HomeMy WebLinkAboutLighting Standards 10-28-2020
BOZEMAN LIGHTING AND ELECTRICAL SPECIFICATIONS
CONTENTS:
Standard Specifications for Lighting Materials and Installations
Street & Pedestrian Lighting Luminaire Submittal Form
Standard Drawings
Street Lighting – Method of Measurement
Street Lighting – Luminance Method of Measurement
Street Lighting – Step-by-Step Luminance Method of Measurement
Street Lighting Measurement Form (Excel Document, fillable form)
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Table of Contents
Section I. General ....................................................................................................... 3
Section II. Definitions ............................................................................................... 3
Section III. Scope of Work. ....................................................................................... 4
A. General ........................................................................................................................... 4
Section IV. Control of Work ...................................................................................... 4
A. General ........................................................................................................................... 4
B. Deviation Request ........................................................................................................... 5
Section V. Utility Clearances ................................................................................... 5
A. Overhead Powerline Clearances ..................................................................................... 5
B. Below-grade Utility Clearances ........................................................................................ 5
Section VI. Conduit .................................................................................................... 5
A. Plastic Conduit - PVC ...................................................................................................... 5
B. Plastic Conduit – HDPE ................................................................................................... 6
C. Steel Conduit ................................................................................................................... 6
D. Conduit Installation .......................................................................................................... 6
Section VII. Pull Boxes / Splice Boxes ...................................................................... 7
A. General ........................................................................................................................... 7
B. Pull Box / Splice Box Installation ..................................................................................... 7
Section VIII. Concrete Foundations ........................................................................ 8
A. Light Standard Foundations............................................................................................. 8
B. Concrete Foundation Pads .............................................................................................. 8
C. Concrete Fill for Pedestal Type Cabinets ......................................................................... 8
Section IX. Wiring ...................................................................................................... 9
A. General ........................................................................................................................... 9
Section X. Bonding and Grounding ........................................................................ 9
A. General ........................................................................................................................... 9
Section XI. Lighting Control Centers and Metered Pedestals ............................. 10
A. General ..........................................................................................................................10
B. Installation ......................................................................................................................10
Section XII. Lighting Design Criteria ....................................................................... 11
A. General ............................................................................ Error! Bookmark not defined.
B. Correlated Color Temperature (CCT) ............................... Error! Bookmark not defined.
All luminaires shall have a Correlated Color Temperature (CCT) of 2700K - 3000K (+/- 275K).
................................................................................................ Error! Bookmark not defined.
C. Non-Signalized Intersection ............................................................................................11
D. Signalized Intersections .................................................... Error! Bookmark not defined.
E. Intersections of Pathways and Streets ............................................................................12
F. Continuous Lighting on Streets .......................................................................................14
G. Design Considerations. ...............................................................................................16
H. Pedestrian Lighting. ........................................................................................................18
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
I. Pathway Lighting. ...........................................................................................................18
Section XIII. Streetlight Luminaires ...................................................................... 19
A. General ..........................................................................................................................19
B. Installation ......................................................................................................................20
C. Approved Manufacturers – Cobrahead Style [Refer to Figure 10 – Typical Streetlight
Standard Detail] .....................................................................................................................20
D. Approved Manufacturers – Bell Style [Refer to Figure 10 – Typical Streetlight Standard
Detail] ....................................................................................................................................20
Section XIV. Pedestrian Luminaires ...................................................................... 20
A. General ..........................................................................................................................20
B. Installation ......................................................................................................................21
C. Approved Products – Traditional Post-top Style [Refer to Figure 11 – Typical Post-Top
Pedestrian Light Standard Detail] ..........................................................................................21
D. Approved Products – Bell Style [Refer to Figure 12 – Typical Arm-Mount Pedestrian Light
Standard Detail] .....................................................................................................................21
Section XV. Pathway Luminaires ......................................................................... 21
A. General ..........................................................................................................................21
B. Installation ......................................................................................................................22
C. Approved Products .........................................................................................................22
Section XVI. Poles. ................................................................................................. 22
A. General ..........................................................................................................................22
B. Installation ......................................................................................................................23
Section XVII. Pole bases ......................................................................................... 23
A. General ..........................................................................................................................23
B. Breakaway Bolt Couplings. .............................................................................................23
C. Frangible Transformer Base. ..........................................................................................23
D. Non-Breakaway Anchor Base. ........................................................................................23
Section XVIII. Submittal Requirements ................................................................... 24
A. General ..........................................................................................................................24
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Section I. General
These specifications for the provision of lighting installations are intended to provide a set of
minimum standards that shall be followed for street lighting, pedestrian lighting and pathway
lighting installations within the City of Bozeman public right-of-way or property. These standards,
plans, and any special provisions shall apply to all materials supplied, methods, and procedures
of work to be followed, and other general minimum requirements that shall be complied with
before work is accepted by the City of Bozeman.
The City of Bozeman has adopted the following as part of these standard specifications:
A Standard Specifications for Road and Bridge Construction (latest edition), Montana
Department of Transportation, and all amendments and revisions pertaining thereto.
B Manual on Uniform Traffic Control Devices (latest edition), Federal Highway
Administration.
C NFPA 70 - National Electrical Code (latest edition)
D NESC - National Electrical Safety Code
The standard specifications outlined in this document are revisions and amendments to the
Montana Department of Transportation Standard Specifications for Road and Bridge
Construction. In situations where there is a conflict or question of interpretation, these
specifications and any special provisions shall prevail.
These specifications, the plans, any special provisions, and all supplemental documents are
essential parts of a contract and a requirement occurring in one is as binding as though occurring
in all. They are intended to be complementary and to describe and provide for the complete work.
In case of a discrepancy, figured dimensions shall govern over scaled dimensions; plans shall
govern over standard specifications; and special provisions shall govern over plans and standard
specifications.
Section II. Definitions
Development Review Committee (DRC) evaluates all proposals subject to the provisions of
Chapter 38, the Unified Development Code within the Bozeman Municipal Code. The DRC is
charged with reviewing items related to public health and safety.
Low Pedestrian Conflict occurs when adjacent to residential, rural or industrial land uses with
very low volumes of nighttime pedestrian usage. These can occur in any of the cited street
classifications but are typically suburban streets with single family dwellings, multi-family
residential developments, and rural or semi-rural areas.
Medium Pedestrian Conflict occurs when adjacent to commercial and institutional land uses
where a moderate numbers of pedestrians utilize the streets at night. Typical are downtown
office areas, blocks with libraries, schools, churches, shopping centers, restaurants, parks, and
streets with transit lines.
Pathway lighting is provided to light trails and pathways that are not adjacent to streets.
Pathway lighting assemblies are typically 36 inches to 48 inches. The distribution of the light is
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
directed towards the trail or pathway.
Pedestrian lighting is provided to light the sidewalk (attached or detached) along arterial,
collector, local streets, public plazas, trails or other pedestrian areas. Pedestrian lighting
assemblies are typically between 12 feet to 15 feet. The distribution of the light is directed
towards the sidewalk.
Special Improvement Lighting District (SILD) an improvement district embracing street or
streets or public highway therein or portions thereof and property adjacent thereto or property
which may be declared by said council to be benefitted by the improvement to be made for the
purpose of lighting such street or streets or public highway. All or any portion of the cost of
installing and maintaining such lighting system is required to be paid by the owners of the
property embraced within the boundaries of such districts.
Street lighting is provided for arterial, collector, and local streets where pedestrians and cyclists
are generally present. The primary purpose of street lighting is to help the motorist identify
obstacles, provide adequate visibility of pedestrians and cyclists, and assist in visual search
tasks, both on and adjacent to the street. Street lighting assemblies are typically between 25
feet and 40 feet. The distribution of the light is directed towards the street.
Section III. Scope of Work.
A. General
The design engineer shall consider the need for street lighting, pedestrian lighting and pathway
lighting, as specified in Section XII Lighting Criteria, in the development plans for any new or
reconstructed roadways. The guidelines and specifications outlined here shall be applicable to
lighting located within the City’s Right of Way.
All street, pedestrian and pathway lighting shall be operated and maintained through the
creation of a new SILD, through the annexation to an existing SILD or through some other
equivalent means approved by the City of Bozeman. The application to create or annex to an
existing SILD shall be submitted to the City within two months of preliminary approval of the
development. The approval to create or annex to an SILD shall be granted prior to final plat for a
subdivision or Occupancy if a final plat is not required.
Street lighting shall be installed per 38.570, BMC (in regards to completion time for
improvements).
Individual yard lights on private property shall not be used for street lighting.
Section IV. Control of Work
A. General
Record drawings shall be provided to the City for all new and re-constructed lighting systems that
are to be maintained by the City. Cut sheets of all equipment shall be provided with the record
drawings.
For lighting projects in new subdivisions, record drawings shall be provided and a final
inspection done before final plat approval.
For site plans that include lighting projects, record drawings shall be provided and a final
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
inspection done before occupancy approval.
Contractor is required to submit record drawings and equipment cut sheets for any electrical
work that alters an existing lighting system, prior to receiving full payment for project work.
B. Deviation Request
Deviations may be granted by the City Engineer. Appeals to denials of deviation requests shall
be to the Director of Public Works. Refer to Section 38.570 for additional information.
Section V. Utility Clearances
A. Overhead Powerline Clearances
Light standard assembly locations must comply with National Electrical Safety Code (NESC)
Rules regarding clearance requirements between phase conductor and streetlight and between
primary conductor and streetlight.
Light standard assembly locations must comply with the Occupational Safety and Health
Administration (OSHA) 1926.1408 minimum clearance distances to overhead power lines.
The City will not accept work that does not meet these clearance requirements or requires a
qualified worker to maintain the lighting system.
B. Below-grade Utility Clearances
Light standard foundations shall be located to maintain a minimum horizontal clearance of 10 feet
from the edge of foundation to the edge of any water line, sewer line, storm drain line or gas line.
When paralleling water, sewer, storm and gas lines with lighting conduit, a 10-foot horizontal
separation is preferred. Where 10 foot separation is impractical, a minimum of 5-foot horizontal
separation will be allowed.
Section VI. Conduit
A. Plastic Conduit - PVC
All PVC conduits located under roadways, driveways, and other vehicular access areas shall be
schedule 80 type EPC-80-PVC.
Conduits under non-vehicular locations may be schedule 40 type EPC-40-PVC.
PVC conduit shall be manufactured of high-impact PVC, and shall conform to industry standards
and commercial standard CS-207-60 and NEMA TC 2.
All 90-degree conduit bends shall be factory 90-degree elbows that are schedule 80 PVC or PVC
coated GRC.
Field conduit bends may be used for bends that are 60-degrees or less. When bending PVC
conduit in the field, use a heater that is approved by the conduit manufacturer.
Bends in PVC conduit shall be made and conform to all appropriate sections of the National
Electric Code or local codes governing bending radius, and the number of bends allowed as
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
applicable for rigid conduit.
Conduit bends, except factory bends, shall have a radius of not less than six times the inside
diameter of the conduit.
B. Plastic Conduit – HDPE
All HDPE conduit shall be factory lubricated, low friction, high-density conduit constructed of virgin
high density conduit constructed of virgin high-density polyethylene resin. Conduit shall be
capable of being coiled on reels in continuous lengths, transported, stored outdoors, and
subsequently uncoiled for installation, without affecting its properties or performance.
Bored electrical conduit shall be HDPE and installed using trenchless technology of either jacked
conduit or directional boring.
C. Steel Conduit
Steel conduit for exterior, surface mounted, above grade installations shall be Galvanized Rigid
Conduit (GRC). Polyvinyl Chloride coated Galvanized Rigid Conduit (PVC coated GRC) may be
used for below grade installations, encased in concrete and above grade where exposure to water
is imminent.
GRC conduit shall comply with ANSI C80.1 and UL 6.
PVC coated GRC shall comply with NEMA RN 1. Coating thickness shall be a minimum of 0.040
inch (1mm), both inside and out.
D. Conduit Installation
All conduit direct buried in contact with earth shall be PVC, HDPE or PVC coated GRC. PVC
conduit Installation through foundations (other than light standard foundations) shall have
transition to GRC or PVC coated GRC prior to exposure above foundation.
Underground conduit shall have the following minimum diameter (ID) trade size conduit, unless
otherwise approved by the Engineer.
1. Conduit Sleeves Under Roadways: 3 inch minimum
2. Conduit in Typical Trench: 2 inch minimum
3. Conduit from Pull Box / Splice Box to Foundation: 1 inch minimum
4. Conduit to Pathway Luminaires: 3/4 inch minimum
Conduits shall be placed two feet from back of curb.
All existing conduits shall be cleaned with a mandrel or cylindrical wire brush and all conduits
(existing or new) shall be blown out with compressed air, before conductors or signal facilities are
installed.
All empty spare conduits shall be installed with the following:
1. A nylon or polyester pull tape of at least 1250 lbs strength with footage marking tape.
2. For bored conduit installations that require complete intersection rewiring or new
construction, a 12 AWG tracer wire shall be installed across every empty conduit leg, and
conduit plugs shall be installed in all conduits.
3. Pull rope with footage tape, tracer wire, and conduit plugs shall be included in the price of
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
electrical conduit.
When conduit is specified to be installed under existing pavement by directional line boring, the
boring pits shall be kept a minimum of 2 feet clear of the edge of pavement whenever possible.
Conduit installed under pavement, sidewalk, dirt, sod or any condition other than under an existing
roadway shall be installed with not less than 24 inches of cover to the top of the conduit. Under
existing roadway, conduit shall be installed with not less than 30 inches of cover to the top of the
conduit. Conduit installed under railroad tracks shall be installed not be less than 42 inches
below the bottom of the tie to the top of the conduit. [Refer to Figure 1 – Typical Conduit Burial
Standard Detail].
Section VII. Pull Boxes / Splice Boxes
A. General
All pull / splice boxes and covers must be made of polymer concrete with fiberglass
reinforcement with a traffic rating of TIER 22.
Pull / splice boxes shall be labeled "ELECTRIC" on pull / splice boxes containing electrical power
or “LIGHTING” on all pull / splice boxes containing street lighting conductors. The labeling must
be cast into the cover and not a separate independent tag. [Refer to Figure 2 – Typical In-Grade
Pull Box / Splice Box Dimensions Standard Detail]
B. Pull Box / Splice Box Installation
When pull / splice boxes are located behind sidewalk or in non-pavement areas, they shall be
surrounded by a 12 inch wide collar of class B concrete 6 inches deep. [Refer to Figure 3 – Typical
In-Grade Composite Pull Box / Splice Box Detail]
Maximum distance between pull / splice boxes is 200 feet for street and pedestrian lights, and
100 feet for pathway lights.
Street crossings for conduit runs need to have a pull / splice box at each side of the street crossing.
Pull / splice boxes are to be installed at each street corner where conduit takes a 90 degree bend
around the corner of the block.
Provide a Type 1 or Type 2 pull / splice box by each streetlight or pedestrian light with smaller 1
inch diameter conduit allowed going into light base from pull / splice box.
For pathway lights, conduit may be routed in and out of the foundation, with a minimum conduit
size of 1 inch. Pull / splice boxes for pathway lights shall be placed at 90-degree bends around a
corner, and at the minimum spacing listed above.
Box size shall be determined by the diameter of the Largest Trade Size Conduit (LTSC) installed
in the box. For conductors 6 AWG or smaller, the box shall be sized (6) six times LTSC in width
or length dimension. For conductors 4 AWG and larger, the box shall be sized (8) eight ties LTSC
in width or length dimension.
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
For future expansion, empty conduit, with nylon or polyester tape pull tape of at least 1250 lbs
strength with footage marking tape, shall terminate in a pull / splice box. Stub spare conduit(s)
out of the box and cap below grade at 2 feet from the box, in the direction of future expansion.
Label conduit stub out(s) in pull / splice box “for future expansion to the direction of expansion”.
Wire connections in pull / splice boxes should use water-proof, insulated multi-tap connectors, by
Burndy, or Ilsco, or equivalent.
Section VIII. Concrete Foundations
A. Light Standard Foundations
In locations where the roadway is not curbed, and/or in dirt, the top of the foundation shall be six
inches above the grade of the edge of the pavement or as directed by the Engineer. The top of
the foundation shall be finished smooth and have a 3/4 inch chamfered edge. [Refer to Figures
4, 5 and 6 – Typical Light Standard Foundation Electrical Details]
Where caisson foundations are located in the sidewalk, the caisson foundation shall be installed
to 6 inch under finished curb or sidewalk grade or as directed by the Engineer. [Refer to Figure 4
– Typical Light Standard Foundation Electrical Details ]
Where foundations are to be installed in dirt, landscaped areas, or any other situation where the
top of the caisson is not being installed with an existing sidewalk or concrete improvement, the
contractor shall use sono-tube on the top section of the caisson for finished appearance.
A structural engineer licensed in the state of Montana shall determine the foundation size (depth
and diameter) and concrete reinforcement for the specific light standard configuration.
B. Concrete Foundation Pads
All lighting control center cabinets that are to be installed in concrete, shall have either, an
approved anchor bolt template with bolts installed before concrete pour, or upon approval of the
Engineer, be installed using approved concrete drop in style anchors. All lighting control center
cabinets installed in areas other than concrete, shall be installed to their marked grade on a
concrete foundation pad with 24” depth, sized to fit cabinet dimensions with 3 inch minimum to 6
inch maximum offset of concrete on all sides of the enclosure. Provide 3 foot x 3 foot step pad
with a maximum slope of 1:24. [Refer to Figures 7a, 7b, 8 and 9 – Typical Lighting Control Center
Standard Details]
C. Concrete Fill for Pedestal Type Cabinets
All pedestal type cabinets mounted on galvanized strut-channel supports shall have concrete filled
post holes with a minimum depth of 36-inches and minimum diameter of 9-inches. [Refer to Figure
8 – Typical Lighting Control Center Pedestal Standard Detail ]
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Section IX. Wiring
A. General
All wiring shall be copper conductors installed in conduit to meet the National Electric Code.
Minimum size current carrying conductor for exterior installations shall be #10 AWG copper.
Furnish conductors of solid or stranded copper of the gauge shown in the contract.
Insulation for conductors must be Type THW, XHHW, XHHW-2, USE, RHH, RHW, THWN, and
THWN-2. All insulation must be designed for 600 volts and meet NEC requirements.
All wiring shall be pulled into conduit using a nylon or polyester pull tape of at least 1250 lbs
strength with footage marking tape.
Metal Clad cable (MC) or Armored Cable (AC) shall not be allowed in exterior applications.
Exterior lighting shall be powered at 120/240V-1PH-3W unless otherwise noted on the plans.
Wiring color code shall be as follows:
Line 1 = Black
Line 2 = Red
Neutral = White (only required when 120V power is present)
Ground = Green
Section X. Bonding and Grounding
A. General
All PVC or PVC coated GRC conduits from a metered power source shall have a raceway ground
conductor installed with the current carrying conductors, sized to the NEC. Ground conductor
shall have the size increased to match current carrying conductor size increase for voltage drop
purposes.
All light standard foundations for streetlights and pedestrian lights shall have a 5/8 inch diameter
x 8 foot long, copper clad driven ground rod installed in the pull / splice box next to the light
standard. Top of rod shall be a minimum of 4 inches below grade. Exothermic weld or
underground rated lug connect a #6 AWG soft drawn bare copper conductor from rod through 1/2
inch trade size conduit in the foundation to the lug on the pole in the back of the hand hole.
In instances where no dedicated ground rod is present in the pullbox to clamp to the #6 bare
copper conductor, the contractor shall clamp to the light pole foundation rebar cage. In this
situation, the light pole foundation must be in direct contact with the ground (sonotube removed).
Pathway lights shall have the system grounding conductor bonded to the grounding lug inside
each bollard.
All grounding electrodes shall be bonded together per the NEC.
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Section XI. Lighting Control Centers and Metered Pedestals
A. General
All street lighting systems shall be metered separately from other uses, with the exception of
streetlights installed in conjunction with traffic signal poles.
Lighting control centers and metered pedestals shall be located outside of the sight triangle and
within the public right of way or easement at least 50 feet from intersection corners. The location
shall be behind the sidewalk where possible and in the boulevard near the sidewalk when right of
way does not allow for placement behind the sidewalk.
B. Installation
Electric services shall use NEMA Type 3R cabinets with hinged, lockable covers and 3/8” holes
for a padlock.
Services shall be equipped with 3-way switches for hand-off-auto (HOA) operation. Wire photocell
on/off control in the auto position.
Lighting control centers shall house electrically held lighting contactors that are 12-pole with 30
amp contacts rated at 600V, and 120V coils.
Street lighting circuits shall be automatically controlled with turn lock mounting delayed response
photo cells. Lighting control centers shall have a 120V twist-lock receptacle type photoelectric cell
with matching receptacle base attached to the assembly with heavy duty galvanized c-channel
structure using 1 inch galvanized rigid conduit, mounted 8 feet above grade. Orient window of
photocell to face north. Photocell to operate the lighting contactors for on/off control when HOA
is in the auto position.
Meters shall be installed a minimum of 4 feet and maximum of 5 feet above grade to the center of
the meter.
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Section XII. Lighting Design Criteria
This section describes the luminaire selection and lighting layout for each street classification.
Designers are required to submit the following to the City of Bozeman for all street lighting
projects:
Calculation summary (more information can be found in Section XII.D)
Luminaire Submittal Form (found in Appendix A)
A. Lighting Controls
All street and pedestrian lights installed shall have on board dimmers to allow for dimming in the
field after luminaires have been installed. Onboard dimmers will allow for city officials to be able
to dim lights when residents are offended following new installations.
All streetlights shall have and ANSI 7-Pin receptacle to be compatible with future wireless control
systems.
B. Intersections and Crosswalks
The same luminaires are to be used throughout the intersection. When an intersection is between
two different street classifications, the higher street classification target criteria is used throughout
the entire intersection. The recommended streetlight layout for an intersection is also dependent
on whether the street classification calls for continuous or non-continuous lighting.
All traffic signal mounted streetlights shall meet the lighting requirements listed below. The
intersection design shall ensure that the crosswalks are sufficiently lighted to light the vertical
surface (body) of pedestrians in the crosswalk. This may require that additional streetlights be
located before the intersection as shown in the Figures below.
Mid-block crossings and denoted crosswalks shall be lighted. Crosswalks can be denoted by
striping, signage, flashing beacons, etc. Crosswalks are important parts of the streetscape and
an appropriate lighting design will improve the visibility of pedestrians in the crosswalk. The
lighting should be installed between the vehicle and the crosswalk (ie: half to one pole height
before the crosswalk) to ensure that the body of the pedestrian is adequately lighted. If streetlights
are installed above or immediately adjacent to the crosswalk, only the top of the pedestrian’s head
will be lighted making it difficult for motorists to see the pedestrian. Crosswalks and mid-block
crossings shall be lighted to the Vertical Illuminance requirements in the table below. See Section
D for instructions on how to set up a calculation for crosswalks and mid-block crossings.
Figure 1: Streetlight Located Before Crosswalk Figure 2: Streetlight Placement with Respect to Crosswalk
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Table A: Intersection Target Horizontal & Vertical Criteria
Signalized, large intersections
This intersection type applies to:
Arterial/Arterial
Arterial/Collector
For a signalized intersection, with
continuous lighting, the typical streetlight
arrangement is interrupted by placing a
streetlight half to one pole height in front of
the crosswalk. This is called out as “1/2 to
1 pole height before crosswalk”. See the
Crosswalk section for more information.
Additional streetlights should be located
on signal poles if additional lighting is
needed to meet the intersection criteria.
Figure 3: Signalized, Large Intersection
Functional
Classification Adjacent Land Use
Average
Horizontal
Illuminance
(Fc)
Uniformity
Ratio
(Fcavg/Fcmin)
Average
Vertical
Illuminance
(Fc)
Luminaire
Mounting
Height
(feet)
Recommended
Mast Arm
Length (ft)
Distribution Max BUG
Rating
Commercial / Institutional 2.4 6 1.0 35-40 10 Type 2 or 3 3-0-3
Residential / Industrial / Rural 1.7 6 0.8 30-35 10 Type 2 or 3 2-0-2
Commercial / Institutional 2.0 6 1.0 35-40 10 Type 2 or 3 2-0-2
Residential / Industrial / Rural 1.4 6 0.7 30-35 10 Type 2 or 3 2-0-2
Commercial / Institutional 1.9 6 0.8 35-40 10 Type 2 or 3 2-0-2
Residential / Industrial / Rural 1.2 6 0.6 30-35 10 Type 2 or 3 2-0-2
Commercial / Institutional 1.7 8 0.8 30-35 6 Type 2 or 3 2-0-2
Residential / Industrial / Rural 1.1 8 0.5 30-35 6 Type 2 or 3 1-0-2
Commercial / Institutional 1.5 8 0.7 30-35 6 Type 2 or 3 1-0-2
Residential / Industrial / Rural 0.9 8 0.5 30-35 6 Type 2 or 3 1-0-2
Commercial / Institutional 1.3 10 0.6 25-30 6 Type 2 or 3 1-0-1
Residential / Industrial / Rural 0.7 10 0.5 25-30 6 Type 2 or 3 1-0-1
Commercial / Institutional
Residential / Industrial / Rural
Arterial /
Arterial1
Arterial /
Collector1
Arterial /
Local1
Collector /
Collector2
Collector /
Local2
Local / Local
<30mph
Local / Local
>30mph
* A U2 BUG rating is acceptable when using a house side shield?
1. Arterial mid block crossing shall follow the arterial/arterial intersection criteria.
NA
NA
2. Collector mid block crossing shall follow the collector/collector intersection criteria.
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Non-signalized, large intersection
This intersection type applies to:
Arterial/Collector
Arterial/Local
Collector/Collector
The larger street sections should be
continuously lighted through the
intersection. The typical streetlight
arrangement is carried through the
intersection. The streetlights should be
located half to one pole height before the
crosswalk, if it exists.
The smaller cross street should have at
least one light located before the stop bar.
Signalized, small intersection
This intersection type applies to:
Arterial/Local
Collector/Collector
Streetlights should be located half to one
pole height before the crosswalk. This will
light the people within the crosswalk. An
additional streetlight located along the
cross street should be included to better
illuminate the crosswalk if necessary.
Additional streetlights should be located on
signal poles if additional lighting is needed
to meet the intersection criteria.
Non-signalized, small intersection
This intersection type applies to:
Collector/Local
Local/Local
At least one luminaire is to be placed at
each intersection.
Figure 4: Non-Signalized, Large Intersection
Figure 5: Signalized, Small Intersection
Figure 6: Non-Signalized, Small Intersection
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Mid-Block Crosswalks
A streetlight shall be located one half to 1 mounting height in front of the crosswalk on both sides
of the street for all mid-block crossings.
Figure 1: Streetlight Placement with Respect to Mid-Block Crossing
Figure 7: Mid-Block Crossing
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
C. Continuous Lighting on Streets
Provide continuous lighting for all arterial, collector, and local streets as specified in Table A.
Lighting criteria varies for each street classification based on adjacent land use. Due to a higher
pedestrian activity, streets located adjacent to commercial and institutional properties will have a
higher lighting criteria. Commercial and institutional properties include churches, schools, retail
areas, and restaurants. Streets located adjacent to residential, industrial, and rural properties, as
well as office parks have a lower lighting criteria due to lower pedestrian activity. The lighting
criteria and adjacent land use shall be evaluated on a block-by-block basis. Therefore, if a project
is traveling through a residential area and passes by a school, the block that the school is on will
have a higher criteria than the rest of the project. A house-side shield is highly recommended on
all installations and may be needed to meet the required maximum BUG Rating. All streetlights
shall have a U0 uplight rating, unless an external house side shield is being used. When an
external shield is in use, light can be reflected upwards, therefore, when a shield is necessary to
reduce light trespass, a U2 uplight rating is acceptable. Internal house side shields can maintain
a U0 uplight rating and are preferred. All roadway calculations where a house-side shield is
intended on being used shall be calculated with an .ies file that includes the shielding.
Designers should strive to meet the luminaire spacing that will provide the highest quality street
lighting possible, but this is not always feasible. It is necessary to integrate lighting locations to
coordinate with other improvements:
Clearance from driveways (10 feet commercial and 5 feet residential).
Clearance from fire hydrants (5 feet).
Trees (centered in between trees or 10 feet from the tree trunk).
Place poles and luminaires near property lines wherever practical and avoid locations in front of
doorways, windows, and lines of egress. A staggered luminaire arrangement is preferred but is
not always feasible. Single sided arrangements should only be used when necessary.
Table B: New Construction Lighting Design Guidance.
Functional
Classification
Adjacent Land
Use
Average
Luminance
(cd/m2)
Uniformity
Ratio
(Lavg/Lmin)
Luminaire
Mounting
Height (ft)
Arrangement Lumen
Output Range Distribution Max
CCT
Max BUG
Rating
Staggered 11,000 - 14,000 Type 2 or 3 3,000 B2-U0-G2
Single Sided
Staggered 7,000 - 10,000 Type 2 3,000 B1-U0-G2
Single Sided 7,000 - 12,000 Type 2 3,000 B1-U0-G2
Staggered 7,000 - 10,000 Type 2 3,000 B2-U0-G2
Single Sided 7,000 - 12,000 Type 2 3,000 B2-U0-G2
Staggered 3,500 - 5,500 Type 2 2,700 B1-U0-G2
Single Sided 5,000 - 7,500 Type 2 2,700 B1-U0-G2
Staggered 3,500 - 5,000 Type 2 3,000 B1-U0-G1
Single Sided 4,000 - 6,000 Type 2 3,000 B1-U0-G1
Staggered 2,500 - 4,000 Type 2 2,700 B1-U0-G1
Single Sided 3,500 - 4,500 Type 2 2,700 B1-U0-G1
Local -
Continous
Commercial /
Institutional 0.3 10 25-30 Single Sided 3,500 - 4,500 Type 2 3,000 B1-U0-G1
Local Residential /
Industrial / Rural NA 10 25-30 Single Sided 2,500 -4,000 Type 2 2,700 B0-U0-G1
* At time of publication, all Principal Arterial Streets except for Conttonwood Road are owned and maintained by MDT.
Residential /
Industrial / Rural
Commercial /
Institutional
25-30
25-30
0.3
0.5
10
10
0.6Commercial /
Institutional
6
6
30-350.4Residential /
Industrial / Rural 8
* A U2 BUG rating is acceptable when using a house side shield.
Principal
Arterial
Minor Arterial
Collector
Not Recommended 30-350.9Commercial /
Institutional
30-350.6Residential /
Industrial / Rural
30-35
5
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
All new installations and retrofits of streetlights shall conform to the standards set forth in Table
B, based on street classification, adjacent land use, and luminaire arrangement.
D. Calculations
Lighting calculations are required for all street lighting projects for the City of Bozeman.
Calculations shall be done in AGi32, DIALux, Visual, or comparable software, and include the
following calculation grids:
Roadway Luminance
o A calculation grid is required for every lane of traffic and shall be oriented in the
direction of travel spaced 10’ OC along each lane, with two points across each
lane.
o Every section of roadway where criteria changes requires a separate calculation
grid.
Intersection Illuminance
o Intersection calculations shall be done using horizontal illuminance grids that
include the whole intersection, as well as all crosswalks associated with the
intersections. Calculation points shall be placed in a 5’x5’ grid.
Sidewalk Illuminance
o Horizontal sidewalk illuminance grids shall be placed on all sidewalks, spaced
every 5’-10’ OC along the sidewalk with two points across the sidewalk.
Light Trespass Illuminance
o Light trespass grids shall be located 5’ past the edge of ROW, into private property.
Light trespass grids shall be placed 5’ AFF, oriented toward the street with
calculation points every 5’-10’ OC.
o Light trespass calculation grids shall be separated based on adjacent land use. If
the project goes from a residential area to a commercial area, a separate light
trespass calculation grid will be required for each section of the project.
o If a structure is within 5’ from the property line, light trespass grid to be placed on
the structure, 5’ AFF.
o Light trespass values shall not exceed the following:
Residential properties: 0.1Fc Maximum.
If this criteria is not feasible with proper shielding and distribution, a
variance may be considered to allow up to 0.2Fc Maximum light
trespass in residential areas. Designer will be required to submit a
narrative describing the efforts to control light trespass to the City
Engineer.
Commercial and mixed-use residential properties: 0.3Fc Maximum
Crosswalk Vertical Illuminance
o Vertical illuminance grids shall be placed in all crosswalks at 5’ AFF, and oriented
according to Figure 9. Calculation points shall be located along the center line of
each crosswalk, placed every 5’ OC.
Designers shall submit to the City a calculation summary table for each calculation grid and
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
include the average illuminance or luminance, maximum illuminance or luminance, minimum
illuminance or luminance, and Avg:Min ratio. Calculated values may vary from criteria by no more
than 10% above or below.
Calculations shall not include a light loss factor (LFF).
Figure 8: Intersection Calculation Grid Setup
Figure 10: Roadway, Sidewalk, and Light Trespass Calculation Grid Setup
Figure 8: Horizontal Intersection Illuminance Grid Figure 9: Vertical Intersection Illuminance Grid
Figure 10: Calculation Grids for Roadway Luminance, Sidewalk Illuminance, and Light Trespass
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
E. Design Considerations.
In addition to the requirements outlined in Table B, the following layout criteria shall be used:
When a streetlight location falls near an unlit intersection, the light shall be located at
the intersection;
Streetlights shall be located at property lines to the greatest extent possible, but not in
conflict with other utility service providers;
All proposed local streets within the proposed subdivision, having a curve of 300 feet
or longer in length, shall have a streetlight in the middle of the horizontal curve or as
required by the City Engineer;
A streetlight shall be placed at the terminal ends of center median islands having trees
and/or other fixed objects not having a breakaway design for speeds of 25 miles per hour
or greater;
Additional streetlights may be required by the DRC when potential traffic hazards are
identified during plan review; and
Street and pedestrian lighting arrangements with poles aligned on opposite sides of the
street, rather than staggered are allowed.
Mounting heights shall be measured from the grade of the street at the edge of the travelled
way and shall comply with the requirements of Table B.
F. Pedestrian Lighting.
Pedestrian lighting is defined as luminaires mounted between 12ft and 15ft and shall be installed
at 60 feet to 105 feet on center, as appropriate to coordinate with landscape and hardscape
features. Two pedestrian lights shall be installed on opposite sides of the street at all intersections
of pathways and local streets located within the proposed development or along existing streets
or roads abutting the development, unless the pathway intersects the street at a lighted
intersection. Pedestrian lights shall have a lumen output range of 2,000 – 3,500 lumens, and a
maximum B.U.G. rating of B2-U1-G1. Pedestrian lights in special districts, including those along
Main Street and Wilson Ave, will require special approval from a City Engineer. Spacing of
pedestrian lights shall be determined by meeting the illuminance requirements outlined in Table
C.
Table C. Pedestrian Lighting Guidance.
Adjacent Land Use Average Horizontal Illuminance
for Pedestrian Walkways in
Maintained Footcandles
Illuminance Uniformity
Ratio (avg/min)
Commercial or Institutional 0.5 4.0
Residential, Industrial or Rural 0.3 6.0
Source: Roadway Lighting (RP-8), Illuminating Engineering Society of North America.
G. Pathway Lighting.
Pathway lights shall be installed along pathways through parks and other pathways that are
detached from the street. All pathway lights shall comply with City of Bozeman specifications.
Pathway lights shall have a height range of 40 - 48 inches, a lumen output range of 500 - 1,000
lumens, and a maximum wattage of 25 Watts.
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Section XIII. Streetlight Luminaires
A. General
All luminaires shall be light emitting diode (LED).
Color temperature 3000K maximum, per ANSI C78.377-2011 standard.
All luminaires shall be equipped with a surge suppression device with a minimum
immunity level of 10kV.
All luminaires shall have a field adjustable dimming system to allow for onsite dimming
once installed.
Shielding: All luminaires shall have standard house-side shielding options. Front-side
shielding may also be required to control light trespass across the street. Front-side
shields may be custom, but manufacturer standard shielding is preferred.
New light installations will be evaluated by the City of Bozeman during the required 2-
year warranty period immediately following project acceptance. The City may require
the developer to modify light installations through shielding or dimming to get the
desired light distribution.
The contractor may be required to provide house side light shields to the City of
Bozeman for each new luminaire as a condition of project acceptance.
All luminaires shall have a minimum ingress protection (IP) rating of IP66, and shall be
UL/ETL listed for wet locations.
All luminaires shall be equipped with a 0-10V or DALI dimming driver, capable of
receiving input line voltage 120V-277V. Driver shall comply with Federal
Communication Commission (FCC) 47 Code of Federal Regulations (CFR) part 15
non-consumer radio frequency interference (RFI) and/or electromagnetic interference
(EMI) standards. Minimum power factor (PF) shall be no less than 0.9 at full input
power. Maximum total harmonic distortion (THD) shall be no greater than 20 percent
at full input power.
A minimum 10 year warranty is required for all parts, materials, and shipping required
to repair or replace luminaire.
All luminaires are to be equipped with an ANSI C136.41 7-pin receptacle. Shorting
caps are to be installed on each luminaire.
Luminaires are to have a Type II distribution. Type III distribution allowed on Principal
Arterials and Large Signalized Intersections.
Access to all internal parts requiring replacement shall not require tools (i.e., “tool-less
entry”).
Luminaire shall be tested in accordance with IES LM79 and TM21 certifying
photometric performance and rated life, respectively. LM79 (performance) and TM21
(predicted life) testing shall both be for the same luminaire’s operating drive current as
specified.
Luminaires shall have a minimum L70 live of 100,000 hours based on IES TM21
testing.
Luminaire system efficacy shall be no less than 80 lumens per input watt.
Luminaire shall have an external label per ANSI C136.15 and internal label per ANSI
C136.22.
Luminaires shall be equipped with internal leveling bubble.
Breakaway connections using sheer bolts must have a skirt to protect the bolts.
Luminaires shall be powder coat finished black or powder coat finished to match pole,
unless installed on a local street, then either dark brown or hunter green.
Luminaire distribution shall be equal or less than the Illuminating Engineering Society
of North America’s (IES) TM 15-11 Backlight, Uplight, and Glare (BUG) ratings as
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
specified in Table B.
B. Installation
Luminaires shall be mounted in accordance with the manufacturer’s specifications.
Plumb or level all elements, symmetrically arrange, and securely assemble. Conceal all
conductors in the poles and assembly.
Luminaires shall have an adjustable slipfitter-type mounting system for the installation on 1.25
inch (1.66 inch o.d.) to 2 inch (2.375 inch o.d.) outside diameter pipe tenons. Slipfitter shall consist
of a two-piece clamp and four 9/16 inch hex bolts. Slipfitter shall allow for a vertical tilt adjustment
of +/- 5 percent in order to mount plumb for a U0 rating.
C. Approved Manufacturers – Cobrahead Style [Refer to Figure 10 – Typical
Street Light Standard Detail]
GE Evolve LED Cobrahead
Cree XSP (only to be used with a House-Side Shield and distribution Type II Long)
Lumec Roadfocus
D. Approved Manufacturers – Bell Style [Refer to Figure 10 – Typical Streetlight
Standard Detail]
Lumec Domus
Architectural Area Lighting Universe
Or Pre-Approved Equal
Section XIV. Pedestrian Luminaires
A. General
All luminaires shall be light emitting diode (LED).
Color temperature maximum 3000K, per ANSI C78.377-2011 standard.
All luminaires shall be equipped with a surge suppression device with a minimum
immunity level of 10kV.
All luminaires shall be equipped with a 0-10V dimming driver, capable of receiving input
line voltage 120V-277V. Driver shall comply with Federal Communication Commission
(FCC) 47 Code of Federal Regulations (CFR) part 15 non-consumer radio frequency
interference (RFI) and/or electromagnetic interference (EMI) standards. Minimum
power factor (PF) shall be no less than 0.9 at full input power. Maximum total harmonic
distortion (THD) shall be no greater than 20 percent at full input power.
A minimum 10 year warranty is required for all parts, materials, and shipping required
to repair or replace luminaire.
All luminaires are to be equipped with an ANSI C136.41 7-pin receptacle. Shorting
caps are to be installed on each luminaire.
Luminaires are to have either a Type III or Type V distribution. Type V distributions will
be considered for special use through DRC review.
Access to all internal parts requiring replacement shall not require tools (i.e., “tool-less
entry”).
Luminaire shall be tested in accordance with IES LM79 and TM21 certifying
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
photometric performance and rated life, respectively. LM79 (performance) and TM21
(predicted life) testing shall both be for the same luminaire’s operating drive current as
specified.
Internal house-side shield must be available.
Luminaire system efficacy shall be no less than 60 lumens per input watt.
Luminaire shall have an external label per ANSI C136.15 and internal label per ANSI
C136.22.
Luminaires shall be powder coat finished black or powder coat finished to match pole,
unless installed on a local street, then either dark brown or hunter green.
Luminaire distribution shall be equal or less than the Illuminating Engineering Society
of North America’s (IES) TM 15-11 Backlight, Uplight, and Glare (BUG) rating of B2
U1 G1
For applications approved for Type V distribution, the Backlight rating shall not
apply.
B. Installation
Luminaires shall be mounted in accordance with the manufacturer’s specifications.
Plumb or level all elements, symmetrically arrange, and securely assemble. Conceal all
conductors in the poles and assembly.
C. Approved Products – Traditional Post-top Style [Refer to Figure 11 – Typical
Post-Top Pedestrian Light Standard Detail]
Sternberg Euro
Architectural Area Lighting Providence
Or approved equal
D. Approved Products – Bell Style [Refer to Figure 12 – Typical Arm-Mount
Pedestrian Light Standard Detail]
Lumec Domus
Architectural Area Lighting Universe
Or approved equal
Section XV. Pathway Luminaires
A. General
All luminaires shall be light emitting diode (LED).
Color temperature maximum 3000K, per ANSI C78.377-2011 standard, +/- 275K.
All luminaires shall be equipped with a surge suppression device with a minimum
immunity level of 10kV.
All luminaires shall be equipped with a 0-10V dimming or DALI driver, capable of
receiving input line voltage 120V-277V. Driver shall comply with Federal
Communication Commission (FCC) 47 Code of Federal Regulations (CFR) part 15
non-consumer radio frequency interference (RFI) and/or electromagnetic interference
(EMI) standards. Minimum power factor (PF) shall be 0.9 at full input power. Maximum
total harmonic distortion (THD) shall be 20 percent at full input power.
A minimum 10 year warranty is required for all parts, materials, and shipping required
to repair or replace luminaire.
All luminaires are to be equipped with an ANSI C136.41 7-pin receptacle. For
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
luminaires that are not supplied with integral 7-pin receptacles, provide the 7-pin
receptacle in pole cap on the top of the pole. Shorting caps are to be installed on each
luminaire.
Luminaires are to have either a Type III or Type V distribution. Type V distributions will
be considered for special use through DRC review.
Luminaire shall be tested in accordance with IES LM79 and TM21 certifying
photometric performance and rated life, respectively. LM79 (performance) and TM21
(predicted life) testing shall both be for the same luminaire’s operating drive current as
specified.
Luminaire system efficacy shall be no less than 30 lumens per input watt.
Luminaires shall be powder coat finished black.
Vandal proof. Not flat heads, rounded heads.
Concrete base, no direct burial
Luminaire distribution shall be equal or less than the Illuminating Engineering Society
of North America’s (IES) TM 15-11 Backlight, Uplight, and Glare (BUG) ratings as
follows:
B2 U1 G1
For applications approved for Type V distribution, the Backlight rating shall not
apply.
B. Installation
Luminaires shall be mounted in accordance with the manufacturer’s specifications.
Plumb or level all elements, symmetrically arrange, and securely assemble. Conceal all
conductors in the assembly. [Refer to Figure 13 – Typical Pathway Light Standard Detail]
C. Approved Products
Lithonia Lighting KBR8 LED Bollard
Lithonia Lighting D-Series LED Bollard
Or approved equal
Section XVI. Poles.
A. General
Unless specifically approved by the City Commission, the use of “Montana Angle”, “Budget
Angle”, or similar style streetlight poles is prohibited.
All poles, mast arms, and luminaires for streetlights and signal poles shall be round, tapered
steel with galvanized and painted finish.
Poles for pedestrian lights shall be round, non-tapered steel, with optional decorative fluting, and
galvanized and painted finish.
Unless a variance is granted, all future ARTERIAL AND COLLECTOR street and signal light
poles shall be “Hunter Green” (RAL#6005), Moss Green, or similar in color, excepting that all
future street and signal light poles in the Downtown Business District and North 7th Avenue TIF
District shall be black, and further excepting that entryway streets into Montana State University
(i.e. S. 8th Avenue, College Street, Kagy Boulevard, and S. 11th Avenue) may be dark Bobcat
Blue.
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
The height of streetlight poles shall be determined based upon the lumen output and
application. Refer to Lighting Design Criteria.
Streetlight luminaires shall have a mast arm of 6 feet for local and collector streets, or 10 feet for
principal and minor arterials.
All streetlight poles shall be installed on a concrete foundation with the appropriate base for
the application. [Refer to Figure 9 – Typical Streetlight Standard Details]
All poles, foundations, and breakaway bases shall meet the criteria set forth in the AASHTO
publication Standard Specifications for Structural Supports for Highway Signs, Luminaires, and
Traffic Signals.
B. Installation
Streetlight poles shall be placed typically at five feet from back of curb.
Streetlight standards, pedestrian light standards and pathway lights shall have an access panel
and cover near base for access to wiring, fusible, in-line, water tight, breakaway connectors on
wiring in pole hand hole area such as Bussman type water tight fuse holders. [Refer to Figures
14, 15 and 16 – Typical Pole Base Standard Details]
Section XVII. Pole bases
A. General
Unless otherwise protected, a breakaway base should be provided for all streetlight standards
within the clear zone along rural and high-speed urban highways, except where located within 1.5
times pole height from a bus stop. Non-breakaway bases shall be used for all pedestrian lights
and pathway lights.
B. Breakaway Bolt Couplings.
Breakaway bolt couplings are aluminum connectors or sleeves that are designed to shear when
the pole is hit. The bottom of the coupling is threaded onto the foundation anchor bolts, and the
light standard is attached to the top of the coupling. Four couplings are used with each light
standard. Where breakaway supports are required, use the breakaway bolt coupling unless it will
not function with the approved light standard. [Refer to Figure 14 – Typical Breakaway Bolt
Coupling Standard Details]
C. Frangible Transformer Base.
The frangible transformer base consists of a cast aluminum apron between the concrete
foundation and the base of the pole. It is designed to deform and breakaway when hit by a vehicle
bumper. Use the frangible transfer base where a breakaway base is justified but breakaway bolt
couplings cannot be used. [Refer to Figure 15 – Typical Frangible Transformer Base Detail]
D. Non-Breakaway Anchor Base.
A non-breakaway anchor base consists primarily of a metal plate that is welded to the bottom of
the light standard. The plate allows the light standard to be bolted directly to the foundation without
an intermediate breakaway device. It does not meet AASHTO breakaway base criteria. [Refer to
Figure 16 – Typical Non-Breakaway Pole Base Detail]
City of Bozeman
Standard Specifications for Lighting Materials and Installation
Revision March 2020
Section XVIII. Submittal Requirements
A. General
Plan sheets showing pole locations, conduit locations, pull / splice box locations, and
meter locations are required.
For Street Lighting submittals, provide luminaire cutsheets showing compliance with
Table 1. New Construction Lighting Design Guidance and Section XIII. Streetlight
Luminaires,
For Pedestrian Lighting submittals, provide a Photometric Plan for new installations
showing compliance with Table 3. Pedestrian Lighting Guidance. Also provide luminaire
cutsheets showing compliance with Section XIV. Pedestrian Luminaires.
For Pathway Lighting submittals, provide luminaire cutsheets showing compliance with
Section XII.J. Lighting Design Criteria – Pathway Lighting, and Section XV. Pathway
Luminaires.
Details of point of service, lighting control center, electrical one-line diagrams, pole
foundations, poles, and luminaires are required.
Prior to construction, submit shop drawings (cut sheets) for all material and equipment.
Lighting calculations showing roadway luminance, intersection illuminance, sidewalk
illuminance, and light trespass.
Luminaire Manufacturer & Catalog
Number
Principal Arterial Minor Arterial Collector
Local (Commercial, Institutional)
Adjacent Land Use Commercial, Institutional Residentail, Industrial, Rural
Luminaire Characteristics Initial Luminaire Lumen
Output = System Wattage =Luminaire Efficacy
(lm/W) =
Correlated Color Temperature (CCT)
Color Rendering Index (CRI)
BUG Rating (per IES TM-15) Backlight = Uplight = Glare =
IES Photometric Data in .ies Format Yes No Other
LED Retrofit Luminaire Yes No
0-10V Dimmable Driver Yes No
Field Dimmable Yes No
Exterior Label (per ANSI C136.15) &
Interior Label (per ANSI C136.22) Yes No
Tool-Less Entry Yes No
Luminaire Housing Finish
Rated Life (IES TM-21)
Ambient Temperature Range Minimum Temperature= Maximum Temperature=
Vibration Rating (ANSI C136.31)
UL Listing Wet Location Damp Location IP Rating =
Passive Cooling System Yes No
LED Compatible 7-pin Receptacle (ANSI
C136.41) Yes No Control Module
Internal Wiring and Quick Disconnects
Operating Voltage Voltage =
Power Factor
Total Harmonic Distortion
Surge Protection (IEEE C62.41.2)
Warranty Period
Warranty Start Date
Other Submittals =
=
=
=
Frequency (Hz) =
=
=
=
=
Roadway Luminaire Submittal Form
=
Street Classification
=
=
=
=
Local (Residentail, Industrial, Rural)
Luminaire Manufacturer & Catalog
Number
Adjacent Land Use Commercial, Institutional Residentail, Industrial, Rural
Path or Sidewalk Lighting Path Sidewalk
Luminaire Characteristics Initial Luminaire Lumen
Output = System Wattage =Luminaire Efficacy
(lm/W) =
Correlated Color Temperature (CCT)
Color Rendering Index (CRI)
BUG Rating (per IES TM-15) Backlight = Uplight = Glare =
IES Photometric Data in .ies Format Yes No Other
0-10V Dimmable Driver Yes No
Field Dimmable Yes No
LED Retrofit Luminaire Yes No
Exterior Label (per ANSI C136.15) &
Interior Label (per ANSI C136.22) Yes No
Luminaire Housing Finish
Rated Life (IES TM-21)
Ambient Temperature Range Minimum Temperature= Maximum Temperature=
Vibration Rating (ANSI C136.31)
UL Listing Wet Location Damp Location IP Rating =
LED Compatible 7-pin Receptacle (ANSI
C136.41) Yes No Control Module
Internal Wiring and Quick Disconnects
Operating Voltage Voltage =
Power Factor
Total Harmonic Distortion
Warranty Period
Warranty Start Date
Other Submittals
=
=
=
=
Frequency (Hz) =
=
=
=
=
=
=
=
Pedestrian Luminaire Submittal Form
=
BREAKAWAY
BOLT COUPLING
(ONE OF FOUR)
BOLT
COVER
3/4" BEVEL ON ALL EXPOSED EDGES
TYPICAL BREAKAWAY BASE DETAIL
LIGHT STANDARD FOUNDATION
FOR USE WITHING CLEAR ZONE OR UNPROTECTED INSTALLATIONS.
ANCHOR
BOLT
SPACING
VARIES
1-1/2" PVC CONDUIT STUB
2'-0" (MIN.)2'-0" (MIN.)6"
ANCHOR BASE
HAND HOLE AND COVER. LOCATE
GROUND LUG OPPOSITE HAND HOLE
AND AT SAME LEVEL
ANCHOR BOLT HARDWARE AND
TORQUE PER MANUFACTURER
SPECIFICATIONS.
SPACE CONFORMING TO
MANUFACTURER RECOMMENDATIONS
1" MAXIMUM
7"6"
4"
BREAKAWAY, WATERPROOF, IN-LINE
FUSE HOLDER AND FUSE FOR EACH HOT
AND A BREAKAWAY, WATERPROOF
CONNECTOR ON NEUTRAL (IF REQUIRED)
24"-30"
℄
BOND ONE #6 SOFT DRAWN BARE
COPPER GROUND WIRE AT GROUNDING
LUG IN HAND HOLE AND EXOTHERMIC
WELD TO GROUND ROD IN PULL BOX.
NOTES
1.LIGHT STANDARD FOUNDATIONS MAY BE PRECAST CONCRETE OR CAST-IN-PLACE CONCRETE.
2.ALL CONDUCTORS SHALL BE SIZED IN CONFORMANCE WITH N.E.C. REQUIREMENTS IMSA 19-1 3
CONDUCTOR #14 AWG MINIMUM
NUT COVERS
Scale:
Date:
CITY OF BOZEMAN
STANDARD DRAWING FIGURE 14TYPICAL POLE BASE
STANDARD DETAILS
N.T.S.
2020-04-07
Page 1
City of Bozeman – Street Lighting Method of Measurement
Introduction
Street lighting luminance measurements are best taken on nights with clear skies, dry pavement
and in areas with little to no light contribution from adjacent properties. Preliminary luminance
measurements may be taken using OpticaLight, a luminance photo-mapping application on an
iPad or iPhone. The recommended distance for taking luminance measurements with the
OpticaLight App is 20-ft to 30-ft from the measurement point. The technician performing the
luminance measurements shall complete the Street Lighting Measurement Form to record the
measured street luminance values and the factors that may affect the lighting measurements. If
the measurements from OpticaLight result in an average luminance that is below the acceptable
tolerance from the luminance criteria, luminance measurements shall be re-taken using a
calibrated luminance meter with a 1-degree or 1/3-degree measuring angle and +/- 2% accuracy.
Street Lighting Method of Measurement
1. Intent: There are many factors that can lead to differences between calculated street
luminance and street luminance measured in the field. The intent of this report is to provide
guidance for City of Bozeman field technicians to measure the luminance of street lighting
installations to compare with luminance criteria. By first understanding the many factors that
affect street luminance conditions and differences with calculated street luminance,
technicians will be able to:
a. Determine which factors can be avoided by following these recommended methods;
b. Understand which factors can be accounted for and considered as reasonable
variations; and
c. Identify which factors may need further investigation to troubleshoot any issues that
need to be addressed in order to bring a non-compliant street lighting installation into
compliance.
2. Measured vs. Calculated Street Luminance: The following factors affect the measurement
of street luminance to some degree. Some factors can have a significant impact on the
luminance and perceived brightness of the street surface, while other factors have a minimal
effect.
a. Pavement Conditions: The street surface material, age and condition affects the
reflectance, and therefore, the luminance and perceived brightness of the street
surface.
i. Type of Pavement: The Illuminating Engineering Society’s Recommended
Practice for Roadway Lighting (RP-8-14) defines four pavement types (R1 –
R4) that have different reflectance properties. The most common pavement
types used within the United States are types R1 (typical concrete) and R3
(typical asphalt).
1. R1: Mostly diffuse reflectance properties characteristic of Portland
cement or asphalt surface with a minimum of 15% of the aggregates
composed of artificial brightener aggregates.
City of Bozeman
Street Lighting Method of Measurement
Page 2
2. R2: A combination of diffuse and specular reflectance characteristics of
asphalt surfaces with aggregate composed of a minimum of 60% gravel
of size greater than 10 mm. Also asphalt surfaces composed of 10% -
15% artificial brightener in aggregate mix.
3. R3: Slightly specular reflectance typical of asphalt surfaces with dark
aggregates, rough texture and some months of use. This surface is
common in the United States.
4. R4: Mostly specular surface typical of very smooth asphalt texture.
ii. Age of Pavement: As pavement ages, the reflectance properties also change,
particularly with asphalt pavement. Pavement reflectance can be measured
using a standard 18% reflectance photo-gray card.
1. Concrete (type R1): The reflectance properties of concrete pavement
are much more stable throughout the life of the pavement than asphalt.
2. Asphalt (type R3): Fresh, newly laid asphalt is very dark. Over a period
of 6 - 12 months from laying new asphalt, the pavement lightens and
eventually stabilizes to be a more consistent reflectance. When
measuring luminance of an asphalt street, the pavement reflectance
should be measured by comparing the luminance of a standard 18%
reflectance photo-gray card with the luminance of the pavement, using
the following equation:
𝑅𝑅𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝= 𝐿𝐿𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝 × 𝑅𝑅𝑔𝑔𝑔𝑔𝑝𝑝𝑔𝑔 𝑐𝑐𝑝𝑝𝑔𝑔𝑐𝑐𝐿𝐿𝑔𝑔𝑔𝑔𝑝𝑝𝑔𝑔 𝑐𝑐𝑝𝑝𝑔𝑔𝑐𝑐
𝑅𝑅𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝=𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑜𝑜𝑅𝑅 𝑃𝑃𝑅𝑅𝑃𝑃𝑅𝑅𝑃𝑃𝑅𝑅𝑅𝑅𝑅𝑅 𝑅𝑅𝑔𝑔𝑔𝑔𝑝𝑝𝑔𝑔 𝑐𝑐𝑝𝑝𝑔𝑔𝑐𝑐=𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑜𝑜𝑅𝑅 𝐺𝐺𝐺𝐺𝑅𝑅𝐺𝐺 𝐶𝐶𝑅𝑅𝐺𝐺𝐶𝐶=0.18 𝐿𝐿𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝𝑝=𝐿𝐿𝐿𝐿𝑃𝑃𝐿𝐿𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑜𝑜𝑅𝑅 𝑃𝑃𝑅𝑅𝑃𝑃𝑅𝑅𝑃𝑃𝑅𝑅𝑅𝑅𝑅𝑅 𝐿𝐿𝑔𝑔𝑔𝑔𝑝𝑝𝑔𝑔 𝑐𝑐𝑝𝑝𝑔𝑔𝑐𝑐=𝐿𝐿𝐿𝐿𝑃𝑃𝐿𝐿𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅 𝑜𝑜𝑅𝑅 𝐺𝐺𝐺𝐺𝑅𝑅𝐺𝐺 𝐶𝐶𝑅𝑅𝐺𝐺𝐶𝐶
When measuring the pavement reflectance, the measurement of the
pavement luminance and gray card luminance should be taken with
the meter aimed at the same point, moving the photo-gray card
instead of moving the meter. Moving the meter to aim at a different
point may result in a different light level at the two points, introducing
error into this measurement.
iii. Wet Pavement: When pavement is wet, the street surface becomes more
specular, affecting the reflectance and luminance of the street. Luminance
measurements should not be taken when the pavement is wet.
iv. Snow: When there is snow on the street, luminance and brightness of the street
is significantly increased. Luminance measurements should not be taken when
there is snow on the streets.
City of Bozeman
Street Lighting Method of Measurement
Page 3
b. Atmospheric Conditions:
i. Ambient Temperature: At higher ambient temperatures, electronic components
operate at a lower efficiency, resulting in a reduction in lumen output from
LEDs. At lower ambient temperatures, the electronic components operate at a
higher efficiency, increasing the lumen output from LEDs. The effect of
temperature will vary depending on the luminaire’s thermal management
design.
ii. Cloudy Sky: Clouds increase the reflection of light pollution back to the ground.
Particularly when the ground is covered with snow and the sky is overcast,
there is more light contribution from sky glow than under clear sky conditions.
Under cloudy sky conditions, luminance measurement shall be taken both with
lights off and lights on to determine the contribution from reflected sky glow.
iii. Humidity and Airborne Particulates: In high humidity or poor air quality
conditions, more light is scattered in the air before reaching the roadway
surface. If the effect of light scattering in the air is visible, luminance
measurements should not be taken.
c. Ambient Lighting Conditions:
i. Twilight: After sunset and before sunrise, is the
period of twilight when the skylight fades into
darkness. Twilight has three stages, civil twilight,
nautical twilight and astronomic twilight. Street
lighting measurements shall not be taken until
Nautical Twilight to eliminate light contribution
from the sky. Nautical Twilight can be determined
using the Sunrise Sunset Calendar website:
http://www.sunrisesunset.com/USA/Montana.asp
1. Civil Twilight: During civil twilight, electric
lighting is not needed to clearly distinguish
terrestrial objects. During clear evening's
civil twilight, horizontal illuminance
decreases from approximately 45
footcandles to 0.2 footcandles.
2. Nautical Twilight: During nautical twilight,
the horizon is still clearly distinguishable.
During a clear evening's nautical twilight,
horizontal illuminance decreases from
approximately 0.2 footcandles to 0.0008
footcandles.
3. Astronomical Twilight: By the end of astronomical twilight, the sky is
dark enough for all astronomical observations.
ii. Moonlight: On a clear night, full moonlight produces 0.01 footcandles, and a
quarter moon produces 0.001 footcandles. The contribution, even from full
Excerpt from the Sunrise
Sunset Calendar website
City of Bozeman
Street Lighting Method of Measurement
Page 4
moonlight, is generally not enough to effect the lighting measurement.
However, technicians should note the phase of the moon and moonrise in the
luminance measurement report. If measurements are taken during a full moon,
the technician may also take luminance measurements with the lights turned
off to establish the contribution from moonlight.
iii. Light Spill from Adjacent Properties: Light contribution from adjacent properties
may be significant, and should be accounted for by technicians when
measuring street luminance. At sites where light spill from adjacent properties
may affect street luminance measurements, technicians should measure the
street luminance both with the streetlights turned off, and again with streetlights
turned on.
d. Electrical / Utility Conditions: Voltage supplied can affect the lumen output of a
luminaire. Lower voltage may result in reduced lumen output and higher voltage may
result in increased lumen output. Some variation in voltage is expected, but should not
exceed +/- 5% from the design voltage at the luminaire. The following factors may
affect the voltage supplied to a luminaire:
i. Wire Sizing: Voltage drop occurs over distance of electrical wiring, and is a
function of the wire type, wire size, length of wire, ampacity of the electrical
load and the supply voltage. Larger gauge wire has less voltage drop per linear
foot than smaller gauge wire. For LED street lighting retrofit projects, the
electrical load is most often being reduced from the original load. Since the
existing wire was engineered for a higher load, it is typically over-sized for the
new lower LED loads and voltage drop is not usually a concern.
ii. Wire Type: Copper wire has the best conductivity and longevity, maintaining
its conductivity over time. Aluminum wire is more susceptible to corrosion and
thermal expansion and contraction, which can affect the wiring connections
and conductivity over time. In older street lighting installations, the age of the
wiring may contribute to inadequate operating conditions.
iii. Conduit Type: For in-grade electrical wiring installations, PVC and HDPE
conduit provides the best long-term protection of the wiring. While most new
street lighting installations use these conduit types, some older street lighting
may have been installed with galvanized rigid conduit (GRC) or even with direct
bury cable (DBC) with no conduit protection. GRC and DBC installations can
corrode or degrade over time, reducing the functional life of the wiring, which
may contribute to inadequate operating conditions.
iv. Utility Supply Voltage: Voltage supplied by the utility to the Lighting Control
Center may vary from the design voltage. If the voltage at the Lighting Control
Center is more than 2% below the design voltage, the City should contact the
electrical utility to help determine the cause.
City of Bozeman
Street Lighting Method of Measurement
Page 5
e. Luminaire Manufacturing
i. Manufacturing Quality: Optics and light output may vary between the sample
luminaire that was used to create the photometry used in the lighting
calculations and the actual luminaires installed in the field. While normal
tolerances in the manufacturing process should be expected, the quality of
manufacturing process may result in unacceptable variation from the
specifications.
ii. Luminaire Specifications: Luminaires have multiple options for different optical
distributions and lumen outputs. If the installed luminaires do not match the
specified and calculated luminaires, the measured light levels may vary
significantly from designed levels.
iii. Thermal Management: Heat from LEDs is emitted back through the circuit
board that the LED is mounted to. If this heat is not adequately dispersed away
from the circuit board, and the LEDs overheat, the light output degrades much
faster.
iv. LED Driver: The LED driver regulates the electrical voltage and current that is
delivered to the LEDs. The electrical current is typically expressed in milliamps
(mA). LEDs can be driven at multiple drive currents, with lower drive currents
emitting less light and higher drive currents emitting more light. If the light
output is too low, a higher drive current will increase the light output of the
luminaire. Some drivers are designed with field selectable drive current that
may be set to a higher drive current without replacing the driver.
f. Measuring Equipment
i. Calibrated Luminance Meter: Calibrated luminance meters like the Konica
Minolta LS-110 or LS-160 provide high accuracy luminance measurements at
low light levels that are typical in street lighting applications. Luminance values
can be measured at any distance.
ii. OpticaLight iPhone/iPad Application: The OpticaLight iPhone/iPad application
provides a less expensive option for measuring luminance. Luminance
measurement from this application tend to be lower than the LS-110 luminance
meter by 15% - 20% on average. The accuracy improves when measurements
are taken at a distance of 20-ft to 30-ft from the measurement point. When
there is high contrast, measurements may need to be taken at a closer range
to reduce the area within the view, thereby reducing the contrast within the
view.
g. Construction
i. Light Pole Locations: As-built light pole locations may vary from designed
locations to avoid conflicts that were unforeseen during the design phases.
Light pole locations that vary significantly from the design may adversely
impact the measured light levels on the street.
City of Bozeman
Street Lighting Method of Measurement
Page 6
ii. Light Pole Geometry: The pole height and mast arm length should match the
design specifications. Variations in height or location of the luminaire may
affect the measured light levels on the street.
iii. Luminaire Orientation & Positioning: Luminaires may be installed with a tilt or
twist, resulting in the luminaire not being level, changing the light distribution
from the intended design.
h. Light Loss Factors
Roadway lighting calculations are performed using light loss factors that reduce the
lumen output of luminaires to ensure that adequate luminance is provided through the
life of the lighting system as the light source ages and dirt accumulates on the
luminaire. A lighting calculation using light loss factors results in the “maintained
luminance” of the street. When a new lighting installation is being measured, these
light loss factors should be close to 1.0, resulting in “initial luminance” of the street.
i. Lamp Lumen Depreciation (LLD): For maintained lighting calculations, the
Lamp Lumen Depreciation (LLD) factor for LED luminaires shall be 0.9.
ii. Luminaire Dirt Depreciation (LDD): For maintained lighting calculations, the
Luminaire Dirt Depreciation (LDD) factor for LED luminaires shall be 0.9.
iii. Total Light Loss Factor (LLF): Multiplying the LLD(0.9) x LDD(0.9) results in a
total Light Loss Factor (LLF) of 0.81.
City of Bozeman
Street Lighting Method of Measurement
Page 7
References
European Road Lighting Technologies - Luminance Design and Pavement Reflection
Factors
http://international.fhwa.dot.gov/euroroadlighting/04.cfm
“Furthermore, results of studies have shown that, in the case of porous asphalts, it typically takes
between 6 months and a year for the pavement to stabilize in order to obtain reliable R-values.”
“In an additional conversation with Werner Riemenschneider, however, he clarified that after the
pavement had aged for 6 to 12 months, the Swiss typically found that the measured average
values were within 15 percent of the average design value, usually on the high side.”
“In the good cases the Belgians noted discrepancies of less than 10 percent, when comparing
measured luminance levels against calculated levels for pavements, where the reflection
characteristics have been determined.”
“In Switzerland, experts emphasized the importance of dry roadways when conducting field
measurements. There are, however, only a couple of summer months during which pavements
are dry enough to be measured. In addition, the team heard warnings about dew points and
pavement ages. It was noted that, during observations in cold weather (typically October through
December), with a clear sky, when conditions were under the dew point, a water film could
suddenly appear on the roadway. This film could provide a reflectance differential of 200 percent.
Given these difficulties and variations in pavement reflection characteristics, the Swiss typically
verify lighting installations with incident light measurements.”
PNNL – Lumen Maintenance and Light Loss Factors
http://www.pnnl.gov/main/publications/external/technical_reports/PNNL-22727.pdf
Twilight Envelope (3.2 lux) as a Visibility Criterion
http://www.visualexpert.com/Resources/twilightcriterion.html
During civil twilight, approximately the first half hour after sunset, ground illuminance in good
weather declines by a factor of about 100, from roughly 330 lux to 3.2 lux.
American Meteorological Society
Civil Twilight: http://glossary.ametsoc.org/wiki/Civil_twilight
During a clear evening's civil twilight, horizontal illuminance decreases from ∼585–410 lux to ∼3.5–2 lux.
Nautical Twilight: http://glossary.ametsoc.org/wiki/Nautical_twilight
During a clear evening's nautical twilight, horizontal illuminance decreases from ∼3.5–2 lux to ∼0.008 lux.
Astronomical Twilight: http://glossary.ametsoc.org/wiki/Astronomical_twilight
During a clear evening's astronomical twilight, horizontal illuminance due to scattered sunlight
decreases from ∼0.008 lux to ∼6 × 10-4 lux.
Sunrise/Sunset Calendar
http://www.sunrisesunset.com/USA/Montana.asp
This website provides calendars with sunrise/sunset information for specific locations, with
appropriate adjustments for latitude, longitude and time zone. Information display options include
City of Bozeman
Street Lighting Method of Measurement
Page 8
sunrise, sunset, moon phase, moonrise, moonset, civil twilight, nautical twilight and astronomical
twilight.
City of Bozeman – Street Lighting Method of Measurement
Step-by-Step Street Luminance Measurement Method
1. Schedule and Prepare for Site Visit:
a. Determine Measurement Start Time:
Street lighting measurements shall not be taken
until Nautical Twilight to eliminate light contribution
from the sky. Nautical Twilight can be determined
using the Sunrise Sunset Calendar website:
http://www.sunrisesunset.com/USA/Montana.asp
b. Arrange Traffic Control (if necessary)
c. Resources & Equipment Needed
i. Personal Protective Equipment (PPE)
1. High Visibility Vest
2. High Visibility Pants or Gators
3. Hard Hat
ii. Measuring Wheel or 200-ft Measuring Tape
iii. Luminance Measurement Equipment
1. iPad/iPhone with OpticaLight App, or
2. Calibrated Luminance Meter
iv. Photo-gray Card to measure pavement
reflectance
v. Camera
vi. Street Lighting Measurement Form (Excel
Spreadsheet) to record conditions taken in
steps 2-4 below.
2. Record Field Conditions:
a. Pavement Type (Concrete, Asphalt-New, or
Asphalt-Aged)
b. Pavement Conditions (dry, wet, or snow packed):
Only measure when pavement is dry
c. Sky Conditions (clear, partly cloudy, overcast)
d. Light spill from adjacent properties
3. Layout & Mark Measurement Points:
a. Locate points in the center of each lane spaced at
1/4 of the street light pole spacing
4. Measured and Record Street Luminance:
a. Select Luminance Measurement Equipment
(OpticaLight or Calibrated Luminance Meter)
b. Measure Pavement Reflectance
i. Measure Gray Card Luminance
ii. Measure Pavement Luminance at same
location
c. Measure Street Lighting Luminance
i. With OpticaLight, luminance measurements
should be taken 20-ft to 30-ft away for most
accurate readings.
d. Measure Ambient Luminance (only required if
there is significant contribution of light from
adjacent sites)
One Lane
Measurement Grid
Two Lane
Measurement Grid
Single Luminaire
Measurement Grid
Optica Light App Konica Minolta % Difference
0.57 1.07 47%
0.31 0.44 30%
1.7 1.9 11%
1.8 1.97 9%
2.4 2.9 17%
0.65 0.86 24%
0.48 0.7 31%
Low 0.49
1.13 1.29 24%
Distant Measurements
Optica Light App Konica Minolta % Difference
1.6 1.88 15%
6.1 6.9 12%
2.1 2.4 13%
0.33 0.44 25%
0.51 0.67 24%
0.32 0.39 18%
0.66 0.69 4%
0.41 0.43 5%
0.33 0.38 13%
1.5 1.55 3%
5.7 6 5%
0.13 0.2 35%
0.04 0.05 20%
1.52 1.69 15%
Near Measurements
City of Bozeman –Street Lighting
Luminance Method of Measurement
The City of Bozeman Street Lighting Standards are based on roadway luminance criteria.
Luminance is the intensity of light per unit area that is emitted from a surface in a given direction,
expressed as candela per square meter (cd/m2).The luminance of the roadway surface is the light
reflected off of the pavement toward a driver.Accurate luminance measurements require a
calibrated luminance meter with a 1/3 –degree measuring angle and +/-2%accuracy.Konica
Minolta produces very high quality luminance meters the LS-160 is the current model offered by
Konica Minolta (http://sensing.konicaminolta.us/products/ls-160-luminance-meter/),and the
Konica Minolta LS-110 can be rented from Advanced Test Equipment Rentals
(http://www.atecorp.com/products/minolta/ls-110.aspx).
For preliminary testing,there is a photographic luminance
mapping application from OpticaLight (website)for iPad and
iPhone (https://itunes.apple.com/us/app/opticalight-
candela/id1086540410?mt=8).The OpticaLight App was
tested and compared to measurements from a calibrated
Konica Minolta LS-110 luminance meter.The accuracy of
the OpticaLight App was found to be more accurate for
measurements that were taken at close range (20ft to 30ft),
and less accurate for more distant measurements.
Konica Minolta LS-160
Luminance Meter
OpticaLight Photo Luminance Mapping App OpticaLight App vs. Konica Minolta
LS-110 Luminance Meter
1/4 SP
1/4 SP
Luminance Measurement Grid
1/4 SP
1/4 SP
One-Lane
Measurement Grid
Two-Lane
Measurement Grid
Luminance Measurement Grid
1 x Mounting Height (MH)
1 x MH
1 x MH
Single Luminaire
Measurement Grid
City of Bozeman –Street Lighting
Luminance Method of Measurement
OpticaLight Application Luminance Mapped Images
City of Bozeman –Street Lighting
Luminance Method of Measurement
OpticaLight Application Luminance Mapped Images
City of Bozeman –Street Lighting
Luminance Method of Measurement
OpticaLight Application Luminance Mapped Images
City of Bozeman –Street Lighting
Luminance Method of Measurement
OpticaLight Application Luminance Mapped Images
City of Bozeman –Street Lighting
Luminance Method of Measurement
OpticaLight Application Luminance Mapped Images
City of Bozeman –Street Lighting
Luminance Method of Measurement
OpticaLight Application Luminance Mapped Images
City of Bozeman –Street Lighting
Luminance Method of Measurement
OpticaLight Application Luminance Mapped Images