INDIANA DEPARTMENT OF TRANSPORTATION—2013 DESIGN MANUAL CHAPTER 78 Highway Lighting NOTE: This chapter is currently being re-written and its content will be included in Chapter 502 in the future. Design Revision Sections Affected Memorandum Date 13-12 June 2013 78-3.04, 78-5.0, 78-6.0, 78-7.0, Figure 78-5B, Figure 78-5C 14-01 Feb. 2014 Ch. 75, 76, 77, 78 superseded by Ch. 502 TABLE OF CONTENTS LIST OF FIGURES ......................................................................................................................... 4 78-1.0 GENERAL .......................................................................................................................... 5 78-1.01 References .................................................................................................................... 5 78-1.02 Definitions of Terms ..................................................................................................... 6 78-1.03 State and Local Responsibilities ................................................................................... 8 78-1.04 Lighting Studies .......................................................................................................... 10 78-2.0 WARRANTS .................................................................................................................... 10 78-2.01 Freeway ....................................................................................................................... 11 78-2.02 Interchange ................................................................................................................. 12 78-2.03 Warrants for Street or Highway Other Than a Freeway ............................................. 12 78-2.04 Highway-Sign Lighting .............................................................................................. 13 78-2.05 Rest Area .................................................................................................................... 13 78-2.06 Truck Weigh Station ................................................................................................... 13 78-2.07 Bridge Structure .......................................................................................................... 13 78-2.08 Tunnel ......................................................................................................................... 14 78-2.09 Other Location ............................................................................................................ 14 78-2.10 Reduction or Removal of Lighting ............................................................................. 14 78-3.0 LIGHTING EQUIPMENT ............................................................................................... 16 78-3.01 Foundation .................................................................................................................. 16 78-3.02 Light Standard, or Pole ............................................................................................... 17 78-3.03 Mast Arm .................................................................................................................... 18 78-3.04 Luminaire [Rev. June 2013] ....................................................................................... 19 78-3.04(01) Light Source [Rev. June 2013] ........................................................................ 19 78-3.04(02) Optical System [Rev. June 2013] ..................................................................... 21 78-3.04(03) Regulation of Input Voltage/Ballast [Rev. June 2013] .................................... 21 78-3.04(04) Housing Unit [Rev. June 2013] ....................................................................... 22 78-3.05 Other Equipment ........................................................................................................ 22 78-4.0 LIGHTING METHODOLOGIES .................................................................................... 23 78-4.01 Illuminance ................................................................................................................. 23 78-4.02 Luminance .................................................................................................................. 23 78-4.03 Small-Target Visibility (STV) .................................................................................... 24 78-5.0 DESIGN PROCEDURE [Rev. June 2013] ...................................................................... 24 78-5.01 Computerized Design [Rev. June 2013] ..................................................................... 25 78-5.02 Design Process [Rev. June 2013] ............................................................................... 25 78-5.02(01) Spot Lighting [Added June 2013] ..................................................................... 25 Page 2 2013 Indiana Design Manual, Ch. 78 78-5.02(02) Luminaire Replacement or Partial Modernizations [Added June 2013] ........... 26 78-5.02(03) New Lighting System or Full Modernizations [Added June 2013] .................. 28 78-5.02(04) Design-Build Projects [Added June 2013] ........................................................ 32 78-6.0 DESIGN CONSIDERATIONS ........................................................................................ 35 78-6.01 Roadway Classification .............................................................................................. 36 78-6.02 Design Criteria [Rev. June 2013] ............................................................................... 37 78-6.03 Equipment Considerations .......................................................................................... 38 78-6.03(01) Light Distribution ............................................................................................. 38 78-6.03(02) Mounting Height .............................................................................................. 40 78-6.03(03) Coefficient of Utilization ................................................................................. 40 78-6.03(04) Light-Loss Factor (Maintenance Factor) [Rev. June 2013] ............................. 40 78-6.04 System Configuration ................................................................................................. 41 78-6.05 Roadside-Safety Considerations ................................................................................. 41 78-6.06 Other Considerations .................................................................................................. 44 78-6.07 Voltage Drop Determination [Rev. June 2013] .......................................................... 45 78-7.0 HIGH-MAST LIGHTING DESIGN [Rev. June 2013] .................................................... 47 78-8.0 EXAMPLE COMPUTATIONS ....................................................................................... 49 FIGURES ...................................................................................................................................... 57 2013 Indiana Design Manual, Ch. 78 Page 3 LIST OF FIGURES Figure Title 78-2A Minimum Volumes for Complete Interchange Lighting 78-2B Editable Highway Lighting Accident Warrant Analysis Worksheet 78-2C Appendices for Highway Lighting Accident Warrant Analysis Worksheet 78-3A Typical Luminaire 78-3B Mast Arm Rise Versus Length 78-5A Lamp Data 78-5B Service Cost per Year for Luminaire Replacement or Partial Modernization [Added June 2013] 78-5C Service Cost per Year for New or Fully Modernized Lighting [Added June 2013] 78-6A INDOT Lighting Design Parameters 78-6B INDOT Illuminance Design Criteria 78-6C Luminaire Geometry 78-6D Luminaire Classification System 78-6E Guide for Luminaire Lateral Light Type and Placement 78-6F Plan View for Luminaire Coverage 78-6G Sample Coefficient-of-Utilization Curve 78-6H Roadway Luminaire Dirt Depreciation Factors 78-6 I Lighting System Configurations 78-6J Partial Interchange Lighting 78-6K Breakaway Support Stub Clearance Diagram 78-6L Light Standard Treatment (Fill Slopes 4:1 or Steeper) 78-6M Pole Clearances for Ramp Gores 78-6N Design Amperes for Various Luminaires 78-6O Copper Wire Resistance 78-6P Voltage Drop Calculations (Example 78-6.1) 78-7A Number of Luminaires for High-Mast Tower 78-7B Height of Retaining Wall at High-Mast-Tower Concrete Pad 78-8A Urban Collector Highway (Example 78-8.1) 78-8B Coefficient-of-Utilization Curve (M-S-II Luminaire) 78-8C Sample Isolux Diagram (Example 78-8.1) 78-8D Unadjusted Illumination Values (Example 78-8.1) 78-8E Urban Interchange Lighting 78-8F Sample Isolux Diagram (Example 78-8.2) 78-8G Interchange Lighting Layout (Example 78-8.2) 78-8H Unadjusted Illumination Values (Example 78-8.2) Page 4 2013 Indiana Design Manual, Ch. 78 CHAPTER 78 HIGHWAY LIGHTING 78-1.0 GENERAL The purpose of highway lighting is to provide a safe and comfortable environment for the night- time driver. Due to the voluminous nature of highway-lighting-system design, it is impractical for this Chapter to provide a complete highway-lighting-design guide. For additional design information, the designer is encouraged to review the latest edition of the references listed in Section 78-1.01. The intent of this Chapter is to provide the user with a synopsis of the highway- lighting-design process and to provide INDOT’s criteria, policies, and procedures regarding these issues. 78-1.01 References For additional information on highway lighting, the designer should review the publications as follows; 1. An Informational Guide for Roadway Lighting, AASHTO; 2. Roadway Lighting Handbook, FHWA; 3. Roadway Lighting Handbook, Addendum “Designing the Lighting System - Using Pavement Luminance,” FHWA; 4. Roadway Lighting, RP-8, Illuminating Engineering Society (not used on an INDOT project); 5. NCHRP Report No. 152, Warrants for Highway Lighting, TRB (not used on an INDOT project); 6. NCHRP Report No. 256, Partial Lighting of Interchanges, TRB (not used on an INDOT project); 7. Chapter 49, “Roadside Safety,” Indiana Design Manual, INDOT; 2013 Indiana Design Manual, Ch. 78 Page 5 8. Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals, AASHTO; 9. INDOT Standard Drawings, INDOT; 10. INDOT Standard Specifications, INDOT; 11. National Electrical Code; and 12. National Electric Safety Code. 78-1.02 Definitions of Terms The following defines the more commonly used terms in highway lighting. 1. Average Maintained Illuminance. The average level of horizontal illuminance on the roadway pavement once the output of the lamp and luminaire is diminished by the maintenance factors; expressed in average footcandles for the pavement area. 2. Candela (cd). The unit of luminous intensity. 2 3. Candela per Square Foot (cd/ft ). The unit of photometric brightness (luminance). The unit is equal to the uniform luminance of a perfectly diffusing surface emitting or 2 reflecting light at the rate of one1 lm/ft or the average luminance of a surface emitting or reflecting light at that rate. 4. Effective Mounting Height. The vertical distance between the foundation of the light standard and the center of the light source in the luminaire. 5. Glare. The optical sensation produced by luminance within the visual field that is sufficiently greater than the luminance to which the eyes are adapted and which causes annoyance, discomfort, or loss in visual performance and visibility. 6. Illuminance. The density of the luminous flux incident on a surface. It is the quotient of the luminous flux divided by the area of the surface where the latter is uniformly illuminated. 7. Lamp Lumens Depreciation Factor (LLD). A depreciation factor that indicates the decrease in a lamp’s initial lumen output over time. For design calculations, the initial Page 6 2013 Indiana Design Manual, Ch. 78 lamp lumen value is reduced by an LLD to compensate for the anticipated lumen reduction. 8. Longitudinal Roadway Line. A line along the roadway parallel to the curb or shoulder line. 9. Lumen (lm). A unit of measure of the quantity of light. 10. Luminaire. A complete lighting unit consisting of a lamp or lamps together with the parts designed to distribute the light, to position and protect the lamps, and to connect the lamps to the power supply. 11. Luminaire Dirt Depreciation Factor (LDD). A depreciation factor that indicates the expected reduction of a lamp’s initial lumen output due to the accumulation of dirt on or within the luminaire over time. 12. Luminance. The luminous intensity of a surface in a given direction per unit of projected area of the surface as viewed from that direction. 2 13. Footcandle. The illuminance on a surface of 1 ft in area on which there is uniformly distributed a light flux of one lm, or the illuminance produced on a surface for which all points are at a distance of 1 ft from a uniform point source of one cd. 14. Maintenance Factor (MF). A combination of light-loss factors used to denote the reduction of the illumination for a given area after a period of time compared to the initial illumination on the same area (MF = LLD x LDD). 15. Mounting Height. The vertical distance between the roadway surface and the center of the light source in the luminaire. 16. Nadir. The vertical axis which passes through the center of the luminaire light source. 17. Spacing. The distance in feet between successive lighting units. 18. Transverse Roadway Line. A line across the roadway that is perpendicular to the curb or shoulder line. 19. Uniformity Ratio. The ratio of average maintained lux of illuminance on the pavement to the maintained lux at the point of minimum illuminance on the pavement. A uniformity 2013 Indiana Design Manual, Ch. 78 Page 7 ratio of 3:1 means that the average lux value on the pavement is three times the lux value at the point of least illuminance on the pavement. 78-1.03 State and Local Responsibilities The following describes the responsibilities between the Department and a local government agency for a lighting installation along a State-maintained highway. 1. INDOT Jurisdiction. The Department may illuminate a portion of a State, U.S., or Interstate highway outside incorporated city or town limits that satisfies the warranting conditions provided in Section 78-2.0. INDOT will not provide illumination inside city or town incorporated limits, except along an Interstate route. 2. Local Jurisdiction. A local governmental agency may install lighting along a State highway within its jurisdictional limits provided the agency finds sufficient benefit in the form of convenience, safety, policing, community promotion, public relations, etc. The local agency will develop appropriate warranting guidelines for installing lighting. If the city or town has not developed warrants, the Department warrants in Section 78-2.0, or those listed in the references in Section 78-1.01, should be considered. The local agency will be responsible for installing, maintaining, and operating the lighting facilities. The plans for lighting a State highway within local jurisdictional limits must meet Department criteria and must receive INDOT approval through a formal agreement prior to installation. The plans should be submitted for review to the Traffic Administration Manager, Traffic Engineering Division 3. Installation. Installation by the Department will be done under the Department’s normal programming and contracting procedures. The installation, however, may be performed through an agreement with a utility company. 4. Operation. For each location where the Department is responsible for paying the energy costs, an agreement must be negotiated between the local utility company and the Department for payment of the electrical current. The current may or may not be metered. All bills should be submitted through the district Office of Traffic for payment. 5. Maintenance. Maintenance of a Department lighting system may be furnished by agreement with a local utility company, by an independent lighting contractor, or by trained INDOT personnel. Page 8 2013 Indiana Design Manual, Ch. 78 6. Agreement. An agreement for a Department lighting system should be prepared according to INDOT agreement policy. According to Indiana Code (IC, 8-23-22-2, and amendments thereto), the Department is required to enter into an agreement for sharing the utility costs. 7. Existing System. Where an agreement between INDOT and a local agency on maintenance and operation of an existing lighting system along a State-maintained highway cannot be resolved, the following will apply. a. If a system installed by the Department is annexed into the city or town corporate limits and the local agency does not agree to take over the maintenance and operation costs, the system should be considered for removal if a cost analysis shows such action to be cost effective. A removal study as defined in Section 78- 2.10 should be conducted. b. If the system was installed by the local agency and the local agency is no longer willing to pay for the operation and maintenance costs, INDOT will determine if the system is warranted. If it is warranted and is outside the incorporation limits, the Department may take over the responsibilities for maintaining and operating the system. If the system is not warranted, the local agency may be requested to remove the system. If the local agency will not remove the system, the Department may remove it as described in Section 78-2.10. c. If the system was installed in accordance with an agreement entered into between the Department and the local governmental agency, and the agency is no longer abiding by the stipulations of the agreement, the Department may conduct a study to determine if the system is warranted. If continuation of the system is not found to be cost effective, INDOT may remove it as described in Section 78-2.10. 8. Other Construction Project. Where a proposed construction project (e.g., roadway reconstruction project) is within city or town incorporation limits, the following will apply relative to lighting. a. If the existing lighting system is owned by the local agency and the project requires the system to be relocated, INDOT will be responsible for all relocation expenses. b. If the existing lighting system is owned by a utility company and the project requires the system to be relocated, the utility company will be responsible for all relocation expenses. 2013 Indiana Design Manual, Ch. 78 Page 9 c. If there is no existing lighting and it is requested by the local agency, INDOT will include the lighting system in the project if the local agency agrees to pay for all installation costs and will take responsibility for the operation and maintenance of the system. d. If the existing luminaire arms are mounted on utility company poles and the lighting hardware is owned by the local agency, INDOT will be responsible only for the relocation expenses associated with the lighting hardware, if requested by the local agency. No upgrades in the existing lighting are accomplished under this option. 78-1.04 Lighting Studies If a request is made for a new lighting installation along a State-maintained highway outside of incorporation limits, the following procedure should be used. 1. Lighting Request. The local agency or other local group seeking the lighting system is required to submit a request to the district Traffic Team petitioning the Department to consider the installation of a new lighting system along the State highway. 2. Lighting Study. The district Traffic Team will conduct a study to determine if the request justifies further action. Each lighting study report should include the Highway Lighting Accident Warrant Analysis. 3. Programming. If the location warrants lighting and it is outside the corporate limits, the district Traffic Team will request the Planning Division to initiate a project to provide lighting at the location. 78-2.0 WARRANTS Providing lighting along every highway is not practical or cost effective. The district Traffic Team will be responsible for determining if the lighting system is economically justified along a State-maintained highway. It is the Department’s practice to only provide lighting if there is an average of seven night accidents per year, and the night-to-day ratio of accidents is greater than 0.5. A blank Highway Lighting Accident Analysis Worksheet is shown as Figure 78-2B. An editable version of this form may also be found on the Department’s website at www.in.gov/dot/div/contracts/design/dmforms/. The appendices referred to in the worksheet are Page 10 2013 Indiana Design Manual, Ch. 78