers were used. iGus tqrlrr taana. n tulal ui ru uvaci vci a wcic UDGU ii ib A in+ I -4 Qn nh-nm- .- -A * Lighting Conditions and Tasks-Nume
36、rous situations were considered for conducting the experiments. Due to the number of possible permutations of visual task type, ambient lighting and task fixture condition and location, only a few carefully selected conditions could be tested. The selected conditions were: 1. Observers in a room wat
37、ching television. The test fixture was located outside a window to simulate a street light or floodlight. The interior lighting level was low, averaging 5.0 lux (0.5 fc). The distance from the observers to the light source was approx- imately 10m (32 ft.). 2. Observers mingling in an exterior area w
38、ith a low level of ambient lighting of just under 2 lux (0.2 fc). The sources of this light were building perimeter lighting and distant street lighting. The test fixture was located peripheral to the area at a height of 3m (1 O fi.). The distance from the observers to the light source was approxima
39、tely 15 meters (49 fi.) 3. Same condition as condition 2, but with ambient illu- mination increased to approximately 20 lux (2 fc). In the exterior experiments, the test subjects were not instructed to perform any particular task but to judge conditions on the basis of being located on a residen- ti
40、al property. As part of the development of the research program, a pilot study was run. This indicated that the appropri- ate range of interest was from 2000 to 7500 cd/sq.m (1 86 to 697 cdsq. ft.). Accordingly all testing was run between these two limits, in steps of 500 cd/sq.m (46 cdsq. ft.) but
41、in random order. 4.Test Results Results were converted to a numerical measure by assigning the following points to each response: 5 - Extremely objectionable 4 - Very objectionable 3 - Quite objectionable 2 - Slightly objectionable 1 - Not objectionable Points were analyzed for each experimental con
42、dition, both as the average for all observers and individually. For each individual test condition, there was a wide range of ratings assigned by the individual observers, as expected. In general, however, responses showed a range between bceers of 2 io 3 poinis on ihe objectionable scale. It was ra
43、re, for instance, to find one observer judging a test condition to be “slightly objectionable” while another judged the condition to be “extremely objectionable.” In order to handle the spread of results for a given test condition, an average score was calculated using the responses of all observers
44、. This is termed “Objectionable Rating or OR. This rating, in theory, can vary from 1 to 5, although in practice, OR values tended to be concentrated between 2 and 5. Figure 1 presents the results of the indoor testing. Figure 2 presents equivalent data for the outdoor test conducted under low ambie
45、nt conditions, while Figure 3 gives the data and plots for the outdoor test for medium ambient conditions. (Note: In Figures 1,2 and 3, small area is defined as 12 inches square, medium area as 18 inches square and large area as 24 inches square.) 5. Analysis of Results GenerakEach of the three expe
46、riments indicates the same general trends, all of which appear to be logical. L 2 L IESNA TM-11-2000 d 4E 4 8 .t- 3.5 F 0 1.5 O E 5 4.5 4 p: 3.5 O I .- F3 B c 2 2.5 n o E O .= 2 8 a 0 1.5 1 0.5 o Indoor Task O 1000 2000 3Ooo 4Ooo 5ooo 8ooo 7000 8000 Luminance cd/sq.m. Figure 1. Note : Small area = 1
47、2 in. square; medium area = 18 in. square; large area = 24 in. square Outdoor Task - Low Ambient Small Ama A Medium Area O 2000 3000 4000 5000 6000 7000 8000 Luminance cdlsqm. Figure 2. Note : Small area = 12 in. square; medium area = 18 in. square; large area : 24 in. square 3 IESNA TM-1 1-2000 0.5
48、 Figure 3. Note : Small area = 12 in. square; medium area = 18 in. square; large area 24 in. square Close examination of the data reveals significant insight into the relationship between the characteristics of the light source and the degree to which it is objectionable. As a broad summary, the dat
49、a indicate the following: 1. 2. 3. For a given size of test fixture aperture, increasing luminance causes an increase in the OR, under otherwise identical test conditions. For a constant luminance level, increasing the aperture size increases the OR, other factors being constant. The ambient lighting level has a significant effect upon the OR. Distance-Due to the wide number of possible vari- ables in testing of this type, and the enormity of the task of evaluating all possible variables, each test was conducted at a fixed distance between the subjects and tes
