|
Resources
<br />
<br />Illuminating Engineering' Society
<br /> of North America
<br />3~5 East ~7th St.
<br />New York, NY 10017
<br />212-705-7913
<br />International Dark Sky A~soclation
<br />35~5 North Stewart
<br />Tucson, AZ 85716
<br />New England Light Pollution
<br /> Advisory Group
<br />Daniel W.E. Green
<br />Smithsonian Astrophysica~l Observato~
<br />60 Garden Street
<br />Cambridge, MA 02138
<br />
<br />Debra L. Sachs--Principal Investigator
<br />Michael Munson
<br />11 Pearl St.
<br />Essex Junction, VT 05452
<br />802-879-0605
<br />Urba~n Consortium Energj' Task Force
<br />Chittenden County Regional
<br /> Planning Commission
<br />P.O. Box 108
<br />Essex Junction, VT 05453
<br />802-658-3004
<br />
<br />De Chiara, Joseph and Lee Koppelman,
<br /> Site Planning Standards, New York:
<br /> McGraw-Hill, 1978.
<br />Kendig, Lane, with Susan Connor,
<br /> Cranston Byrd, and Judy Heyman,
<br /> Performance Zoning, Chicago: APA
<br /> Planners Press, 1980.
<br />Listokin, David and Carole Walker, The
<br /> Subdivision and Site Plan Handbook,
<br /> New Brunswick, N.J.: Center for
<br /> Urban Policy Research, Rutgers
<br /> University, 1989.
<br />Smith, Thomas P., The Aesthetics of
<br /> Parking, PAS Report No. 411,
<br /> Chicago: APA 1988.
<br />
<br />provided at intersections;along walkways, at entryways, between
<br />buildings, and in parking are~. They also advise more lighting on
<br />commercial than on residential streets. As to the spacing and
<br />height of light fixtures, they stiggest:
<br />· Spacing of standards shallabe equal to approximately four
<br /> times the height of the st{ndard.
<br />· The maximum height ofst~dards shall not exceed the maxi-
<br /> mum building height perm!tted, or 25 feet, whichever is less.
<br />
<br />· The height and shielding o~lighting standards'shall provide
<br /> proper lighting without haz~ rd to drivers or nuisance to residents.
<br />
<br /> The authors do not specifY standards for shielding, but many
<br />lighting professionals say onlf full cutoffshields, which allow no
<br />light above a horizontal plan~., are acceptable. Lane Kendig, in
<br />Performance Zoning (APA Pldnners Press, 1980), says a light
<br />fixture's maximum height should depend on the amount of
<br />shielding provided.
<br />
<br /> Many uses have the option of providing a lower light post with
<br /> a noncutofftype luminaire oi a higher pole, up to sixty (60) feet
<br /> with a luminaire that totally Cuts offlight spillover at a cutoff
<br /> angle smaller than ninety (90) degrees.
<br /> Kendig exempts outdoor lighting for night sports facilities
<br /> such as baseball diamonds, playing fields, and tennis courts
<br /> but requires that the illumi~jation source be shielded at a 90-
<br /> degree angle.
<br />
<br /> The IES recommends two footcandles of illumination for
<br /> pedestrians to have good perception of obstacles more than 50
<br /> feet away on a street or sidewalk. It recommends two
<br /> footcandles for attendant par~ing in a commercial area and one
<br /> for self-parking. In Site Plann/ng Standards, De Chiara and
<br /> Koppelman concur, but somA parking consultants advise that
<br /> the real or perceived dangers hfparking environments require
<br /> an average of five footcandlesrfor adequate safety.
<br />
<br />Cutoff Type Luminaire: a unit of
<br /> illumination with elements such as
<br /> shield, reflectors, or refractor
<br /> panels that direct and cut off the
<br /> light at a cutoff angle less than 90
<br /> degrees.
<br />Footcandle: a unit of illumination
<br /> produced on a surface, all points of
<br /> which are one foot from a uniform
<br /> point source of one candle.
<br />Glare: light emitting from a luminaire
<br /> with an intensity great enough to
<br /> reduce a viewers' ability to see and,
<br /> in extreme cases, causing momentary
<br /> blindness.
<br />Light Trespass: the shining of light
<br /> produced by a luminaire beyond the
<br /> boundaries of the property on which
<br />
<br />Cutoff: the point at which all light rays it is located.
<br />emitted by a lamp, light source, or Luminaire: a complete lighting unit
<br />luminaire are completely eliminated ' Consisting ora light source and all
<br />(cut off) at a specific angle above the necessary mechanical, elec[rical, and
<br />ground. . decorative parts. ':
<br />CutoffAngle: the angle formed by a line : ~ i. :ii
<br /> · drawn from the direction of light rays at. Alldefinitions areJTorn Performance
<br /> the light source and a line perpendicular: i Zoning, except definitions of light
<br /> to the ground from the light source, trespass andglare, which comeaffora the
<br /> above which no light is emitted. · Kehnebunkport, Maine, ordinance.
<br />
<br /> Glare and Light
<br /> Below are some examples of zoning ordinances that regulate
<br /> glare and light spill by prescribing a combination of luminaire
<br /> height, cutoff shields, and precise footcandle measurements.
<br /> Greenwich, Conneetlcut, requires that, 'with some exceptions,
<br /> all light sources be shielded so that, "[a]djacent to business uses,
<br /> the light source shall not be visible at a height greater than five
<br /> (5) feet above ground level" and "[a]djacent to residential uses,
<br /> the light source shall not be visible at ground level or above." Any
<br /> type of uplighting that is not lighting buildings, trees, shrubs, or
<br /> site surfaces is prohibited. This ordinance does not differentiate
<br /> between residential and business zones except that perimeter
<br /> lighting in residential zones must be limited to 0.1 footcandle
<br /> anywhere .along a property line.
<br /> Vai~ Colorado, requires that developers submit an outdoor
<br /> lighting plan "separately from the site plan or landscape plan, and
<br /> ·.. show the location, the height above grade, the type of
<br /> illumination (such as incandescent, halogen, high-pressure
<br /> sodium etc.), the source lumens, and the luminous area for each
<br /> source light which is proposed." A pole light may not be higher
<br /> than 35 feet in a commercial area, eight feet in a residential area,
<br /> or eight feet in either if "affixed to vegetation." In commercial
<br /> areas, all light sources higher than 15 feet must be fitted with a
<br /> full cutoff shield. All flashing lights are prohibited.
<br /> Eatontown, New Jersey. The light pollution ordinance
<br /> requires that, "at the property line of subject property
<br /> illumination from light fixtures shall not exceed 0.1 footcandles
<br /> on residentially zoned property or 0.5 footcandles on business
<br /> zoned property, measured on a vertical plane." IES
<br /> recommended levels are to be used in roadway lighting, parking
<br /> lots, and recreational and sports facilities. Shielding is required
<br /> on almost all outdoor lighting.
<br /> Bronxville, New York, is still lit mainly by incandescent
<br /> lighting. Provision is made for some fluorescent and metal
<br /> halide lamps, but high- and low-pressure sodium, mercury-
<br />
<br />
<br />
|