03-27-06 Joint PC-EC Agenda
AGENDA
Golden Valley Planning Commission
Joint Meeting with the Environmental Commission
Lighting Ordinance Discussion
Golden Valley City Hall, 7800 Golden Valley Road
Council Conference Room
Monday, March 27, 2006
6pm
I. Lighting Ordinance Discussion
Golden Valley Planning Commission
Regular Meeting
7pm
I. Approval of minutes
February 27, 2006 Planning Commission Meeting
II. Discussion about creating a Mixed Use land Use Category for the General
land Use Chapter of the Comprehensive Plan
III. Reports on meetings of the Housing and Redevelopment Authority, City
Council, Board of Zoning Appeals and other meetings
IV. Other business
V. Adjournment
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Hey
Planning
763-593-8095 I 763-593-8109 (fax)
Date:
March 27, 2006
To:
Environmental and Planning Commissions
From:
Aaron Hanauer, Planning Intern
Subject:
Outdoor Lighting Ordinance
The third joint Environmental and Planning Commission meeting to discuss a city
outdoor lighting ordinance is scheduled for Monday, March 27 at 6pm. The purpose of
the meeting is to receive feedback from the Environmental and Planning Commission
on the following:
- What is considered good and bad lighting?
- What are your primary concerns with outdoor lighting and having an
outdoor lighting ordinance?
- What do you want addressed in an outdoor lighting ordinance?
This information is important as the city moves forward in adopting an outdoor lighting
ordinance. Reading materials enclosed in this packet summarize the past two joint
meetings as well as provide background information on outdoor lighting. The two main
sources of information were the International Dark-Sky Association and Wikipedia
websites.
It would be helpful if members of the commissions drove around Golden Valley and/or
surrounding communities at night and provide examples of good and bad lighting, by
either describing them at the meeting, bringing pictures with them, or submitting digital
images by Monday afternoon to Aaron Hanauer (ahanauer@cLQolden-vallev.mn.us).
Please call Aaron Hanauer, planning intern, before Monday's meeting with questions.
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Table of Contents
Meeting Summaries..................... ...... ... ........................................................................... 1
What is Light Pollution? ......... ............................ ..................... .... ................. ... ................. 2
Lig hting Issues.................................................................................................................. 2
Lamps, Fixtures, and Lenses Used in Outdoor Lighting............................................ 6
What is an Outdoor Lighting Code? ............................................................................ 11
What Makes a Lighting Code Effective? ................................................................ 11
Should a Lighting Code Limit Pole Height? ........................................................... 13
MEETING SUMMARIES
AUGUST 8, 2005 JOINT EC AND PC MEETING
Grimes stated that there is money in the budget for writing an outdoor lighting
ordinance and the Council sees the need. Hanauer provided research found on
other city outdoor lighting ordinances and provided examples of Bloomington and
Plymouth. Eck noted that there is a lot of technical information in the Plymouth
ordinance and asked if they have someone on staff who can analyze their
development plans to make sure they meet the requirements. Rasmussen stated
that there hasn't seemed to be too many huge concerns about lighting and she
would be interested in knowing what some of the concerns are because she
doesn't want to make it more difficult for people to do developments.
OCTOBER 10, 2005 JOINT EC AND PC MEETING
A joint meeting of the Planning Commission and Environmental Commission.
The purpose of the meeting was to bring in other cities to talk about their
experience with lighting ordinances. The Golden Valley City Code doesn't
address lighting regulations and that the City Council has directed the
Commissions to look at some other cities ordinances and come up with a lighting
code. It was noted that lighting standards for public property can not be adopted,
but a city can have a lighting policy regarding public property lighting. Guests that
were present were Barb Senness, Planning Director for the City of Plymouth,
Londell Pease, Associate Planner for the City of Bloomington and Mark Mlazgar,
owner of R.L. Mlazgar Associates
Plymouth Ordinance
Plymouth used the International Darksky Association model lighting ordinance
(MLO) as their base. Enforcement takes place through connection with the state
inspector for rehab and new development. Plymouth requires developers to submit an
as-built survey to the City as well as the state electrical inspector so they can do enforcement.
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Remodeling projects need to comply when more than 50 percent of site is changed. Hill and .
Baker had concerns about the use of wattage and that there will be brighter light
as light bulbs get more efficient if the watt formula is used which would create the
need to change the ordinance. Another concern is safety, and Senness
mentioned that that their lighting consultant showed their police department a lot
of examples of various properties which really helped them accept their
ordinance
Bloomington Ordinance
Bloomington has had their ordinance in place for 11 years. Developers in their
City can't do anything without a plan review and that they require any fixture
being replaced has to be replaced with a code compliant fixture. They require
that all non-essential lights be turned off one hour after a business closes.
Additional Information
Mark Mlazgar, owner of R.L. Mlazgar Associates stated the lighting ordinances
are really dynamic, not static and need to be frequently reviewed. Two concerns
from the Environmental Commission included the need that a wattage based
ordinance would have to be updated as lights become more efficient and that
cities seem to be reinventing the wheel with lighting ordinances.
WHAT IS LIGHT POLLUTION?
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Light pollution is excess or obtrusive light created by humans. Light pollution can
be construed to have two main branches: (a) annoying light that intrudes on an
otherwise natural.or low light setting and (b) excessive light, generally indoors,
that leads to worker discomfort and adverse health effects. Since the early
1980s, a global dark-sky movement has emerged, with concerned people
campaigning to reduce the amount of light pollution.
Since not everyone is irritated by the same lighting sources, light pollution has a
measure of subjectivity. It is common for one person's light "pollution" to be light
that is desirable for another. Differences in opinion over what light is considered
reasonable, and who should be responsible, means that negotiation must
sometimes take place between parties. Authorities have also taken a variety of
measures for dealing with light pollution, depending on the interests, beliefs and
understandings of the society involved. Measures range from doing nothing at all,
to implementing strict laws and regulations about how lights may be installed and
used.
LIGHTING ISSUES
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There are a number of reasons why lighting is addressed in an ordinance. The
following explains four main reasons.
CLUTTER
Clutter refers to excessive groupings of lights. Groupings of lights may generate
confusion, distract from obstacles, including those that they may be intended to
illuminate, and potentially cause accidents. Clutter is particularly noticeable on
roads where the street lights are badly designed, or where brightly lit advertising
surrounds the roadways. Depending on the motives of the person or organisation
who installed the lights, their placement and design may even be intended to
distract drivers, and can contribute to accidents.
OVERILLUMINA TION
Overillumination is the excess use of unnecessary light. Overillumination stems
from several factors:
. Improper design, especially of workplace spaces, by specifying higher
levels of light than needed for a given task.
. Incorrect choice of fixtures or globes, which do not direct light into areas
as needed .
. Improper selection of hardware to utilize more energy than needed to
accomplish the lighting task.
. Incomplete training of building managers and occupants to use lighting
systems efficiently.
. Inadequate lighting maintenance resulting in increased stray light and
energy costs.
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Most ofthese issues can
be readily corrected with
available, inexpensive
technology; however,
there is considerable
inertia in the field of
lighting design and with
landlord/tenant practices
that create barriers to
rapid correction of these
matters. Most importantly
public awareness needs
to improve dramatically for
industrialized countries to
realize the enormous payo1
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Local example of overillumination
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GLARE
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Glare is the result of excessive contrast between bright and dark areas in the
field of view. For example, glare can be associated with directly seeing the
filament of an unshielded or badly shielded light. Light shining into the eyes of
pedestrians and drivers can obscure night vision for up to an hour after exposure.
Caused by high contrast between light and dark areas, glare can also make it
difficult for the human eye to adjust to the differences in brightness.
Glare is particularly an issue in road safety, as bright and/or badly shielded lights
around roads may partially blind drivers or pedestrians unexpectedly, and
contribute to accidents. According to Bob Mizon, coordinator for the British
Astronomical Association's Campaign for Dark Skies, there are three types of
glare. Blinding Glare describes effects such as that caused by staring into the
sun. It is completely blinding and leaves temporary vision deficiencies. Disability
Glare describes effects such as being blinded by an oncoming cars brights,
significant reduction in. sight capabilities. Discomfort Glare does not typically
cause a dangerous situation in itself, and is annoying and irritating at best. It can
potentially cause fatigue if experienced over extended periods.
WASTED ENERGY
Energy is wasted when light does not fall on its intended target, as when lighting .
fixtures allow light to go up instead of (as is generally preferred) downward.
Waste also occurs when more light is generated than needed.
Local example of wasted energy
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LIGHT TRESPASS
Light trespass occurs when unwanted light enters one's property, for instance, by
shining over a neighbor's fence. A common light trespass problem occurs when a
strong light enters the window of one's home from outside, causing problems
such as sleep deprivation or the blocking of an evening view.
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Local example of light trespass
UP LIGHTING/SKY GLOW
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Sky glow refers to the "glow" effect that
can be seen over populated areas. It is
the combination of light reflected from
what it has illuminated and from all of
the badly directed light in that area,
being refracted in the surrounding
atmosphere. This refraction is strongly
related to the wavelength of the light.
Rayleigh scattering, which makes the
sky appear blue in the daytime, also
affects light that comes from the earth
into the sky and is then redirected to
become sky-glow, seen from the
ground. As a result, blue light
contributes significantly more to sky-
glow than an equal amount of yellow
light. Sky glow is of particular irritation to
astronomers, because it reduces
Local example of up lighting
contrast in the night sky to the extent where it may even become impossible to
see the brightest stars.
LAMPS. FIXTURES. AND LENSES USED IN OUTDOOR LIGHTING
LAMPS AND BULBS
There are many types of lamps used in outdoor lighting, a much greater variety
than are familiar to most lighting users. Each type has applications where it is
appropriate. Lighting designers must evaluate a variety of factors when choosing
lamps, including available luminous outputs, output maintenance (how the lamp's
output decreases with time), efficiency, capital costs, life cycle costs, color, size,
lifetime, turn-on characteristics, environmental factors such as hazardous
materials and effects on wildlife, and availability of fixtures. When decisions are
made about what kinds of lamps to use in a project or to require in a lighting
code, a consideration of all factors, both those advantageous and
disadvantageous for any given type, must be made.
Below are descriptions of the principle lighting types used for outdoor area
lighting and decoration.
Incandescent
Incandescent lamps are the lamps most familiar to
homeowners; they are commonly used for the majority of
residential lighting, both indoor and outdoor. They are
commonly used in applications where such low outputs are
needed and where the lighting is often switched off and on.
More than 95% of the energy used by incandescent lamps
goes into the production of heat. (It has been said that
incandescent lamps are really heat sources that happen to
produce a little light.) Advantages include low capital cost
for lamps and luminaires, wide availability, wide variety of
both lamp and fixture types, lack of a warm-up period, and
lack of hazardous wastes. Disadvantages include short
lifetimes (most less than a few thousand hours), low
efficiency (about 8-20 lumens/watt) with resultant high per-
lumen energy use and life cycle cost, attraction of insects, and high heat
production.
Fluorescent
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Fluorescent lamps are also seen in residential lighting, and they predominate in
indoor retail and office uses, and are occasionally seen in outdoor area lighting,
usually in smaller or older installations. A current-limiting device (ballast) is
required to operate these lamps, but they can typically be easily and immediately .
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switched on and off like incandescent lamps, and they reach nearly full output
almost immediately. Fluorescent lamps are also available in the so-called
"compact" styles. These "PL" fluorescents can make highly efficient and cost-
effective replacements for low-output residential lighting uses that are not too
frequently cycled off and on. Outputs up to about 8000 lumens are available
(about 2000 1m in "PL" styles). Advantages include low initial costs for lamps and
fixtures compared with the lamp types below, low life cycle costs and high
efficiency compared to incandescent (40-70 lumens/watt mean output), no warm-
up period, good color rendition, and long lifetimes (10,000 - 20,000 hrs).
Disadvantages include higher initial costs compared to incandescent lamps,
large lamp size, low efficiency (compared to lamp types below) and poor output
maintenance, attraction of insects, and potentially hazardous mercury waste.
Mercury Vapor (MV)
Mercury vapor lamps (sometimes called high-pressure mercury, as distinguished
from fluorescent) were the first widely used high-intensity discharge (HID)lamps.
Though highly efficient and long-lived compared to the incandescent lighting
technology they displaced after the second World War, they have many
disadvantages compared to other lighting sources available today, including low
luminous efficiency, poor color rendition, and high ultra-violet output. Mercury
vapor lamps have now been almost completely replaced in new applications by
the more efficient metal halide .and high-pressure sodium lamps. Several lighting
codes prohibit their use, though with mixed effectiveness. The technology is
moribund, and not often specified for any extensive commercial or public outdoor
lighting.
Metal Halide (MH)
Metal halide lamps are HID lamps, similar to mercury vapor lamps but with the
addition of small amounts of various metallic halides, such as scandium, sodium,
dysprosium, holmium and thulium iodide. A ballast is required, and full output is
not reached for 2-10 minutes after power is applied. The many different varieties
of metal halide lamps give a wide variety of slightly different color characteristics,
though generally they
are white or blue-white
sources. The
technology is still
evolving, and new
types are appearing
regularly. Besides a
relatively steep fall-off
in intensity with time
(compared to high-
pressure sodium; see
below), many metal
halide lamps also
change their color as they age. Metal halide lamps are very commonly used in
commercial outdoor lighting where white light with good color rendition is
required or simply desired, such as car dealer display lots, sports lighting, and
service station canopies. Advantages include a wide variety of moderate to high
luminous output lamps (3500 - 170,000 lumens mean output), high efficiency
compared to incandescent and mercury vapor (45 - 90 lumens/watt mean), and
good color rendition. Disadvantages include lower efficiency and output
maintenance compared to high- and low-pressure sodium, shorter lamp lifetime
compared to high-pressure sodium, color changes, ultra-violet output if not
adequately filtered, and potentially hazardous mercury waste.
High-Pressure Sodium (HPS)
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High-pressure sodium lamps are
currently the most widely used HID
lamps for roadway and parking lot
lighting, though in some areas metal
halide is becoming more popular.
Warm-up period is about 10 minutes.
Advantages include a long lifetime, a
wide variety of moderate to high
luminous output lamps (2000 -
120,000 lumens mean output), high
efficiency and good maintenance of
luminous output compared to all
lamp types except low-pressure
sodium, moderate color rendition
compared to low-pressure sodium,
and wide availability and moderate
cost of lamps and luminaires. Disadvantages include poorer color rendition than
metal halide, fluorescent and incandescent, poorer output maintenance and
efficiency than low-pressure sodium, and potentially hazardous mercury waste.
Low-Pressure Sodium (LPS)
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Low pressure sodium lights have low color rendition and are not common in the
United States. Low-pressure sodium lighting is favored where energy
consumption and costs are a major concern and where color discrimination is
either not needed or is supplied by other lighting. Advantages include the highest
luminous efficiency and lowest energy use, low glare associated with the. large
lamps, good visibility and low scattering, minimal effects on insects and other
wildlife, and lack of hazardous mercury wastes. Disadvantages include the lack
of color rendition, shorter lamp lifetime and higher lamp replacement costs
compared to HPS, and large lamp size in the higher output lamps.
Summary of Common Outdoor Lamp Types
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High-
Factor Incandescent Fluorescent Metal Halide Pressure
Sodium
Wattage 25-150 18-95 50-400 50-400
Output 210-2700 1000-7500 1900-30000 3600-46000
(lumens)
Lamp Life 750-2000 10000-20000 10000-20000 18000-24000
'hours)
Energy Use high medium medium low
Color good good ~ood moderate
Rendition
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LIGHTING FIXTURES AND LENS
Lighting Fixtures
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Cobra head
Wall pack
Shoe box
Halogen outdoor lamp
Lenses
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Full-cut off flat lens
Drop lens
Full-cut off verse drop-lens
Full-cutoff flat lens is preferable for reducing light pollution. It ensures that light is
only directed below the horizontal, which means less light is wasted through
directing it outwards and upwards.
Drop lens allows light to escape sideways and upwards, where it may cause
problems.
Most campaigners for the reduction of light pollution advocate the use of full
cutoff lighting fixtures as much as possible. It is also commonly recommended
that lights be spaced appropriately for maximum efficiency, and that lamps within
the fixtures not be overpowered.
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A full cutoff fixture, when correctly installed, reduces the chance for light to
escape above the plane of the horizontal. Light released above the horizontal
may sometimes be lighting an intended target, but often serves no purpose.
When it enters into the atmosphere, light contributes to sky glow. Some
governments and organisations are now considering, or have already
implemented, full cutoff fixtures in street lamps and stadium lighting.
By preventing light from escaping unnecessarily, the use offull cutoff fixtures
may help to reduce sky glow. Effects of glare may also be reduced, since by their
nature, full cutoff fixtures usually prevent luminaries from being directly visible. It
is also commonly argued by campaigners that full cutoff fixtures are more
efficient than other fixtures, since light that would otherwise have escaped into
the atmosphere is instead directed towards the ground.
The use of full cutoff fixtures may allow for lower powered bulbs to be used in the
fixture with the same, or sometimes better effect due to being more carefully
controlled. In every lighting system, some sky glow also results from light
reflected from the ground. This reflection can be reduced, however, by being
careful to avoid overpowering the lamp within the fixtures, and setting spacing
between lights appropriately ([NYSERDA-Planners],2002).
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A criticism of full cutoff lighting, particularly in the USA, is that luminaires with full
cutoff distributions typically have to be closer together than other light
distributions used to meet the same roadway lighting requirements specified by
the Illuminating Engineering Society of North America, of light level, uniformity
and glare (Keith, Journal of the Illuminating Engineering Society, 2000, 2002 and
2003). This means that using full cutoff luminaires corresponds to increased
initial costs, maintenance costs, operating costs, energy use, energy pollution,
and possibly light pollution, compared to using other distributions to meet the
same roadway lighting requirements
WHAT IS AN OUTDOOR LIGHTING CODE?
An outdoor lighting code is a legal document that establishes permitted and
prohibited lighting practices, with an emphasis on limiting obtrusive aspects of
lighting more than an emphasis on good lighting practices per se. Most lighting
codes are concerned primarily with limiting the wide-reaching effects of stray light
that causes glare, light trespass, sky glow, and limits the ability of persons to use
property in ways that do not want or need lighting. Lighting codes are often
included as a chapter of the zoning or land-use code, though zoning codes may
severely restrict enforcement options. The standards of a lighting code are
applied to new construction of all kinds in much the same way as a building code,
electrical code, or plumbing code, and consideration should be given to enacting
the lighting code using a similar legal structure to these. Lighting codes often
require some previously installed lighting to be brought into compliance
immediately or at some future date.
Lighting codes may be enacted at different governmental levels -- from state to
county or township and city and even development project or neighborhood.
State-level codes usually address only very general issues, though they may
nonetheless serve a valuable role, enabling the adoption of more comprehensive
codes at local levels. State-level codes also generally address lighting built with
state funding, such as state highways or for state-owned facilities that are often
legally exempt from local codes. They can also establish a basic code for areas
of the state that do not yet have or may never have more comprehensive codes.
At the development or subdivision level, lighting codes or restrictions can be
included in design standards or Conditions, Covenants, and Restrictions
(CC&Rs) to be applied only to the homes or developments within the subdivision.
Such codes are often the most effective vehicle to address specific residential
lighting issues such as shielding of low-output lighting that are often exempted in
higher-level lighting codes for practical reasons.
WHA T MAKES A LIGHTING CODE EFFECTIVE?
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The goal is the actual, real-life elimination of the adverse effects from outdoor .
lighting, such as light trespass, glare, energy waste, and sky glow. A good
lighting code is a vital step toward these goals, but actually achieving them
requires not only a lighting code, but also effective implementation and
enforcement of the code on an ongoing basis. After adoption, the code must lead
to quality lighting practices in the real world or it does not accomplish anything.
The actual adoption of a good lighting code for your community takes you
tt'}roljgtl. ttl~JiEst steps, but other steps must be accomplished if the overall goal is
to be realized. ..
1. Define the Problem
In most communities, even before you can hope to draft a lighting code, an
awareness of the issues and of the characteristics of quality lighting must be
built. This process starts first with any group that is especially motivated or
sensitive to the issues, including persons sensitive to the aesthetic character of
dark skies and/or the many values of quality lighting.
Through efforts at education this initial group then broadens the community's
awareness, in general and especially of the legislative bodies (councils or county
supervisors, for examples). Through this process a broad consensus will develop
both that there is a problem and that there are effective solutions.
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2. Draft and Enact a Lighting Code
Only then can the process begin to draft a code appropriate for the community,
and to take this code through the process of community review, enactment, and
implementation.
If careful consideration is not given in these first steps to the practical issues of
enforcement, adoption ofa good lighting code will not achieve the goal of quality
lighting and dark skies. To have a code that will be effective requires not only
careful consideration of the implications of the way the code standards are
written and compliance evaluated, it also requires that awareness and interest of
the community in the issues is maintained. Breakdown on these factors has been
the downfall of many otherwise technically correct lighting codes.
3. Enforcement and Monitoring
4. Stay Involved!
Practicality of implementation, application and enforcement are emphasized
again and again in this Handbook. Definitions must be clear and understandable;
rules must not only be technically correct and effective, they must also be
understandable and easily interpretable and enforceable; forms for .
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implementation and administration must be clear and understandable to lighting
users, lighting designers, and planning staff. Achieving these complex and
interrelated goals is challenging, but they must be successfully meshed if the
community is to see real improvements.
SHOULD A LIGHTING CODE LIMIT POLE HEIGHT?
Some communities have specified limits on the heights of lighting poles, either
through a lighting code or otherwise in development design standards. There can
-be twcfli1tentions here, bUfffferesults ofsUclirestrictions may not be what is
intended.
If the intention is to limit the daytime visual impact of taillight poles against
landscape views, then shorter poles may help, but lighting uniformity goals of the
designer may offset the gains from shorter poles by causing an increase in the
number of poles. More poles also are likely to cost more money to install and
operate.
If the intention is to limit the nightime visual impact of lights, in particular the
spread of light from high luminaires into surrounding areas (light trespass),
results may be much less than hoped. Again, since most area lighting has certain
target uniformity levels, shorter poles will mean that more must be used, which
may increase the visual impact at night as well as in the daytime. While these
poles will be shorter, a community must carefully evaluate whether the trade-off
of more poles might compromise the original intent to reduce visual clutter.
Unfortunately, in attempts to reduce costs, some designers will avoid increasing
the number of poles by using luminaires that have greater high-angle luminance,
that is, luminaires that throw more light to the side. These luminaires would
achieve the illuminance and uniformity specifications sought with fewer poles, but
will do so at the cost of increased glare. This will lead to increased light trespass,
just the opposite of what the goal may have been in restricting pole heights.
Visibility is likely to be compromised as well.
In general, it is not recommended that a lighting code limit pole heights. With
good designs using fully shielded luminaires, poles with standard heights (up to
about 11 meters or 35 feet) are in most situations minimally obtrusive. If there is
trouble in your community due to unusual circumstances or practice with the use
of unusually tall poles (over about 14 meters or 45 feet), then pole height
restrictions may be considered to address the problem, though it is not
recommended to restrict heights to much below about 8 meters (25 feet).
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