21st Century Security and CPTED, 2nd Edition

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30

Security Lighting: Part 2

WHAT IS GOOD LIGHTING?

Good outdoor lighting improves the ability to have natural surveillance and good visibility, which

creates a sense of security and safety, and should also minimize energy usage, operating costs,

and the obtrusive and imposing glare. Many outdoor lights are improperly designed and improp-

erly aimed, resulting in a costly, wasteful, and distracting glare of light (Good Neighbor Outdoor

Lighting 2006). Explore the use of new lighting sources currently under development, such as

induction and LEDs, that are more energy efcient, generate similar light levels, and are cheaper to

operate than metal-halide or mercury-vapor lamp installations.

GLARE

If a person can see a bright bulb from a distance (more than 100 ft), the lighting is producing glare

horizontally, rather than vertically down on the ground it is supposed to be lighting. Glare can

produce both discomfort and disability. The glare interferes with the vision of drivers, pedestrians,

security cameras, and cyclists.

LIGHT TRESPASS

Light trespass is referred to lighting that creeps past the boundaries of the intended property and

imposed on adjoining properties. The imposing, unintended light shines into bedroom windows,

reducing privacy, and resulting in shades and windows being closed that takes away the benets of

natural surveillance and eyes on the street.

CONTENTS

What Is Good Lighting? ................................................................................................................. 763

Glare ...............................................................................................................................................763

Light Trespass ................................................................................................................................ 763

Light Pollution ...............................................................................................................................764

What Can We Do? (Good Neighbor Outdoor Lighting 2006) .......................................................765

Minimum Lighting Guidelines ...................................................................................................... 765

Recommended CPTED Lighting Strategies .................................................................................. 767

Demand Lighting ...................................................................................................................... 767

Overlapping Techniques ............................................................................................................ 767

Color Rendition ......................................................................................................................... 768

Coordination with Street Elements ................................................................................................ 768

Backup and Recovery Systems .................................................................................................768

Painting the Surfaces around Ceiling Lighting with Light Colors to Reect the Light ............770

Darkness Can Be a Legitimate CPTED Lighting Strategy .......................................................770

Quality of Lighting ....................................................................................................................772

Conduct Lighting Survey, Also Known as a Photometric Plan ................................................. 774

Coordination between the Trades .............................................................................................. 776

Summary ........................................................................................................................................778

Other Resources .............................................................................................................................778

764 21st Century Security and CPTED

LIGHT POLLUTION

Light pollution is produced by the use of ever brighter outdoor night lighting that is often used

for the advertising of gas stations, convenience stores, and shopping centers. It is often justied

in the name of security. Since the 1960s, we have seen the increased outdoor use of high-intensity

discharge (HID) lamps. Light pollution is light that is not targeted for a specic task, is bright and

uncomfortable to the human eye, causes unsafe glare to drivers and pedestrians, harms the biologi-

cal integrity of ecosystems, causes light to trespass into homes and bedrooms, and creates skyglow

above cities. Skyglow obliterates our views of the stars and planets. It also wastes energy by shining

non-targeted light upward into space.

Light pollution has been recognized as both a quality-of-life and an environmental issue for

years (www.darksky.org), but only recently has the use of light at night attracted the attention of

health researchers. We know now that articial light acts like a drug in its ability to disrupt the

biological clocks of living organisms (see Figure 30.1).

Unshielded floodlights

or poorly-shielded floodlights

Fixtures that shield the light source to minimize glare and light trespa

ss

and to facilitate better vision at night

Examples of acceptable/unacceptable lighting fixtures

Acceptable

Full cutoff fixtures

Full cutoff streetlight

Fully shielded fixtures

Fully shielded

“period” style

fixtures

Unshielded

“period” style

fixtures

Bulb shielded

in opaque top

Fully shielded

security light

Shielded/properly-aimed

PAR floodlights

Flush mounted canopy

fixtures

Drop-lens canopy

fixtures

Fully shielded

wallpack and wall

mount fixtures

Unacceptable/discouraged

Fixtures that produces glare and light trespass

Unshielded wallpacks and

unshielded or poorly-shielded

wall mount fixtures

Drop-lens and sag-lens fixtures

w/exposed bulb/refractor lens

Unshielded streetlight

Unshielded

security light

Unshielded PAR

floodlights

FIGURE 30.1 Acceptable and unacceptable light luminaires for light trespass. (Copyright 2005 by

BobCrelin, Used with permission from the artist, Rendered for the Town of East Hampton, New York.)