at the lrc

Light Pollution Research and Education Light Pollution Research and Education at the LRCat the LRC

Michele McColgan Ph. D.

Lighting Research CenterRensselaer Polytechnic Institute

Scope of PresentationScope of Presentation

� Developing a Light Pollution Program at the LRC

� Review Research and Education Projects

– ATM Lighting– Street lighting design tools for municipalities– Outdoor fixture testing (NLPIP)– Questions and answers (NLPIP) – Luminaire design and development (NYSERDA)– Luminaire cutoff classification and skyglow– Illuminated signs

LRC’sLRC’s Outdoor Lighting GoalsOutdoor Lighting Goals

Act as an independent facilitator for all stake-holders in outdoor lighting

– Bridge the lighting, astronomical, and environmental communities

– Provide a voice for outdoor lighting end-users

Perform objective research to assist in design, specification, and regulation of efficient outdoor lighting

Develop an outdoor lighting information resource

All of these goals require a common “vocabulary”/metrics

New LRC ProgramNew LRC ProgramInformation Resource on Information Resource on

Outdoor LightingOutdoor Lighting

No one resource available to obtain accurate, unbiased and timely information on the issues of light pollution and outdoor lighting

Decisions are being made about outdoor lighting based on few or incorrect facts

– Often resulting in unintended consequences with negative impacts on design performance, light pollution or energy use

The LRC is creating a collection of information on the topic of light pollution and energy efficient outdoor lighting

– The ultimate goal being to provide decision makers, specifiers, and designers with up to date and reviewed information that is based on sound scientific study

Information Resource Information Resource on Outdoor Lightingon Outdoor LightingDevelopment of this resource will have two benefits:

• Access to data will help decision makers make the correct choices to ensure that light pollution concerns are met without compromising safety or energy efficiency

• Additionally, gaps in the collective knowledge will become evident

Possible topics include: • Light pollution metrics• Proposed and current lighting legislation• Design guides• Demonstrations and evaluations• System design and energy use• Research results • New specifications, standards, and classifications• Testing reports• Education, seminars, and conference presentations

NYS ATM Safety ActNYS ATM Safety Act

� 3,562 ATM locations in NYS as of 12/31/02

� ATMs positioned in an outside wall, or inside the building, or in a drive-through facility.

� ATM Safety Act of NYS was – Signed into law on February 6, 1996 – Effective on January 1, 1997

� Objective is to ensure the safety and convenience of consumers using ATMs

� Among its provisions is a requirement for adequate lighting to be provided at ATM facilities

Definition ofDefinition of“Adequate Lighting”“Adequate Lighting”

Enforcement and Enforcement and ComplaintsComplaints

� ATM Safety Act enforced by NYS Banking Dept using a team of inspectors

� ATM facilities inspected once a year� Many ATM facilities fail to meet the requirements of the ATM

Safety Act� Most frequent cause of failure is inadequate lighting at 50 ft

from the ATM � Outcome of this process of inspection is powerful floodlights on

or around bank buildings� Complaints range from

– Neighbors about light trespass – Customers and drivers about visual discomfort at night– Municipalities about the inappropriateness of the lighting

ObjectivesObjectives

� Propose modifications to the lighting requirements of the ATM Safety Act

� Modifications have been developed to meet a series of objectives:

– To maintain the level of safety perceived by users of ATMs to that experienced at ATMs illuminated to the current lighting requirements

– To reduce the visual discomfort experienced by users of ATMs andpassing drivers

– To reduce light trespass from ATM lighting onto adjacent properties

– To provide an easily enforceable set of lighting recommendations

– To provide a set of lighting recommendations that can be met using commercially available equipment

ModificationsModifications

� The proposed changes to the Safety Act relevant to lighting are of six types– moving measurement locations and/or distances

• Removal of distinction between 50 ft or 60 ft• Removal of lighting around the corner• Movement of the measurement points to ground level at 30 ft from the

ATM– changing illuminance levels

• Reduction in the minimum illuminance within 5 ft of an external ATM to 5 fc

– changing units of measurement• Change in the units of measurement for illuminance to footcandles (fc)

– method to limit light trespass and glare• Introduction of two alternative criteria at a distance of 60 ft from the

ATM

Enforcement Enforcement -- Selection of Selection of measurement positions measurement positions

Enforcement Enforcement -- Selection of Selection of measurement positions measurement positions –– con’tcon’t

� Section through planHorizontalmeasurements

Verticalmeasurements

COMPARISON OF VEILING LUMINANCE COMPARISON OF VEILING LUMINANCE FOR ROADWAY LIGHTINGFOR ROADWAY LIGHTING

� Evaluate veiling luminance as a driver approaches streetlights

� Are cutoff classifications predictive of the overall glare?

� Computer simulation using ies files of luminaires

� Veiling luminance calculated at difference distances from the luminaire

� 18 fixtures compared– 4 full cutoff, 7 cutoff, 7 semicutoff– 250 W, 27 MH

� Effects this might have on vision, particularly considering re-adaptation

COMPARISON OF VEILING LUMINANCE COMPARISON OF VEILING LUMINANCE FOR ROADWAY LIGHTINGFOR ROADWAY LIGHTING

Veiling LuminanceVeiling Luminance

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 20 40 60 80 100 120 140 160 180 200

Position dow n the road (feet)

Veili

ng lu

min

ance

(cd/

m^2

)

Full cutoff fixtures

Cutoff fixtures

Semicutoff fixtures

2

10θ

⋅= glare

veil

EL

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 20 40 60 80 100 120 140 160 180 200


Veili

ng lu

min

ance

(cd/

m^2

)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 20 40 60 80 100 120 140 160 180 200


Veili

ng lu

min

ance

(cd/

m^2

)

Cutoff classifications and GlareCutoff classifications and Glarewhat does 0.7 mean? Good or bad?what does 0.7 mean? Good or bad?

80˚74˚70˚

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 20 40 60 80 100 120 140 160 180 200


Veili

ng L

umin

ance

(cd/

m^2

)

Full cutof f

Cutof f

Semicutof f

Overall Glare “Dosage” Overall Glare “Dosage” Area under Each Veiling Luminance CurveArea under Each Veiling Luminance Curve

area

0

1

2

3

4

5

6

7

Full cutof f Cutof f Semicutof f

Cutoff class ification

Ave

rage

Are

a U

nder

Vei

ling

Lum

inan

ce C

urve

(cd/

m^2

)

Maximum Value of GlareMaximum Value of Glaremax

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Full cutof f Cutof f Semicutof f

Cutoff Class ification

Ave

rage

Max

imum

of t

he V

eilin

g Lu

min

ance

cur

ve (c

d/m

^2)

ReRe--Adaptation TimeAdaptation Time

� Speed of the car is 30mph, a distance of 200 feet is covered in approximately 4.5 s

� Veiling luminance curves of the full cutoff fixtures are pulses of roughly 1 s

� Eye is attempting to re-adapt each time it passes the high narrow peak of the full cutoff fixtures

� Eye at a more constant adaptation for the fixtures with a wider pulse

COMPARISON OF VEILING LUMINANCE COMPARISON OF VEILING LUMINANCE FOR ROADWAY LIGHTINGFOR ROADWAY LIGHTING� Cutoff classification is predictive of the amount of

glare far from the fixture� Cutoff classifications are not predictive of the relative

amount of glare produced near the fixture� Re-adaptation time and maximum veiling luminance

value are important for visual performance� Eye is attempting to re-adapt each time it passes the

high narrow peak of the full cutoff fixtures

Product TestingProduct Testing

� NLPIP (National Lighting Product Information Program)

� http://www.lrc.rpi.edu/nlpip/index.cfm

Update Specifier ReportUpdate Specifier Report� Original published in 1993� Has become outdated

– No full cutoff classification– Not much consideration of

light pollution concerns– More products currently

available

Specifier ReportSpecifier Report Update GoalsUpdate Goals

� Expand scope of the earlier report

� Provide manufacturer’s data

� Include product testing

– Full 360o intensity characterization– Finer angular increments above

the luminaire and in the glare zone– Spot check manufacturers info

� Explore light pollution issues

– Uplight (reflected and direct), trespass, and glare

� Include further calculation and analysis

– Glare– Uplight– Light Trespass– Energy usage

Light Fixture ClassificationLight Fixture Classification

� Currently there exists no one standard way to classify outdoor lighting fixtures– Fixtures classified by:

• Lamp type• Wattage• Shape• Optics• Cutoff classification• Light distribution (throw)

� One challenge for this report is to determine a classification methodology for reporting and testing– Most probably be a combination approach

Shoebox

Cobrahead

Post Top

Manufacturer Supplied Data Manufacturer Supplied Data Isocandela PlotsIsocandela Plots

Red indicates vertical angles, blue indicates horizontal angles

No data above 90oData reported above 90o

Fixture SelectionFixture Selection

Cutoff Classification

# of Test Samples

Product Type*

Source Type**

Lamp Orientation*** Lamp Wattage

2 H2 V2 H2 V2 H2 V2 H2 V2 H2 V2 H2 V2 H2 V2 H2 V2 H2 V

*Note: product type names used here are placeholders for discussion**HPS: high pressure sodium, MH: metal halide***H horizontal, V vertical

MH

MH

MH

Mid range of typical wattages used in

application (distribution scales with wattage)





Semi Cutoff 12

Shoebox

Cobrahead

Functional Post Top

Full Cutoff

Cutoff 12

Shoebox

Cobrahead

Functional Post Top

Shoebox

Cobrahead

Functional Post Top

12

List of Fixtures to be TestedList of Fixtures to be Tested

Manufacturer Fixture Manufacturer Fixture Manufacturer Fixturehoriz Gardco Gullwing GE M400 Full Cutoff Emco Ecoround_ERP

Kim Archetype_AR Lithonia CHM Sterner Berkley

vert LSI Hilton II WideLite Effex

Ruud S3V1_2 Streetworks Galleria Area Light

horiz Widelite Excelyte 400 GE M-400 Cutoff Kim Curvilinear_Cutoff_CC_CCS

Lumark Hammer Streetworks OVF-Flat_Glass US Arch. Ltg SVLPT222

vert Spaulding Proformer ExcelLine V ertilyteHolophane Mongoose Bieber PCV_Round_Darksky

horiz Visionaire Ltg Toronto Lumec Helios HBS or HBM

Lithonia replaced with 115

vert Stonco SVL_SeriesLumec Citea SCB

CSC

Shoebox Cobrahead Posttop

FC

Light Trespass and GlareLight Trespass and GlareHouse-Side Vertical Illuminance at 5 feet

0

5

10

15

20

25

30-1

00 -90

-80

-70

-60

-50

-40

-30

-20

-10 0

Distance behind pole (feet)

Ave

rage

Ver

tical

Illu

min

ance

(lux

)

Road-Side Vertical Illuminance at 5 feet

0

5

10

15

20

25

30

0 10 20 30 40 50 60 70 80 90 100

Distance in front of pole (feet)

Ave

rage

Ver

tical

Illu

min

ance

(lux

)

3 MH2 MH1 MH

Vertical Illuminance down the road at height of 4 feet

0

5

10

15

20

25

30

0 10 20 30 40 50 60 70 80 90 100

Distance to right of pole (feet)

Ave

rage

Ver

tical

Illu

min

ance

(lux

)

3 MH2 MH1 MH

Uplight 2135˚ – 180˚

Uplight 190˚ – 135˚

Luminaire (30’ high)

Ground PlaneR = 0.2

UplightUplight MetricMetric

Direct and Reflected Direct and Reflected UplightUplight MetricMetric

500

1500

2500

3500

4500

Cutoff classification

Dire

ct a

nd re

flect

ed u

plig

ht (l

umen

s)

Zone 1Zone 2Zone 3

C FCSC C FCSC C FCSC

Light Pollution IndexLight Pollution Index

Parking Lot – Daytime ViewParking Lot – Nighttime View

Parking Lot – Nighttime Computer Simulation

LPI = The lumen value on each virtual plane (pollutant lumens)

by the lumens on the ground (useful lumens);

LPI vs. IESNA Cutoff Classification

Overall Results Overall Results –– Luminaire LayoutsLuminaire Layouts

Optical System vs. LPI

Overall Results Overall Results –– Luminaire LayoutsLuminaire Layouts

Luminaire Efficiency vs. LPI – as per IESNA Classification System

Luminaire Classification SystemLuminaire Classification System

� Extension to Bullough’s system (2002) suggested by author: 8 classes;

� They attempt to consider all the critical zones above and around the luminaire after ground reflection, and are defined as follows:

More than 20%More than 20%Class-8

No more than 20%More than 20%Class-7

No more than 20%No more than 20%Class-6





0%No more than 5%Class-1

%age of Luminous Flux emitted upper-sideways (Zone-2) after reflection

%age of Luminous Flux emitted upwards (Zone-3) after reflection

Suggested Classification System

LPI vs. Author’s Luminaire Classification

Luminaire Efficiency vs. LPI – as per Author’s Classification System

Smart Roadway LightingSmart Roadway Lighting

� The LRC will develop two types of lighting elements:

1. Street lighting fixtures � Use less energy� Light roadways more effectively� Greatly reduce the amount of stray light

2. An integrated, “intelligent” roadway marking system � For hazardous areas such as SPUIs, highway exit and entrance

ramps, sharp curves, or pedestrian crossings� Using low-mounted solid-state lighting equipment LEDs� These devices may also give drivers information about road

conditions, upcoming accidents, hazards, or pedestrians entering the road

Luminaire Design ConsiderationsLuminaire Design Considerations

� What is the application?– Roadway

• What is the road surface?– Parking lot– Area/pathway

� What are the objectives?– Safety – driver/pedestrian– Security– Economic development– Esthetics

� What light levels are required?� Appropriate beam distribution?� How can energy use be minimized?

– Lower wattage– Fewer poles

� What are acceptable limits for glare?– Baseline offensive glare levels on full cutoff

� How to minimize trespass/sky glow?

Direct and reflected candela distributionDirect and reflected candela distribution

LRC FixtureLRC Fixture

90° 180° 80° +

Light trespass Glare

Performance

72.5°77.5° 0°45° 0°70°

62.5°60°

Intelligent RoadwayIntelligent RoadwayMarkersMarkers

� Beam distribution and marker orientation are important

� Self luminous markers provide more way finding than reflective markers

www.reflecto.co.uk

Tools for MunicipalitiesTools for Municipalities

� White paper� Checklist� Street Lighting Design

Patterns� Seminar� Sponsor CL&P

www.lrc.rpi.edu/programs/transportation/index.asp

White PaperWhite PaperEFFICIENT STREET LIGHTING EFFICIENT STREET LIGHTING

AND LIGHT POLLUTIONAND LIGHT POLLUTION

Scope of this document– Provide information to lighting decision makers in the state of

Connecticut about street lighting and light pollution

– This document:• Outlines current Connecticut legislation • Defines light pollution • Discusses lighting considerations that should be considered before

embarking on a lighting project, • Summarizes good lighting practice

– Is intended to be used with companion documents• Checklist and design guide

How to Use the ChecklistHow to Use the Checklist

Design GuideDesign GuideEfficient Street Lighting Design Efficient Street Lighting Design

GuideGuideScope of document

– This guide is designed to aid Connecticut municipalities in designing and specifying energy efficient street lighting to meet their illumination goals

• The intent of this guide is to provide illustrative examples of typical street lighting designs and present alternative options

• Although all possible outdoor lighting scenarios cannot be illustrated in this document, it is presented as a tool to identify practical approaches that consider light pollution issues

Example I: a cul de sac with a diameter of about 53’-0”in a residential setting has been usedGoal: To illustrate how uniformity and light distribution change for various wattages for two different full cutoff luminaires mounted at different heights.

A

B

A. Lighting Scheme

GE SL_C_70WHPS_6300_14_2.40_7.30_24.00

B. Lighting Scheme

GEM250_FC_70WHPS_6300_27_1.50_4.10_15.00

NLPIP Lighting Answers Light PollutionNLPIP Lighting Answers Light PollutionQuestions and Answers

– What is light pollution?– What is sky glow? – What is light trespass? – What is glare? – How is the issue of light pollution currently

being addressed?– What are lighting environmental zones?– How are luminaires evaluated for their

potential to contribute to light pollution or light trespass?

– What are the IESNA cutoff classifications?– Are the IESNA cutoff classifications a good

indicator of direct uplight?– What is the difference between full cutoff

and fully shielded?

� www.lrc.rpi.edu/nlpip/lightinganswers.cfm

ConclusionsConclusionsDecisions are being made about outdoor lighting based on few or

incorrect facts– often resulting in unintended consequences with negative impacts

on design performance, light pollution, or energy use

The LRC is creating a collection of information on the topic of light pollution and energy efficient outdoor lighting

– The ultimate goal being to provide decision makers, specifiers, and designers with up to date and reviewed information that is basedon sound scientific study

� Common metrics/vocabulary are needed to meet various objectives

www.lrc.rpi.edu/programs/transportation/index.asp

at the lrc

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